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Contemporary Educational Psychology/Behaviorism: Changes in What Students Do

Behaviorism is a perspective on learning that focuses on changes in individuals’ observable behaviors—changes in what people say or do. At some point we all use this perspective, whether we call it “behaviorism” or something else. The first time that I drove a car, for example, I was concerned primarily with whether I could actually do the driving, not with whether I could describe or explain how to drive. And for another example: when I reached the point in life where I began cooking meals for myself, I was more focused on whether I could actually produce edible food in a kitchen than with whether I could explain my recipes and cooking procedures to others. And still another example—one often relevant to new teachers: when I began my first year of teaching, I was more focused on doing the job of teaching—on day-to-day survival—than on pausing to reflect on what I was doing.

Note that in all of these examples, focusing attention on behavior instead of on “thoughts” may have been desirable at that moment, but not necessarily desirable indefinitely or all of the time. Even as a beginner, there are times when it is more important to be able to describe how to drive or to cook than to actually do these things. And there definitely are many times when reflecting on and thinking about teaching can improve teaching itself. (As a teacher-friend once said to me, “Don’t just do something; stand there!”) But neither is focusing on behavior necessarily less desirable than focusing on students’ “inner” changes, such as gains in their knowledge or their personal attitudes. If you are teaching, you will need to attend to all forms of learning in students, whether inner or outward.

In classrooms, behaviorism is most useful for identifying relationships between specific actions by a student and the immediate precursors and consequences of the actions. It is less useful for understanding changes in students’ thinking; for this purpose we need a more cognitive (or thinking-oriented) theory, like the ones described later in this chapter. This fact is not really a criticism of behaviorism as a perspective, but just a clarification of its particular strength or source of usefulness, which is to highlight observable relationships among actions, precursors and consequences. Behaviorists use particular terms (or “lingo,” some might say) for these relationships. They also rely primarily on two basic images or models of behavioral learning, called respondent (or “classical”) conditioning and operant conditioning. The names are derived partly from the major learning mechanisms highlighted by each type, which I describe next.

Respondent Conditioning: Learning New Associations with Prior Behaviors
As originally conceived, respondent conditioning (sometimes also called classical conditioning) begins with the involuntary responses to particular sights, sounds, or other sensations (Lavond & Steinmetz, 2003). When I receive an injection from a nurse or doctor, for example, I cringe, tighten my muscles, and even perspire a bit. Whenever a contented, happy baby looks at me, on the other hand, I invariably smile in response. I cannot help myself in either case; both of the responses are automatic. In humans as well as other animals, there is a repertoire or variety of such specific, involuntary behaviors. At the sound of a sudden loud noise, for example, most of us show a “startle” response—we drop what we are doing (sometimes literally!), our heart rate shoots up temporarily, and we look for the source of the sound. Cats, dogs, and many other animals (even fish in an aquarium) show similar or equivalent responses.

Involuntary stimuli and responses were first studied systematically early in the twentieth century by the Russian scientist Ivan Pavlov (1927). Pavlov’s most well-known work did not involve humans, but dogs, and specifically their involuntary tendency to salivate when eating. He attached a small tube to the side of dogs’ mouths that allowed him to measure how much the dogs salivated when fed. But he soon noticed a “problem” with the procedure: as the dogs gained experience with the experiment, they often salivated before they began eating. In fact the most experienced dogs sometimes began salivating before they even saw any food, simply when Pavlov himself entered the room! The sight of the experimenter, which had originally been a neutral experience for the dogs, became associated with the dogs’ original salivation response. Eventually, in fact, the dogs would salivate at the sight of Pavlov even if he did not feed them.

This change in the dogs’ involuntary response, and especially its growing independence from the food as stimulus, eventually became the focus of Pavlov’s research. Psychologists named the process respondent conditioning because it describes changes in responses to stimuli (though some have also called it “classical conditioning” because it was historically the first form of behavioral learning to be studied systematically). Respondent conditioning has several elements, each with a special name. To understand these, look at /Figure 1/, and imagine a dog (such as my own, named Ginger) prior to any conditioning. At the beginning Ginger salivates (an unconditioned response (UR)) only when she actually tastes her dinner (an unconditioned stimulus (US)). As time goes by, however, a neutral stimulus—such as the sound of opening a bag containing fresh dog food—is continually paired with the eating/tasting experience. Eventually the neutral stimulus becomes able to elicit salivation even before any dog food is offered to Ginger, or even if the bag of food is empty! At this point the neutral stimulus is called a conditioned stimulus (UCS) and the original response is renamed as a conditioned response (CR). Now, after conditioning, Ginger salivates merely at the sound of opening any large bag, regardless of its contents. (I might add that Ginger also engages in other conditioned responses, such as looking hopeful and following me around the house at dinner time.)

Respondent Conditioning and Students
“OK,” you may be thinking, “Respondent conditioning may happen to animals. But does anything like it happen in classrooms?” It might seem like not much would, since teaching is usually about influencing students’ conscious words and thoughts, and not their involuntary behaviors. But remember that schooling is not just about encouraging thinking and talking. Teachers, like parents and the public, also seek positive changes in students’ attitudes and feelings—attitudes like a love for learning, for example, and feelings like self-confidence. It turns out that respondent conditioning describes these kinds of changes relatively well.

Consider, for example, a child who responds happily whenever meeting a new person who is warm and friendly, but who also responds cautiously or at least neutrally in any new situation. Suppose further that the “new, friendly person” in question is you, his teacher. Initially the child’s response to you is like an unconditioned stimulus: you smile (the unconditioned stimulus) and in response he perks up, breathes easier, and smiles (the unconditioned response). This exchange is not the whole story, however, but merely the setting for an important bit of behavior change: suppose you smile at him while standing in your classroom, a “new situation” and therefore one to which he normally responds cautiously. Now respondent learning can occur. The initially neutral stimulus (your classroom) becomes associated repeatedly with the original unconditioned stimulus (your smile) and the child’s unconditioned response (his smile). Eventually, if all goes well, the classroom becomes a conditioned stimulus in its own right: it can elicit the child’s smiles and other “happy behaviors” even without your immediate presence or stimulus. /Figure 2a/ diagrams the situation graphically. When the change in behavior happens, you might say that the child has “learned” to like being in your classroom. Truly a pleasing outcome for both of you!

But less positive or desirable examples of respondent conditioning also can happen. Consider a modification of the example that I just gave. Suppose the child that I just mentioned did not have the good fortune of being placed in your classroom. Instead he found himself with a less likeable teacher, whom we could simply call Mr. Horrible. Instead of smiling a lot and eliciting the child’s unconditioned “happy response,” Mr. Horrible often frowns and scowls at the child. In this case, therefore, the child’s initial unconditioned response is negative: whenever Mr. Horrible directs a frown or scowl at the child, the child automatically cringes a little, his eyes widen in fear, and his heart beat races. If the child sees Mr. Horrible doing most of his frowning and scowling in the classroom, eventually the classroom itself will acquire power as a negative conditioned stimulus. Eventually, that is, the child will not need Mr. Horrible to be present in order to feel apprehensive; simply being in the classroom will be enough. Figure 2b diagrams this unfortunate situation. Obviously it is an outcome to be avoided, and in fact does not usually happen in such an extreme way. But hopefully it makes the point: any stimulus that is initially neutral, but that gets associated with an unconditioned stimulus and response, can eventually acquire the ability to elicit the response by itself. Anything—whether it is desirable or not.

The changes described in these two examples are important because they affect students’ attitude about school, and therefore also their motivation to learn. In the positive case, the child becomes more inclined to please the teacher and to attend to what he or she has to offer; in the negative case, the opposite occurs. Note that even though the changes are elicited by events external to the child, the child’s newly learned attitude is best thought of as “inside” or belonging to the child—or intrinsic. The new responses suggest that the child has acquired one type of intrinsic motivation, meaning a desire or tendency to direct attention and energy in a particular way that originates from the child himself or herself. It is sometimes contrasted extrinsic motivation, which is a tendency to direct attention and energy that originates from outside of the child. As we will see, classical conditioning is one way to influence students’ intrinsic motivation, but not the only way to develop it. Many strategies for influencing students’ motivations focus less on their behavior, and more on their thoughts and beliefs about themselves and about what they are learning. I describe these in detail in .././Chapter 6/ (the chapter called “Student Motivation”). First, though, let us look at three other features of classical conditioning that complicate the picture a bit, but also render conditioning a more accurate or appropriate description of students’ learning.

