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Claude Shannon

Claude Elwood Shannon (April 30, 1916 – February 24, 2001) was an American mathematician, electrical engineer, computer scientist and cryptographer known as the "father of information theory" and as the "father of the Information Age". Shannon was the first to describe the Boolean gates (electronic circuits) that are essential to all digital electronic circuits, and was one of the founding fathers of artificial intelligence. He is credited alongside George Boole for laying the foundations of the Information Age.

At the University of Michigan, Shannon dual degreed, graduating with a Bachelor of Science in both electrical engineering and mathematics in 1936. A 21-year-old master's degree student at the Massachusetts Institute of Technology (MIT) in electrical engineering, his thesis concerned switching circuit theory, demonstrating that electrical applications of Boolean algebra could construct any logical numerical relationship, thereby establishing the theory behind digital computing and digital circuits. The thesis has been claimed to be the most important master's thesis of all time, as in 1985, Howard Gardner described it as "possibly the most important, and also the most famous, master's thesis of the century", while Herman Goldstine described it as "surely... one of the most important master's theses ever written... It helped to change digital circuit design from an art to a science." He then graduated with a PhD in mathematics from MIT in 1940.

Shannon contributed to the field of cryptanalysis for national defense of the United States during World War II, including his fundamental work on codebreaking and secure telecommunications, writing a paper which is considered one of the foundational pieces of modern cryptography, with his work described as "a turning point, and marked the closure of classical cryptography and the beginning of modern cryptography." The work of Shannon is the foundation of secret-key cryptography, including the work of Horst Feistel, the Data Encryption Standard (DES), and much more. As a result, Shannon has been called the "founding father of modern cryptography".

His mathematical theory of communication laid the foundations for the field of information theory, with his famous paper being called the "Magna Carta of the Information Age" by Scientific American, along with his work being described as being at "the heart of today's digital information technology". Robert G. Gallager referred to the paper as a "blueprint for the digital era". Regarding the influence that Shannon had on the digital age, Solomon W. Golomb remarked "It's like saying how much influence the inventor of the alphabet has had on literature." Shannon's theory is widely used and has been fundamental to the success of many scientific endeavors, such as the invention of the compact disc, the development of the Internet, feasibility of mobile phones, the understanding of black holes, and more, and is at the intersection of numerous important fields.

Shannon made numerous contributions to the field of artificial intelligence, writing papers on programming a computer for chess, which have been immensely influential, and also his Theseus machine was the first electrical device to learn by trial and error, being one of the first examples of artificial intelligence. He also co-organized and participated in the Dartmouth workshop of 1956, considered the founding event of the field of artificial intelligence.

Rodney Brooks declared that Shannon was the 20th century engineer who contributed the most to 21st century technologies. Shannon's achievements are considered to be on par, in his field, with those of Albert Einstein and Sir Isaac Newton in theirs.

Childhood
The Shannon family lived in Gaylord, Michigan, and Claude was born in a hospital in nearby Petoskey. His father, Claude Sr. (1862–1934), was a businessman and, for a while, a judge of probate in Gaylord. His mother, Mabel Wolf Shannon (1880–1945), was a language teacher, who also served as the principal of Gaylord High School. Claude Sr. was a descendant of New Jersey settlers, while Mabel was a child of German immigrants. Shannon's family was active in their Methodist Church during his youth.

Most of the first 16 years of Shannon's life were spent in Gaylord, where he attended public school, graduating from Gaylord High School in 1932. Shannon showed an inclination towards mechanical and electrical things. His best subjects were science and mathematics. At home, he constructed such devices as models of planes, a radio-controlled model boat and a barbed-wire telegraph system to a friend's house a half-mile away. While growing up, he also worked as a messenger for the Western Union company.

Shannon's childhood hero was Thomas Edison, whom he later learned was a distant cousin. Both Shannon and Edison were descendants of John Ogden (1609–1682), a colonial leader and an ancestor of many distinguished people.

Logic circuits
In 1932, Shannon entered the University of Michigan, where he was introduced to the work of George Boole. He graduated in 1936 with two bachelor's degrees: one in electrical engineering and the other in mathematics.