Extinction
This term does not refer to the fate of dinosaurs, but to the disappearance of a link between the conditioned stimulus and the conditioned response. Imagine a third variation on the conditioning “story” described above. Suppose, as I suggested above, that the child begins by associating your happy behaviors—your smiles—to his being present in the classroom, so that the classroom itself becomes enough to elicit his own smiles. But now suppose there is a sad turn of events: you become sick and must therefore leave the classroom in the middle of the school year. A substitute is called in who is not Mr. Horrible, but simply someone who is not very expressive, someone we can call Ms. Neutral. At first the child continues to feel good (that is, to smile) whenever present in the classroom. But because the link between the classroom and your particular smiles is no longer repeated or associated, the child’s response gradually extinguishes, or fades until it has disappeared entirely. In a sense the child’s initial learning is “unlearned.”

Extinction can also happen with negative examples of classical conditioning. If Mr. Horrible leaves mid-year (perhaps because no one could stand working with him any longer!), then the child’s negative responses (cringing, eyes widening, heart beat racing, and so on) will also extinguish eventually. Note, though, that whether the conditioned stimulus is positive or negative, extinction does not happen suddenly or immediately, but unfolds over time. This fact can sometimes obscure the process if you are a busy teacher attending to many students.

Generalization
When Pavlov studied conditioning in dogs, he noticed that the original conditioned stimulus was not the only neutral stimulus that elicited the conditioned response. If he paired a particular bell with the sight of food, for example, so that the bell became a conditioned stimulus for salivation, then it turned out that other bells, perhaps with a different pitch or type or sound, also acquired some ability to trigger salivation—though not as much as the original bell. Psychologists call this process generalization, or the tendency for similar stimuli to elicit a conditioned response. The child being conditioned to your smile, for example, might learn to associate your smile not only with being present in your own classroom, but also to being present in other, similar classrooms. His conditioned smiles may be strongest where he learned them initially (that is, in your own room), but nonetheless visible to a significant extent in other teachers’ classrooms. To the extent that this happens, he has generalized his learning. It is of course good news; it means that we can say that the child is beginning to “learn to like school” in general, and not just your particular room. Unfortunately, the opposite can also happen: if a child learns negative associations from Mr. Horrible, the child’s fear, caution, and stress might generalize to other classrooms as well. The lesson for teachers is therefore clear: we have a responsibility, wherever possible, to make classrooms pleasant places to be.

Discrimination
Generalization among similar stimuli can be reduced if only one of the similar stimuli is associated consistently with the unconditioned response, while the others are not. When this happens, psychologists say that discrimination learning has occurred, meaning that the individual has learned to distinguish or respond differently to one stimulus than to another. From an educational point of view, discrimination learning can be either desirable or not, depending on the particulars of the situation. Imagine again (for the fourth time!) the child who learns to associate your classroom with your smiles, so that he eventually produces smiles of his own whenever present in your room. But now imagine yet another variation on his story: the child is old enough to attend middle school, and therefore has several teachers across the day. You—with your smiles—are one, but so are Mr. Horrible and Ms. Neutral. At first the child may generalize his classically conditioned smiles to the other teachers’ classrooms. But the other teachers do not smile like you do, and this fact causes the child’s smiling to extinguish somewhat in their rooms. Meanwhile, you keep smiling in your room. Eventually the child is smiling only in your room and not in the other rooms. When this happens, we say that discrimination has occurred, meaning that the conditioned associations happen only to a single version of the unconditioned stimuli—in this case, only to your smiles, and not to the (rather rare) occurrences of smiles in the other classrooms. Judging by his behavior, the child is making a distinction between your room and others’.

In one sense the discrimination in this story is unfortunate in that it prevents the child from acquiring a liking for school that is generalized. But notice that an opposing, more desirable process is happening at the same time: the child is also prevented from acquiring a generalized dislike of school. The fear producing stimuli from Mr. Horrible, in particular, become discriminated from the happiness-producing smiles from you, so the child’s learns to confine his fearful responses to that particular classroom, and does not generalize them to other “innocent” classrooms, including your own. This is still not an ideal situation for the student, but maybe it is more desirable than disliking school altogether.

Operant Conditioning: New Behaviors Because of New Consequences
Instead of focusing on associations between stimuli and responses, operant conditioning focuses on the effects of consequences on behaviors. The operant model of learning begins with the idea that certain consequences tend to make certain behaviors happen more frequently. If I compliment a student for a good comment during a discussion, there is more chance that I will hear comments from the student more often in the future (and hopefully they will also be good ones!). If a student tells a joke to several classmates and they laugh at it, then the student is more likely to tell additional jokes in the future. And so on.

As with respondent conditioning, the original research about this model of learning was not done with people, but with animals. One of the pioneers in the field was a Harvard professor named B. F. Skinner, who published numerous books and articles about the details of the process and who pointed out many parallels between operant conditioning in animals and operant conditioning in humans (1938, 1948, 1988). Skinner observed the behavior of rather tame laboratory rats (not the unpleasant kind that sometimes live in garbage dumps). He or his assistants would put them in a cage that contained little except a lever and a small tray just big enough to hold a small amount of food. (Figure 3 shows the basic set-up, which is sometimes nicknamed a “Skinner box.”) At first the rat would sniff and “putter around” the cage at random, but sooner or later it would happen upon the lever and eventually happen to press it. Presto! The lever released a small pellet of food, which the rat would promptly eat. Gradually the rat would spend more time near the lever and press the lever more frequently, getting food more frequently. Eventually it would spend most of its time at the lever and eating its fill of food. The rat had “discovered” that the consequence of pressing the lever was to receive food. Skinner called the changes in the rat’s behavior an example of operant conditioning, and gave special names to the different parts of the process. He called the food pellets the reinforcement and the lever-pressing the operant(because it “operated” on the rat’s environment).

Skinner and other behavioral psychologists experimented with using various reinforcers and operants. They also experimented with various patterns of reinforcement (or schedules of reinforcement), as well as with various cues or signals to the animal about when reinforcement was available. It turned out that all of these factors—the operant, the reinforcement, the schedule, and the cues—affected how easily and thoroughly operant conditioning occurred. For example, reinforcement was more effective if it came immediately after the crucial operant behavior, rather than being delayed, and reinforcements that happened intermittently (only part of the time) caused learning to take longer, but also caused it to last longer.

Operant Conditioning and Students’ Learning
As with respondent conditioning, it is important to ask whether operant conditioning also describes learning in human beings, and especially in students in classrooms. On this point the answer seems to be clearly “yes.” There are countless classroom examples of consequences affecting students’ behavior in ways that resemble operant conditioning, although the process certainly does not account for all forms of student learning (Alberto & Troutman, 2005). Consider the following examples. In most of them the operant behavior tends to become more frequent on repeated occasions:
 * A seventh-grade boy makes a silly face (the operant) at the girl sitting next to him. Classmates sitting around them giggle in response (the reinforcement).
 * A kindergarten child raises her hand in response to the teacher’s question about a story (the operant). The teacher calls on her and she makes her comment (the reinforcement).
 * Another kindergarten child blurts out her comment without being called on (the operant). The teacher frowns ignores this behavior, but before the teacher calls on a different student, classmates are listening attentively (the reinforcement) to the student even though he did not raise his hand as he should have.
 * A twelfth-grade student—a member of the track team—runs one mile during practice (the operant). He notes the time it takes him as well as his increase in speed since joining the team (the reinforcement).
 * A child who is usually very restless sits for five minutes doing an assignment (the operant). The teaching assistant compliments him for working hard (the reinforcement).
 * A sixth-grader takes home a book from the classroom library to read overnight (the operant). When she returns the book the next morning, her teacher puts a gold star by her name on a chart posted in the room (the reinforcement).

Hopefully these examples are enough to make four points about operant conditioning. First, the process is widespread in classrooms—probably more widespread than respondent conditioning. This fact makes sense, given the nature of public education: to a large extent, teaching is about making certain consequences for students (like praise or marks) depend on students’ engaging in certain activities (like reading certain material or doing assignments). Second, learning by operant conditioning is not confined to any particular grade, subject area, or style of teaching, but by nature happens in nearly every imaginable classroom. Third, teachers are not the only persons controlling reinforcements. Sometimes they are controlled by the activity itself (as in the track team example), or by classmates (as in the “giggling” example). A result of all of the above points is a fourth: that multiple examples of operant conditioning often happen at the same time. /The Case Study/ for this chapter (The Decline and Fall of Jane Gladstone) suggests how this happened to someone completing student teaching.

Because operant conditioning happens so widely, its effects on motivation are a bit more complex than the effects of respondent conditioning. As in respondent conditioning, operant conditioning can encourage intrinsic motivation to the extent that the reinforcement for an activity can sometimes be the activity itself. When a student reads a book for the sheer enjoyment of reading, for example, he is reinforced by the reading itself; then we often say that his reading is “intrinsically motivated.” More often, however, operant conditioning stimulates both intrinsic and extrinsic motivation at the same time. The combining of both is noticeable in the examples that I listed above. In each example, it is reasonable to assume that the student felt intrinsically motivated to some partial extent, even when reward came from outside the student as well. This was because part of what reinforced their behavior was the behavior itself—whether it was making faces, running a mile, or contributing to a discussion. At the same time, though, note that each student probably was also extrinsically motivated, meaning that another part of the reinforcement came from consequences or experiences not inherently part of the activity or behavior itself. The boy who made a face was reinforced not only by the pleasure of making a face, for example, but also by the giggles of classmates. The track student was reinforced not only by the pleasure of running itself, but also by knowledge of his improved times and speeds. Even the usually restless child sitting still for five minutes may have been reinforced partly by this brief experience of unusually focused activity, even if he was also reinforced by the teacher aide’s compliment. Note that the extrinsic part of the reinforcement may sometimes be more easily observed or noticed than the intrinsic part, which by definition may sometimes only be experienced within the individual and not also displayed outwardly. This latter fact may contribute to an impression that sometimes occurs, that operant conditioning is really just “bribery in disguise”—that only the external reinforcements operate on students’ behavior. It is true that external reinforcement may sometimes alter the nature or strength of internal (or intrinsic) reinforcement, but this is not the same as saying that it destroys or replaces intrinsic reinforcement. But more about this issue later! (See especially ../Chapter 6: Student Motivation/.)

Comparing Operant Conditioning and Respondent Conditioning
Operant conditioning is made more complicated, but also more realistic, by many of the same concepts as used in respondent conditioning. In most cases, however, the additional concepts have slightly different meanings in each model of learning. Since this circumstance can make the terms confusing, let me explain the differences for three major concepts used in both models—extinction, generalization, and discrimination. Then I will comment on two additional concepts—schedules of reinforcement and cues—that are sometimes also used in talking about both forms of conditioning, but that are important primarily for understanding operant conditioning. The explanations and comments are also summarized in /Table 2/.

In both respondent and operant conditioning, extinction refers to the disappearance of “something.” In operant conditioning, what disappears is the operant behavior because of a lack of reinforcement. A student who stops receiving gold stars or compliments for prolific reading of library books, for example, may extinguish (i.e. decrease or stop) book-reading behavior. In respondent conditioning, on the other hand, what disappears is association between the conditioned stimulus (the CS) and the conditioned response (CR). If you stop smiling at a student, then the student may extinguish her association between you and her pleasurable response to your smile, or between your classroom and the student’s pleasurable response to your smile.

In both forms of conditioning, generalization means that something “extra” gets conditioned if it is somehow similar to “something.” In operant conditioning, the extra conditioning is to behaviors similar to the original operant. If getting gold stars results in my reading more library books, then I may generalize this behavior to other similar activities, such as reading the newspaper, even if the activity is not reinforced directly. In respondent conditioning, however, the extra conditioning refers to stimuli similar to the original conditioned stimulus. If I am a student and I respond happily to my teacher’s smiles, then I may find myself responding happily to other people (like my other teachers) to some extent, even if they do not smile at me. Generalization is a lot like the concept of transfer that I discussed early in this chapter, in that it is about extending prior learning to new situations or contexts. From the perspective of operant conditioning, though, what is being extended (or “transferred” or generalized) is a behavior, not knowledge or skill.

In both forms of conditioning, discrimination means learning not to generalize. In operant conditioning, though, what is not being overgeneralized is the operant behavior. If I am a student who is being complimented (reinforced) for contributing to discussions, I must also learn to discriminate when to make verbal contributions from when not to make verbal contributions—such as when classmates or the teacher are busy with other tasks. In respondent conditioning, what are not being overgeneralized are the conditioned stimuli that elicit the conditioned response. If I, as a student, learn to associate the mere sight of a smiling teacher with my own happy, contented behavior, then I also have to learn not to associate this same happy response with similar, but slightly different sights, such as a teacher looking annoyed.

In both forms of conditioning, the schedule of reinforcement refers to the pattern or frequency by which “something” is paired with “something else.” In operant conditioning, what is being paired is the pattern by which reinforcement is linked with the operant. If a teacher praises me for my work, does she do it every time, or only sometimes? Frequently or only once in awhile? In respondent conditioning, however, the schedule in question is the pattern by which the conditioned stimulus is paired with the unconditioned stimulus. If I am student with Mr. Horrible as my teacher, does he scowl every time he is in the classroom, or only sometimes? Frequently or rarely?

Behavioral psychologists have studied schedules of reinforcement extensively (for example, Ferster, et al., 1997; Mazur, 2005 ), and found a number of interesting effects of different schedules. For teachers, however, the most important finding may be this: partial or intermittent schedules of reinforcement generally cause learning to take longer, but also cause extinction of learning to take longer. This dual principle is important for teachers because so much of the reinforcement we give is partial or intermittent. Typically, if I am teaching, I can compliment a student a lot of the time, for example, but there will inevitably be occasions when I cannot do so because I am busy elsewhere in the classroom.

For teachers concerned both about motivating students and about minimizing inappropriate behaviors, this is both good news and bad. The good news is that the benefits of my praising students’ constructive behavior will be more lasting, because they will not extinguish their constructive behaviors immediately if I fail to support them every single time they happen. The bad news is that students’ negative behaviors may take longer to extinguish as well, because those too may have developed through partial reinforcement. A student who clowns around inappropriately in class, for example, may not be “supported” by classmates’ laughter every time it happens, but only some of the time. Once the inappropriate behavior is learned, though, it will take somewhat longer to disappear even if everyone—both teacher and classmates—make a concerted effort to ignore (or extinguish) it.

Finally, behavioral psychologists have studied the effects of cues. In operant conditioning, a cue is a stimulus that happens just prior to the operant behavior and that signals that performing the behavior may lead to reinforcement. Its effect is much like discrimination learning in respondent conditioning, except that what is “discriminated” in this case is not a conditioned behavior that is reflex-like, but a voluntary action, the operant. In the original conditioning experiments, Skinner’s rats were sometimes cued by the presence or absence of a small electric light in their cage. Reinforcement was associated with pressing a lever when, and only when, the light was on. In classrooms, cues are sometimes provided by the teacher or simply by the established routines of the class. Calling on a student to speak, for example, can be a cue that if the student does say something at that moment, then he or she may be reinforced with praise or acknowledgement. But if that cue does not occur—if the student is not called on—speaking may not be rewarded. In more everyday, non-behaviorist terms, the cue allows the student to learn when it is acceptable to speak, and when it is not.

Constructivism: Changes in How Students Think
Behaviorist models of learning may be helpful in understanding and influencing what students do, but teachers usually also want to know what students are thinking and how to enrich what students are thinking...(read more...)

Additional Resources
Learning Theories/Behavioralist Theories—a developing Wikibook on this topic, but with less focus on classroom applications. Note misspelling of title—this is necessary to link to the page.

Learning theory (education)—a brief explanation of types of learning theories, but without many examples.

Go Back to Introductory Section to Chapter 2...


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Talk:Using POSper

Jamie had you seen Craig Bass documents? you might get some useful stuff from there: http://www.candocomputerservices.com/tinapos.html Manuel

I've seen it before.. I looked and can't find a license though, so I don't know if it's gfdl or some other thing -Jamie

The site http://www.posper.org looks like one of those search page zombies. Remove or find a "real" home page. Triggerwhiz (talk)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Using POSper


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Talk:Contemporary Educational Psychology/Chapter 2: The Learning Process

I still don't have the knack for using the shortcut syntax for page links within a wikibook there are a few problems for this chapter--subsections are not universally and mutually accessible. I've got to go back and check them all, whilst paying close attention to the syntax. Seems like a "flat" structure is easier to deal with overall for a large online document--I can see why people are favoring it compared to a deep structure.

First, though, I want to get the rest of the content posted for Chapter 2. Then I will fiddle with the links again. Klseifert 14:47, 9 August 2007 (UTC)

p.s.
OK, content has now been posted (mostly), though not yet the "end matter." The Constructivism and Behaviorism sections are inconsistent, though--construc. is posted on main intro page, but behaviorism is linked to a separate page. A parallel structure would be better. Klseifert 16:19, 9 August 2007 (UTC)

Simple end matter has been posted
Now what is missing is: 130.179.184.28 18:37, 9 August 2007 (UTC)
 * Tables and figures--for these I will have to learn the syntax. It seems potentially difficult, but hopefully OK if I take my time.
 * Appropriate links to wikipedia "definitional" articles. I know I'm not supposed to use many of these, but I think there are a few that should be added to this chapter.
 * Check for full, mutual linkages among pages and parts.
 * Question: is there no way in a wiki to do the equivalent of an "anchored link" that I use a lot in Dreamweaver?

(That's me again--I forgot again to sign in. Klseifert 18:38, 9 August 2007 (UTC) )


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Talk:Contemporary Educational Psychology

All basic writing is now posted for all chapters of this book. However I still see these problems:
 * Initial sections of some chapters are too long and should therefore be split up, shortened, and/or moved into separate pages of their own. The intro to each chapter should be kept very short so that the Table of Contents will display easily "above the fold" (so to speak)--i.e. on one average computer screen.
 * The initial anecdotes and stories may need to be deleted or placed elsewhere. I'm not sure they belong in a Wikibook. Maybe move them to Wikisource or Wikiuniversity? Since they are a bit more literary in style, and therefore perhaps cannot be edited in the same way as more expository material without doing violence to their intent? I'm not sure about this.
 * Various links of all sorts need to be added. They include tables and figures, but also links between chapters and sections, and perhaps also with Wikipedia and other external sources.

Readers of the book may, of course, see additional or different problems. Any comments or concerns are therefore welcome. You can put them either here or on my talk page.

KelvinLeeSeifert 15:03, 26 September 2007 (UTC)

What I'm looking for is a useful textbook, which this is not yet. Basically I see it as this: 1. Get the style sheets right. I tried a couple of pages and they looked ... not very good. That is a very simple task. 2. A muddle of pages is not very useful. Provide a way to download the whole book (from title page, to contents, through the chapters one by one.) You know, like a book 3. If you want to put links in, they should not interrupt the text and should be some color other than blue.

I realise that these are primarily software modifications, but it is largely a matter of simplification, not of adding increasingly many options and complexities.

Ross Woods


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User:Firefighter04~enwikibooks

Hi, I am Firefighter04!

title: User:Firefighter04~enwikibooks


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Cyber Guide to ODU Career Management/Get Hands-On/Best Practices

Assessment/Evaluation Review
Establish criteria (potentially a checklist) to gauge Activity, Satisfaction, and Outcomes of our programs and services. Rather than jumping in and editing our evaluations, focus on desired results first...

Service Learning Opportunities/CMC Involvement
As we begin to look at incorporating service learning into the UNIV curriculum, we can become involved in CMC-wide service projects. One suggestion is to take a work day or a work afternoon and work as a team on a project within the community. An example is to do yardwork at an elementary school, maybe one of the schools we partner with (Andrea's programs)

Parent Involvement/Opportunities
Develop a parent volunteer group Publish a parent newsletter in which parents can subscribe if they wish Maintain a parent listserve to keep parents updated on CMC activities Remember that parents can also be our employers - this is another way for us to network


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User talk:Mahboob~enwikibooks

Welcome to Wikibooks. We invite everyone to contribute constructively to our collection. However, pages should not be moved, as you did to Cookbook:Soy Sauce, without good reason. They need to have a name that is both accurate and intuitive. We have some guidelines in place to help with this. Generally, a page should only be moved to a new title if the current name doesn't follow these guidelines. Also, if a page move is being discussed, consensus needs to be reached before anybody moves the page. Take a look at the welcome page to learn more about contributing. Thank you. --Az1568(Talk) 18:11, 9 August 2007 (UTC)

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Mahboob. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Mahboob~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:24, 17 March 2015 (UTC)

Renamed
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title: User talk:Mahboob~enwikibooks


text:
User talk:Fredericknoronha

This is your personal talk page, I can leave you messages here. You may leave me messages at My talk page. --Whiteknight (Page) (Talk) 18:18, 9 August 2007 (UTC)

title: User talk:Fredericknoronha


text:
Contemporary Educational Psychology/Constructivism: Changes in How Students Think

Behaviorist models of learning may be helpful in understanding and influencing what students do, but teachers usually also want to know what students are thinking, and want to enrich what they are thinking. For this aspect of teaching, some of the best help comes from constructivism, which is a perspective on learning focused on how students actively create (or “construct”) knowledge out of experiences. Constructivist models of learning differ among themselves, and one of the most important differences is about how much the model focuses on learners as independent individuals, compared to the social links between an individual and people who may be more expert and who can help the individual to learn (Fosnot, 2005; Rockmore, 2005). For convenience (and because others sometimes use these same terms) I will call these psychological constructivism and social constructivism, even though both versions are in a sense explanations about thinking in individuals.

Psychological Constructivism: The Independent Investigator
The main idea of psychological constructivism is that a person learns by mentally organizing and reorganizing new information or experiences. The organization happens partly by relating new experiences to prior knowledge that is already meaningful and well understood. Stated in this general form, individual constructivism is sometimes associated with a well-known educational philosopher of the early twentieth century, John Dewey (1938/1998). Although Dewey himself did not use the term constructivism in most of his writing, his point of view amounted to a type of constructivism, and he discussed in detail its implications for educators. He argued, for example, that if students indeed learn primarily by building their own knowledge, then teachers should adjust the curriculum to fit students’ prior knowledge and interests as fully as possible. He also argued that a curriculum could only be justified if it related as fully as possible to the activities and responsibilities that students will probably have later, after leaving school. To many educators these days, his ideas may seem merely like good common sense, but they were indeed innovative and progressive at the beginning of the twentieth century.

A more recent example of psychological constructivism is the cognitive theory of Jean Piaget' (Piaget, 2001; Gruber & Voneche, 1995). Piaget described learning as interplay between two mental activities that he called assimilation and accommodation. Assimilation is the interpretation of new information in terms of pre-existing concepts, information or ideas. A preschool child who already understands the concept of bird, for example, might initially label any flying object with this term—even butterflies or mosquitoes. Assimilation is therefore a lot like the idea of generalization in operant conditioning, as well as the idea of transfer that I described at the beginning of this chapter as an enduring concern of teachers. In Piaget’s viewpoint, though, what is being transferred to a new setting is not simply a behavior, as in operant conditioning, but a mental representation for an object or experience.

Assimilation operates jointly with accommodation, which is the revision or modification of pre-existing concepts in terms of new information or experience. The preschooler who initially generalizes the concept of bird to include any flying object, for example, eventually revises the concept to include only particular kinds of flying objects, such as robins and sparrows, and not others, like mosquitoes or airplanes. For Piaget, assimilation and accommodation work together to enrich a child’s thinking and to create what Piaget called cognitive equilibrium, which is a balance between reliance on prior information and openness to new information. At any given time, cognitive equilibrium consists of an ever-growing repertoire of mental representations for objects and experiences. Piaget called each mental representation a schema (all of them together—the plural—was called schemata). A schema was not merely a concept, but an elaborated mixture of vocabulary, actions, and experience related to the concept. A child’s schema for bird, for example, includes not only the relevant verbal knowledge (like knowing how to define the word “bird”), but also the child’s experiences with birds, pictures of birds, and conversations about birds. As assimilation and accommodation about birds and other flying objects operate together over time, the child does not just revise and add to his vocabulary (such as acquiring a new word, “butterfly”), but also adds and remembers relevant new experiences and actions. From these collective revisions and additions the child gradually constructs whole new schemata about birds, butterflies, and other flying objects. In more everyday (but also less precise) terms, Piaget might then say that “the child has learned more about birds.”

Figure 4 diagrams the relationships among the Piagetian version of psychological constructivist learning. Note that the model of learning in the figure is rather “individualistic,” in the sense that it does not say much about how other people involved with the learner might assist in assimilating or accommodating information. Parents and teachers, it would seem, are left lingering on the sidelines, with few significant responsibilities for helping learners to construct knowledge. But the Piagetian picture does nonetheless imply a role for helpful others: someone, after all, has to tell or model the vocabulary needed to talk about and compare birds from airplanes and butterflies! Piaget did recognize the importance of helpful others in his writings and theorizing, calling the process of support or assistance social transmission. But he did not emphasize this aspect of constructivism. Piaget was more interested in what children and youth could figure out on their own, so to speak, than in how teachers or parents might be able to help the young to figure out (Salkind, 2004). Partly for this reason, his theory is often considered less about learning and more about development, which is long-term change in a person resulting from multiple experiences. For the same reason, educators have often found Piaget’s ideas especially helpful for thinking about students’ readiness to learn, another one of the lasting educational issues that I discussed at the beginning of this chapter. I will therefore return to Piaget in Contemporary Educational Psychology/Chapter 3: Student Development, which discusses development and its importance for teaching in more detail.

Social Constructivism: Assisted Performance
Unlike Piaget’s rather individually oriented version of constructivism, some psychologists and educators have explicitly focused on the relationships and interactions between a learner and more knowledgeable and experienced individuals. One early expression of this viewpoint came from the American psychologist Jerome Bruner (1960, 1966, 1996) , who became convinced that students could usually learn more than had been traditionally expected as long as they were given appropriate guidance and resources. He called such support instructional scaffolding—literally meaning a temporary framework, like one used in constructing a building, that allows a much stronger structure to be built within it. In a comment that has been quoted widely (and sometimes disputed), he wrote, “We [constructivist educators] begin with the hypothesis that any subject can be taught effectively in some intellectually honest form to any child at any stage of development” (1960, p. 33). The reason for such a bold assertion was Bruner’s belief in scaffolding—his belief in the importance of providing guidance in the right way and at the right time. When scaffolding is provided, students seem more competent and “intelligent,” and they learn more.

Similar ideas were proposed independently by the Russian psychologist Lev Vygotsky (1978), whose writing focused on how a child’s or novice’s thinking is influenced by relationships with others who are more capable, knowledgeable or expert than the learner. Vygotsky proposed that when a child (or any novice) is learning a new skill or solving a new problem, he or she can perform better if accompanied and helped by an expert than if performing alone—though still not as well as the expert. Someone who has played very little chess, for example, will probably compete against an opponent better if helped by an expert chess player than if competing alone against an opponent. Vygotsky called the difference between solo performance and assisted performance the zone of proximal development (or ZPD for short)—meaning the place or area (figuratively speaking) of immediate change. From this perspective learning is like assisted performance (Tharp & Gallimore, 1991). Initially during learning, knowledge or skill is found mostly “in” the expert helper. If the expert is skilled and motivated to help, then the expert arranges experiences that allow the novice to practice crucial skills or to construct new knowledge. In this regard the expert is a bit like the coach of an athlete—offering help and suggesting ways of practicing, but never doing the actual athletic work himself or herself. Gradually, by providing continued experiences matched to the novice learner’s emerging competencies, the expert-coach makes it possible for the novice or apprentice to appropriate (or "make his or her own") the skills or knowledge that originally resided only with the expert.

In both the psychological and social versions of constructivist learning, the novice is not really “taught” so much as just allowed to learn. The social version of constructivism, however, highlights the responsibility of the expert for making learning possible. He or she must not only have knowledge and skill, but also know how to arrange experiences that make it easy and safe for learners to gain knowledge and skill themselves. These requirements sound, of course, a lot like the requirements for classroom teaching. In addition to knowing what is to be learned, the expert (i.e. the teacher) also has to break the content into manageable parts, offer the parts in a sensible sequence, provide for suitable and successful practice, bring the parts back together again at the end, and somehow relate the entire experience to knowledge and skills already meaningful to the learner. But of course, no one said that teaching is easy!

Implications of Constructivism for Teaching
Fortunately there are strategies that teachers can use for giving students with this kind of help—in fact they are a major theme throughout this book and throughout most preservice teacher education programs. For now, let me just point briefly to two of them, saving complete discussion for later. One strategy that teachers often find helpful is to organize the content to be learned as systematically as possible, because doing this allows the teacher to select and devise learning activities that are more effective. One of the most widely used frameworks for organizing content, for example, is classification scheme proposed by the educator Benjamin Bloom, published with the somewhat imposing title of Taxonomy of Educational Objectives: Handbook #1: Cognitive Domain (Bloom, et al., 1956; Anderson & Krathwohl, 2001). Bloom’s taxonomy, as it is usually called, describes six kinds of learning goals that teachers can in principle expect from students, ranging from simple recall of knowledge to complex evaluation of knowledge. (The levels are defined briefly in Table 3, with examples from “Goldilocks and the Three Bears.”)

Bloom’s taxonomy makes useful distinctions among possible kinds of knowledge needed by students, and therefore potentially helps in selecting activities that truly target students’ “zones of proximal development” in the sense meant by Vygotsky. A student who knows few terms for the species studied in biology unit (a problem at Bloom’s knowledge and comprehension levels), for example, may initially need support at remembering and defining the terms before he or she can make useful comparisons among species (Bloom’s analysis level). Pinpointing the most appropriate learning activities to accomplish this objective remains the job of the teacher-expert (that’s you), but the learning itself has to be accomplished by the student. Put in more social constructivist terms, the teacher arranges a zone of proximal development that allows the student to compare species successfully, but the student still has to construct or appropriate the comparisons for him or herself. A second strategy may be coupled with the first. As students gain experience as students, they become able to think about how they themselves learn best, and you (as the teacher) can encourage such self-reflection as one your goals for their learning. These changes allow you to transfer some of your responsibilities for arranging learning to the students themselves. For the biology student mentioned above, for example, you may be able not only to plan activities that support comparing species, but also to devise ways for the student to think about how he or she might learn the same information independently. The resulting self-assessment and self-direction of learning often goes by the name of metacognition—an ability to think about and regulate one’s own thinking (Israel, 2005). Metacognition can sometimes be difficult for students to achieve, but it is an important goal for social constructivist learning because it gradually frees learners from dependence on expert teachers to guide their learning. Reflective learners, you might say, become their own expert guides. Like with using Bloom’s taxonomy, though, promoting metacognition and self-directed learning is important enough that I will come back to it later in more detail (especially in Chapter 8: Instructional Strategies).

By assigning a more visible role to expert helpers—and by implication also to teachers—than does the psychological constructivism, social constructivism is seemingly more complete as a description of what teachers usually do in classrooms, and of what they usually hope students will experience there. As we will see in the next chapter, however, there are more uses to a theory than whether it describes the moment-to-moment interactions between teacher and students. As I explain there, some theories can be helpful for planning instruction rather than for doing it. It turns out that this is the case for psychological constructivism, which offers important ideas about the appropriate sequencing of learning and development. This fact makes the psychological constructivism valuable in its own way, even though it (and a few other learning theories as well) seem to “omit” mentioning teachers, parents, or experts in detail. So do not make up your mind about the relative merits of different learning theories yet!

Go Back to Introductory Section to Chapter 2...


text:
User talk:Iamgravity

Jamo stroke order
Hi, Iamgravity. An anonymous contributor said that some of the stroke orders in your jamo images are not standard. I'd like to figure out whether there really is a set standard stroke order. Do you remember where you found the orders for the jamo whose images you uploaded? Rodasmith 18:37, 9 August 2007 (UTC)

 * I made them from my own knowledge and did not have a reference book. Furthermore, I am left handed, so some might not be standard. I used the general guide, being "Stroke from top left to bottom right".  I will see if I can find the correct order. iamgravity 03:38, 22 September 2007 (UTC)

title: User talk:Iamgravity


text:
Devanagari

The Dēvanāgarī (देवनागरी) script is used to write many Indian and Nepalese languages such as Hindi, Konkani, Sanskrit, Marathi, Maithili, Bhojpuri and Nepali. It is a phonetic system, meaning in principle, one letter always represents the same sound, which is relatively convenient.

The consonants are followed by the vowel अ (schwa sound) by default, but this is not written out. The sign ् is used to indicate that a consonant is not followed by the default vowel. Consonants may be modified by each of the other vowels and in this case, the dependent form of the vowel is written.

There are two main difficulties:
 * 1) most consonants can be combined to form combinations.
 * 2) the vowels are written differently depending on their position in a word - whether they are in the beginning or not and whether they follow a vowel or another consonant.

With this in mind, please continue reading this wikibook, which aims to teach more about the Devanagari alphabet. Read more about Devanagari script from the resources given below.

Chapters

 * 1) /Overview/
 * 2) /Ligatures/
 * 3) /Numbers/
 * 4) /Alphabet/
 * 5) Vowels (स्वर)
 * 6) /Consonants/
 * 7) Exercises:
 * 8) /Lesson 1/
 * 9) /Lesson 2/

Devanagari Devanagari דוונגארי

title: Devanagari


text:
User:SPQRobin

See meta:User:SPQRobin

title: User:SPQRobin


text:
Metasploit/Support

=Support=

Subscribe
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The server will reply and ask you to confirm the request. You must reply to the email to confirm your subscription. ahly_com7@yahoo.com

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Sending the word "unsubscribe" to the framework[at]metasploit.com list just annoys the other 1400 people on the list ;-)

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The goal of the list is to create a place for detailed discussion about exploit development and the framework code. If you write your own modules or hack on the code in any shape, please subscribe.

Subscribe
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Sending the word "unsubscribe" to the framework[at]metasploit.com list just annoys the other 1400 people on the list ;-)

Metasploit official blog
Lots of tutorials and how-tos

title: Metasploit/Support


text:
User talk:125.236.44.51

 * [[Image:Octagon-warning.svg|left|30px]] You have been blocked from editing Wikibooks  as a result of your .  Please note that page blanking, addition of random text or spam, deliberate misinformation, privacy violations, personal attacks; and repeated, blatant violations of our neutral point of view policy are considered vandalism. If you wish to make useful contributions, you are welcome to come back after the block expires. --Az1568(Talk) 03:28, 10 August 2007 (UTC)

title: User talk:125.236.44.51


text:
Talk:Bartending/Cocktails/Martini

The assertion that bitters are are not part of the classic martini is tenuous. The Savoy Cocktail Book calls for 2 oz. gin, 1 oz. vermouth, and 2 dashes orange bitters.

title: Talk:Bartending/Cocktails/Martini


text:
More C++ Idioms/Non-throwing swap

= Non-throwing swap =

Intent

 * To implement an exception safe and efficient swap operation.
 * To provide uniform interface to it to facilitate generic programming.

Also Known As

 * Exception safe swap

Motivation
A typical implementation of swap could be given as follows: This can be problematic for two reasons:
 * Performance: Swapping of two large, complex objects of the same type is inefficient due to acquisition and release of resources for the intermediate temporary object.
 * Exception-safety: This generic swap implementation may throw if resources are not available. (Such a behavior does not make sense where in fact no new resources should have been requested in the first place.) Therefore, this implementation cannot be used for the Copy-and-swap idiom.

Solution and Sample Code
Non-throwing swap idiom uses Handle Body idiom to achieve the desired effect. The abstraction under consideration is split between two implementation classes. One is handle and other one is body. The handle holds a pointer to a body object. The swap is implemented as a simple swap of pointers, which are guaranted to not throw exceptions and it is very efficient as no new resources are acquired or released. Although an efficient and exception-safe swap function can be implemented (as shown above) as a member function, non-throwing swap idiom goes further than that for simplicity, consistency, and to facilitate generic programming. An explicit specialization of std::swap should be added in the std namespace as well as the namespace of the class itself. Adding it in two places takes care of two different common usage styles of swap (1) unqualified swap (2) fully qualified swap (e.g., std::swap). When unqualified swap is used, right swap is looked up using Koenig lookup (provided one is already defined). If fully qualified swap is used, Koenig lookup is suppressed and one in the std namespace is used instead. It is a very common practice. Remaining discussion here uses fully qualified swap only. It gives a uniform look and feel because C++ programmers often use swap function in an idiomatic way by fully qualifying it with std:: as shown below.

In such a case, the right, efficient implementation of swap is chosen when zoo is instantiated with String class defined earlier. Otherwise, the default std::swap function template would be instantiated -- completely defeating the purpose of defining the member swap and namespace scope swap function. This idiom of defining explicit specialization of swap in std namespace is particularly useful in generic programming.

Such uniformity in using non-throwing swap idiom leads to its cascading use as given in the example below.

Therefore, it is a good idea to define a specialization of std::swap for the types that are amenable to an exception safe, efficient swap implementation. The C++ standard does not currently allow us to add new templates to the std namespace, but it does allow us to specialize templates (e.g. std::swap) from that namespace and add them back in it.

Caveats
Using non-throwing swap idiom for template classes (e.g., Matrix) can be a subtle issue. As per the C++98 standard, only the full specialization of std::swap is allowed to be defined inside std namespace for the user-defined types. Partial specializations or function overloading is not allowed by the language. Trying to achieve the similar effect for template classes (e.g., Matrix) results into overloading of std::swap in std namespace, which is technically undefined behavior. This is not necessarily the ideal state of affairs as indicated by some people in a spectacularly long discussion thread on comp.lang.c++.moderated newsgroup. There are two possible solutions, both imperfect, to this issue:
 * 1) Standard-compliant solution. Leveraging on Koenig lookup, define an overloaded swap function template in the same namespace as that of the class being swapped. Not all compilers may support this correctly, but this solution is compliant to the standard.
 * 2) Fingers-crossed solution. Partially specialize std::swap and ignore the fact that this is technically undefined behavior, hoping that nothing will happen and wait for a fix in the next language standard.

Known Uses
All boost smart pointers (e.g., boost::shared_ptr)

Related Idioms

 * Copy-and-swap

title: More C++ Idioms/Non-throwing swap


text:
More C++ Idioms/Copy-and-swap

= Copy-and-swap =

Intent
To create an exception safe implementation of overloaded assignment operator.

Also Known As
Create-Temporary-and-Swap

Motivation
Exception safety is a very important cornerstone of highly reliable C++ software that uses exceptions to indicate "exceptional" conditions. There are at least 3 types of exception safety levels: basic, strong, and no-throw. Basic exception safety should be offered always as it is usually cheap to implement. Guaranteeing strong exception safety may not be possible in all the cases. The copy-and-swap idiom allows an assignment operator to be implemented elegantly with strong exception safety.

Solution and Sample Code
Create a temporary and swap idiom acquires new resource before it forfeits its current resource. To acquire the new resource, it uses RAII idiom. If the acquisition of the new resource is successful, it exchanges the resources using the non-throwing swap idiom. Finally, the old resource is released as a side effect of using RAII in the first step. Some variations of the above implementation are also possible. A check for self assignment is not strictly necessary but can give some performance improvements in (rarely occurring) self-assignment cases.

copy elision and copy-and-swap idiom

Strictly speaking, explicit creation of a temporary inside the assignment operator is not necessary. The parameter (right hand side) of the assignment operator can be passed-by-value to the function. The parameter itself serves as a temporary.

This is not just a matter of convenience but in fact an optimization. If the parameter (s) binds to an lvalue (another non-const object), a copy of the object is made automatically while creating the parameter (s). However, when s binds to an rvalue (temporary object, literal), the copy is typically elided, which saves a call to a copy constructor and a destructor. In the earlier version of the assignment operator where the parameter is accepted as const reference, copy elision does not happen when the reference binds to an rvalue. This results in an additional object being created and destroyed.

In C++11, such an assignment operator is known as a unifying assignment operator because it eliminates the need to write two different assignment operators: copy-assignment and move-assignment. As long as a class has a move-constructor, a C++11 compiler will always use it to optimize creation of a copy from another temporary (rvalue). Copy-elision is a comparable optimization in non-C++11 compilers to achieve the same effect.

Not every class benefits from this style of assignment operator. Consider a String assignment operator, which releases old memory and allocates new memory only if the existing memory is insufficient to hold a copy of the right hand side String object. To implement this optimization, one would have to write a custom assignment operator. Since a new String copy would nullify the memory allocation optimization, this custom assignment operator would have to avoid copying its argument to any temporary Strings, and in particular would need to accept its parameter by const reference.

Related Idioms

 * Resource Acquisition Is Initialization
 * Non-throwing swap

title: More C++ Idioms/Copy-and-swap


text:
More C++ Idioms/Shrink-to-fit

= Shrink-to-fit =

Intent
Minimize the capacity of a container just enough to hold existing range.

Also Known As
"Swap-To-Fit", introduced by Scott Meyers in his book "Effective STL".

Motivation
Standard library containers often allocate more memory than the actual number of elements in them. Such a policy results in an optimization of saving some allocations when a container grows in size. On the other hand, when size of the container reduces, there is often leftover capacity in the container. The leftover capacity of the container can be unnecessary wastage of memory resources. Shrink-to-fit idiom has been developed to reduce the extra capacity to a minimum required capacity and thereby saving memory resources.

Solution and Sample Code
Shrink-to-fit idiom is as simple as the one given below.

The first half of the statement,, creates a temporary vector of integers and it is guaranteed to allocate memory just enough to hold all the elements in the parameter,. The second half of the statement swaps the temporary vector with  using the non-throwing swap member function. is very efficient, amounting to little more than swapping pointers between the vectors. After swapping, the temporary goes out of scope and deletes the memory originally held by, whereas   retains the memory allocated by the temporary, so it has just enough to hold the original elements in.

, which may be implemented using reference counting, but also for, whose copy-constructor might copy the other vector's excess capacity ) is to use the "range constructor" instead of the copy constructor:

Solution in C++11
In C++11 some containers declare such idiom as function shrink_to_fit, e.g. vector, deque, basic_string. shrink_to_fit is a non-binding request to reduce capacity to size.

Related Idioms

 * Clear-and-minimize
 * Non-throwing swap

title: More C++ Idioms/Shrink-to-fit


text:
More C++ Idioms/Clear-and-minimize

= Clear-and-minimize =

Intent
Clear a container and minimize the capacity of the container.

Also Known As
This is sometimes called the swap with temporary idiom.

Motivation
Standard library containers often allocate more memory than the actual number of elements in them. Such a policy results in an optimization of saving some allocations when a container grows in size. On the other hand, when the size of the container reduces, there is often leftover capacity in the container. The leftover capacity of the container can be unnecessary wastage of memory resources. The clear-and-minimize idiom has been developed to clear a container and reduce the extra capacity to a minimum of zero, thereby saving memory.

Solution and Sample Code
Implementing the Clear-and-minimize idiom is as simple as the one given below.

The first half of the statement,, creates a temporary   guaranteed to allocate either zero raw memory or an implementation minimum. The second half of the statement swaps the temporary with  using the Non-throwing swap idiom, which is efficient. After swapping, the temporary created by the compiler goes out of scope and the chunk of memory originally held by  is released.

Solution in C++11
Since C++11, some containers declare the function, like vector, deque and basic_string. is a non-binding request to reduce  to. Thus, using  and   is a non-binding request to clear-and-minimize.

Related Idioms

 * Shrink-to-fit
 * Non-throwing swap

title: More C++ Idioms/Clear-and-minimize


text:
More C++ Idioms/Counted Body

= Counted Body/Reference Counting (intrusive) =

Intent
Manage logical sharing of a resource/object, prevent expensive copying, and allow proper resource deallocation of objects that use dynamically allocated resources.

Also Known As

 * Reference Counting (intrusive)
 * Counted Body

Motivation
When Handle/Body idiom is used, quite often it is noticed that copying of bodies is expensive. This is because copying of bodies involves allocation of memory and copy construction. Copying can be avoided by using pointers and references, but these leave the problem of who is responsible for cleaning up the object. Some handle must be responsible for releasing memory resources allocated for the body. Usually it is the last one. Without automatic reclamation of memory resources, it leaves a user-visible distinction between built-in types and user-defined types.

Solution and Sample Code
The solution is to add a reference count to the body class to facilitate memory management; hence the name "Counted Body." Memory management is added to the handle class, particularly to its implementation of initialization, assignment, copying, and destruction. Gratuitous copying is avoided, leading to a more efficient implementation. This idiom presumes that the programmer can edit the source code for the body. When that's not possible, use Detached Counted Body. When counter is stored inside body class, it is called intrusive reference counting and when the counter is stored external to the body class it is known as non-intrusive reference counting. This implementation is a variation of shallow copy with the semantics of deep copy and the efficiency of Smalltalk name-value pairs.

The output should be as below:

Consequences
Creation of multiple reference counts will result into multiple deletion of the same body, which is undefined. Care must be taken to avoid creating multiple reference counts to the same body. Intrusive reference counting easily supports it. With non-intrusive reference counting, programmer discipline is required to prevent duplicate reference counts.

Known Uses

 * boost::shared_ptr (non-intrusive reference counting)
 * boost::intrusive_ptr (intrusive reference counting)
 * std::shared_ptr
 * the Qt toolkit, e.g. QString

Related Idioms

 * Handle Body
 * Detached Counted Body (non-intrusive reference counting)
 * Smart Pointer
 * Copy-and-swap

title: More C++ Idioms/Counted Body


text:
More C++ Idioms/Handle Body Hierarchy

Also Known As
The Body

title: More C++ Idioms/Handle Body Hierarchy


text:
More C++ Idioms/Concrete Data Type

= Concrete Data Type =

Intent
To control object's scope and lifetime by allowing or disallowing dynamic allocation using the free store (heap)

Motivation
C++ provides two ways of controlling lifetime of an object and binding it with a program level identifier (variable). First is a scoped variable and an object, which are destroyed immediately after the scope ends (e.g., function scope integers). Second is a scoped variable (often a pointer) and a dynamically allocated object in the free store. In this case, at the end of the scope of the variable, the variable ceases to exist but the object's lifetime continues (e.g., singletons, a window object). It is possible to force the choice of the lifetime of an object either first way or the second using the Concrete Data Type idiom.

Solution and Sample Code
This idiom simply uses class level access modifiers (private, protected) to achieve the goal. The following code shows how a MouseEventHandler class forces dynamic allocation.

Another way to force dynamic allocation is to prevent direct access to the constructor and instead provide a static function instance to return a dynamically allocated object. It is in many ways similar to the Singleton design pattern. Moreover, it is not strictly necessary to use polymorphic delete to reclaim memory. A member function destroy can serve the purpose saving the space required for a v-table pointer.

An opposite extreme of this idiom is to force scoped variable (a.k.a. automatic variable) only. It can be achieved using a private new operator.

ScopedLock object can't be allocated dynamically with standard uses of new operator, nothrow new, and the placement new.

title: More C++ Idioms/Concrete Data Type


text:
More C++ Idioms/Algebraic Hierarchy

= Algebraic Hierarchy =

Intent
To hide multiple closely related algebraic abstractions (numbers) behind a single generic abstraction and provide a generic interface to it.

Also Known As

 * State (Gamma et al.)

Motivation
In pure object-oriented languages like Smalltalk, variables are run-time bindings to objects that act like labels. Binding a variable to an object is like sticking a label on it. Assignment in these languages is analogous to peeling a label off one object and putting it on another. On the other hand, in C and C++, variables are synonyms for addresses or offsets instead of being labels for objects. Assignment does not mean re-labelling, it means overwriting old contents with new one. Algebraic Hierarchy idiom uses delegated polymorphism to simulate weak variable to object binding in C++. Algebraic Hierarchy uses the Envelope Letter idiom in its implementation. The motivation behind this idiom is to be able to write code like this:

Solution and Sample Code
Complete code showing an implementation of the Algebraic Hierarchy idiom:

Related Idioms

 * Handle Body
 * Envelope Letter

title: More C++ Idioms/Algebraic Hierarchy


text: More C++ Idioms/Promotion Ladder

title: More C++ Idioms/Promotion Ladder


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Template talk:Biology bookshelf

The entry for Botany appears in duplicate -- could an admin please correct it? 192.223.158.62 09:39, 10 August 2007 (UTC)

 * Done & thanks -- Herby talk thyme 09:43, 10 August 2007 (UTC)

title: Template talk:Biology bookshelf


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Latin/Lesson 10-Idioms

 * ad unum-to a man
 * aequo animo-contentedly, resignedly, patiently
 * aere alieno premi-to be heavily in debt
 * agere gratias-to thank
 * alius aliam in partem-one in one direction, another in another
 * amico aliquo uti-to be on terms of intimacy with some one
 * animo tenus commoveri-to be moved to the heart
 * ad astra-to the stars

title: Latin/Lesson 10-Idioms


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User:Cometstyles

 Meta | Wikipedia | Quote | Commons | Simple | Wikia  Wiktionary | Books | Source | Species | News | MediaWiki | Incubator | Test

title: User:Cometstyles


text: User:Reece/Main Page Archive/Featured books


text:
PBASIC Programming/Print Version

= GNU Free Documentation License =

title: PBASIC Programming/Print Version


text: User:Reece/Main Page Archive/Bookshelves


text:
Contemporary Educational Psychology/Chapter 3: Student Development/Cognitive Development: The Theory of Jean Piaget

Cognitive Development: The Theory of Jean Piaget
Cognition refers to thinking and memory processes, and cognitive development' refers to long-term changes in these processes. While cognition has been studied from several different perspectives and in the light of several theories, the one that is both the most widely known among educators and the most frankly “developmental” is the cognitive stage theory of a Swiss psychologist named Jean Piaget. Piaget created and studied an account of how children and youth gradually become able to think logically and scientifically. This section of Chapter 3 focuses exclusively on Piaget’s ideas. Other cognitive perspectives and research—the ones that are not as fully “developmental”—are discussed in later chapters, especially Chapter 8: Instructional Strategies.

Remember my brief comments in Chapter 2 about how Piaget explained learning? There, I described Piaget as a psychological constructivist: in his view, learning proceeded by the interplay of assimilation (adjusting new experiences to fit prior concepts) and accommodation (adjusting concepts to fit new experiences). The to-and-fro of these two processes leads not only to short-term learning, as I pointed out in Chapter 2, but also to long-term developmental change. The long-term developments are really the main focus of Piaget’s cognitive theory.

Because of close observation of his own three children, and later of other children and youth, Piaget proposed that cognition developed through distinct stages from birth through the end of adolescence. By stages he meant a sequence of thinking patterns with four key features: 1) they always happened in the same order, 2) no stage was ever skipped, and 3) each stage was a significant transformation of the stage before it, and 4) each later stage incorporated the earlier stages into itself. Basically this is the “staircase” model of development that I mentioned at the beginning of this chapter. Piaget proposed four major stages of cognitive development, and called them 1) sensorimotor intelligence, 2) preoperational thinking, 3) concrete operational thinking, and 4) formal operational thinking. Each stage is correlated with a particular age period of childhood or adolescence, though only rather approximately.

The Sensorimotor Stage: Birth to Age 2
In Piaget’s theory, the sensorimotor stage comes first, and is defined as the time when infants “think” mainly through their senses and motor actions. As every new parent will attest, infants touch, manipulate, look, listen to, and even bite and chew objects. These actions allow them to learn about the world and are crucial to their early cognitive development.

The infant’s actions allow the child to represent (or construct simple concepts of ) objects and events. A toy animal may be just a confusing array of sensations at first, but by acting on it repeatedly, the child gradually organizes the sensations and actions into a stable concept, toy animal. The representation acquires a permanence lacking in the individual experiences of the object; because of it, the child “knows,” or at least believes, that toy animal exists even if the actual toy animal is temporarily out of sight. Piaget called this sense of stability object permanence, a belief that objects exist whether or not they are experienced currently. It is a major achievement of sensorimotor development, and marks a qualitative transformation in how older infants (24 months) think about experience compared to younger infants (6 months).

During much of infancy, of course, a child can only barely talk, so a lot of sensorimotor development happens without the support of language. It might therefore seem hard to learn what infants are thinking, but Piaget devised several simple, but clever experiments to get around their lack of language, and that suggest that infants do indeed represent objects even without being able to talk (Piaget, 1952). In one, for example, he showed that hiding an object (like a toy animal) under a blanket consistently prompts an older infant (18–24 months) to search for the object, but fails to prompt a younger infant (less than six months) to do so. (You can try this too if you happen to have access to young infant.) “Something” motivates the search by the older infant even without the benefit of much language, and presumably the “something” is a permanent concept or representation of the object.

The Preoperational Stage: Age 2 to 7
In the preoperational stage, children use their new ability to represent objects in a wide variety of activities, but they do not yet do it in organized, fully logical ways. One of the most obvious examples of this phase of cognition is dramatic play, the improvised make-believe of preschool children. If you have ever had responsibility for preschool children, you have very likely witnessed dramatic play. Ashley holds a plastic banana to her ear and says, “Hello, Mom? Can you be sure to bring me my baby doll? OK!” Then she hangs up the banana and pours tea for Jeremy into an invisible cup. Jeremy, who has been watching, giggles at the sight of all of this, and exclaims, “Ringing! Oh Ashley, the phone is ringing again! You better answer it.” And so on.

In a way, children immersed in make-believe behave like the mentally insane, in that they do not think realistically. But they are not truly insane because they have not taken leave of their senses completely. At some level, Ashley and Jeremy both know that the banana is still a banana and not really a telephone; they are merely representing it as a telephone. They are thinking on two levels at once—one imaginative and the other realistic. This dual processing of experience makes dramatic play an early example of metacognition, or reflecting on and monitoring thinking itself. As I explained in Chapter 2, metacognition is a highly desirable skill for success in school, one that teachers often encourage (Bredekamp & Copple, 1997; Paley, 2005). Partly for this reason, teachers of young children (in preschool, kindergarten and even into first or second grade) often make time and space in their classrooms for dramatic play, and may even get involved in it on the sidelines in an effort to extend the play further.

The Concrete Operational Stage: Age 7 to 11
As children continue in elementary school, they become able to represent ideas and events more flexibly and logically. The rules of their thinking may seem very basic by adult standards and usually operate unconsciously, but nonetheless they allow children to solve problems more systematically than before, and therefore to be successful with many academic tasks. In the concrete operational stage, for example, a child may unconsciously follow the rule that “if nothing is added or taken away, then the amount of something stays the same.” This simple principle helps in understanding certain arithmetic tasks, such as in adding or subtracting zero from a number, as well as in understanding certain classroom science experiments, such as ones involving judgments of the amounts of liquids when mixed. Piaget called this period the concrete operational stage because children mentally “operate” on concrete objects and events. They are not yet able, however, to operate (or think) systematically about representations of objects or events. Manipulating representations is a more abstract skill that does not develop until later, during adolescence.

Concrete operational thinking differs from preoperational thinking in two important ways, each of which makes children more skilled as students. One difference is reversibility, or the ability to think about the steps of a process in any order. Imagine a simple science experiment, for example, such as one to explore which of several objects sink and which ones float. Both the preoperational and concrete operational child can recall and describe the steps in this experiment, but only the concrete operational child can recall them in any order. This skill is very helpful on any number of classroom tasks involving multiple steps. In teaching new vocabulary from a story, for example, a teacher might tell students to “first make a list of words in the story that you do not know, then find and write down their definitions, and finally then get a friend to test you on your list.” These directions involve repeatedly remembering to move back and forth between a second step and a first—a task that concrete operational students—and most adults—find easy, but that preoperational children often forget to do or find confusing. If the latter children are to do this task reliably, they may need external prompts, such as having the teacher remind them periodically to go back to the story to look for more unknown words.

The other new feature of thinking during the concrete operational stage is the child’s ability to decenter, or focus on more than one feature of a problem or task at a time. There are hints of decentration in preschool children’s dramatic play, which requires being aware on two levels at once—knowing that a banana can be both a banana and a “telephone.” But the decentration of the concrete operational stage is more deliberate and conscious than preschoolers’ make-believe. Now the child can attend to two things at once quite purposely. Suppose you give students a sheet with a mixture of subtraction problems on it, and ask them to do this: “Find all of the problems that involve two-digit subtraction and involve ‘borrowing’ from the next column. Circle and solve only those problems.” Following these instructions is quite possible for a concrete operational student (as long as they have been listening to you!) because the student can attend to the two subtasks simultaneously—finding the two-digit problems and identifying which of them actually involve borrowing. (Whether the student actually knows how to “borrow,” however, or only how to identify examples of such problems, is a separate question.)

In real classroom tasks, reversibility and decentration often happen together. A well-known example of joint presence is Piaget’s experiments with conservation, the belief that an amount or quantity stays the same even if it changes apparent size or shape (Piaget, 2001; Matthews, 1998). Imagine two identical balls made of clay. Any child, whether preoperational or concrete operational, will agree that the two indeed have the same amount of clay in them. But if you now squish one of the balls into a long, thin “hot dog,” the preoperational child is likely to say that the amount of that ball has changed—either because it is longer or because it is thinner, but at any rate because it is now different. The concrete operational child will not make this mistake, thanks to new cognitive skills of reversibility and decentration: for him or her, the amount is the same because “you could squish it back into a ball again” (reversibility) and because “it may be longer, but it is also thinner” (decentration). Piaget would say the concrete operational child “has conservation of quantity.”

In a sense the classroom examples that I described above also involve reversibility and decentration jointly. As already mentioned, the vocabulary activity requires reversibility (going back and forth between identifying words and looking up their meanings); but it can also be construed as an example of decentration (keeping in mind two tasks at once—word identification and dictionary search). And as mentioned, the arithmetic activity requires decentration (looking for problems that meet two criteria and also solving them), but it can also be construed as an example of reversibility (going back and forth between subtasks, as with the vocabulary activity). Either way, the development of concrete operational skills can support students in many basic academic tasks.

The Formal Operational Stage: Age 11 and Beyond
The last of the Piagetian stages resembles the concrete operational stage, except that the young person becomes able to reason not only about tangible objects and events, but also about hypothetical or abstract ones. Hence it has the name formal operational stage—the period when the individual can “operate” on “forms” or representations. With students at this level, the teacher can pose hypothetical (or contrary-to-fact) problems: “What if the George Washington had lost the American Revolutionary War?” or “What if the first white explorers had settled first in California instead of on the East Coast of North America?” To answer these questions, students must use hypothetical reasoning, meaning that they must manipulate information that varies in several ways at once, and do so entirely in their minds.

Piaget was primarily concerned with hypothetical reasoning about scientific problems, and his studies of formal operational thinking therefore often look a lot like problems that middle- or high-school teachers might pose in a science class. In one, for example, a young person is presented with a simple pendulum, to which different amounts of weight can be hung (Inhelder & Piaget, 1958). The experimenter asks, “What determines how fast the pendulum swings: the length of the string holding it, the weight attached to it, or the distance that it is pulled to the side?” The young person is not allowed to solve this problem by trial-and-error with the materials themselves, but must reason a way to the solution mentally. To do so systematically, he or she must imagine that varying each factor separately, while imagining the other factors are held constant. This kind of thinking requires facility at manipulating the relevant objects and actions mentally—precisely what formal operations are about.

As you might imagine, students with an ability to think hypothetically have an advantage in doing certain kinds of school work: by definition, they require relatively few “props” to solve problems. In this sense they can, in principle, be more self-directed than students who rely only on concrete operations—certainly a desirable quality in the opinion of most teachers. Note, though, that although formal operational thinking may be desirable, it is not sufficient for school success, and it is far from being the only way that students achieve educational success. Being capable of formal or hypothetical thinking does not insure that a student is motivated or well-behaved, for example, nor does it mean that a student also has other desirable skills or qualities, such as ability at sports, music, or art. The fourth stage in Piaget’s theory is really about a particular kind of formal thinking, the kind needed to solve scientific problems and devise scientific experiments. Since many people do not normally deal with these sorts of problems in the normal course of their lives, it should be no surprise that research finds that many people never achieve or use formal thinking fully or consistently, or that they use it only in selected areas with which they are very familiar (Case & Okomato, 1996).

Social Development: Relationships and Personal Motives
Social development refers to the long-term changes in relationships and interactions involving self, peers, and family. It includes both positive changes, such as how friendships develop, and negative changes, such as aggression or bullying. (read more...)