In 1936, Shannon began his graduate studies in electrical engineering at the Massachusetts Institute of Technology (MIT), where he worked on Vannevar Bush's differential analyzer, which was an early analog computer that was composed of electromechanical parts and could solve differential equations. While studying the complicated ad hoc circuits of this analyzer, Shannon designed switching circuits based on Boole's concepts. In 1937, he wrote his master's degree thesis, A Symbolic Analysis of Relay and Switching Circuits, with a paper from this thesis published in 1938. A revolutionary work for switching circuit theory, Shannon diagramed switching circuits that could implement the essential operators of Boolean algebra. Then he proved that his switching circuits could be used to simplify the arrangement of the electromechanical relays that were used during that time in telephone call routing switches. Next, he expanded this concept, proving that these circuits could solve all problems that Boolean algebra could solve. In the last chapter, he presented diagrams of several circuits, including a digital 4-bit full adder.

Using electrical switches to implement logic is the fundamental concept that underlies all electronic digital computers. Shannon's work became the foundation of digital circuit design, as it became widely known in the electrical engineering community during and after World War II. The theoretical rigor of Shannon's work superseded the ad hoc methods that had prevailed previously. Howard Gardner hailed Shannon's thesis "possibly the most important, and also the most noted, master's thesis of the century."

Shannon received his PhD in mathematics from MIT in 1940. Vannevar Bush had suggested that Shannon should work on his dissertation at the Cold Spring Harbor Laboratory, in order to develop a mathematical formulation for Mendelian genetics. This research resulted in Shannon's PhD thesis, called An Algebra for Theoretical Genetics.

In 1940, Shannon became a National Research Fellow at the Institute for Advanced Study in Princeton, New Jersey. In Princeton, Shannon had the opportunity to discuss his ideas with influential scientists and mathematicians such as Hermann Weyl and John von Neumann, and he also had occasional encounters with Albert Einstein and Kurt Gödel. Shannon worked freely across disciplines, and this ability may have contributed to his later development of mathematical information theory.

Wartime research
Shannon had worked at Bell Labs for a few months in the summer of 1937, and returned there to work on fire-control systems and cryptography during World War II, under a contract with section D-2 (Control Systems section) of the National Defense Research Committee (NDRC).

Shannon is credited with the invention of signal-flow graphs, in 1942. He discovered the topological gain formula while investigating the functional operation of an analog computer.

For two months early in 1943, Shannon came into contact with the leading British mathematician Alan Turing. Turing had been posted to Washington to share with the U.S. Navy's cryptanalytic service the methods used by the British Government Code and Cypher School at Bletchley Park to break the cyphers used by the Kriegsmarine U-boats in the north Atlantic Ocean. He was also interested in the encipherment of speech and to this end spent time at Bell Labs. Shannon and Turing met at teatime in the cafeteria. Turing showed Shannon his 1936 paper that defined what is now known as the "universal Turing machine". This impressed Shannon, as many of its ideas complemented his own.

In 1945, as the war was coming to an end, the NDRC was issuing a summary of technical reports as a last step prior to its eventual closing down. Inside the volume on fire control, a special essay titled Data Smoothing and Prediction in Fire-Control Systems, coauthored by Shannon, Ralph Beebe Blackman, and Hendrik Wade Bode, formally treated the problem of smoothing the data in fire-control by analogy with "the problem of separating a signal from interfering noise in communications systems." In other words, it modeled the problem in terms of data and signal processing and thus heralded the coming of the Information Age.

Shannon's work on cryptography was even more closely related to his later publications on communication theory. At the close of the war, he prepared a classified memorandum for Bell Telephone Labs entitled "A Mathematical Theory of Cryptography", dated September 1945. A declassified version of this paper was published in 1949 as "Communication Theory of Secrecy Systems" in the Bell System Technical Journal. This paper incorporated many of the concepts and mathematical formulations that also appeared in his A Mathematical Theory of Communication. Shannon said that his wartime insights into communication theory and cryptography developed simultaneously, and that "they were so close together you couldn't separate them". In a footnote near the beginning of the classified report, Shannon announced his intention to "develop these results … in a forthcoming memorandum on the transmission of information."

While he was at Bell Labs, Shannon proved that the cryptographic one-time pad is unbreakable in his classified research that was later published in 1949. The same article also proved that any unbreakable system must have essentially the same characteristics as the one-time pad: the key must be truly random, as large as the plaintext, never reused in whole or part, and kept secret.

Information theory
In 1948, the promised memorandum appeared as "A Mathematical Theory of Communication", an article in two parts in the July and October issues of the Bell System Technical Journal. This work focuses on the problem of how best to encode the message a sender wants to transmit. Shannon developed information entropy as a measure of the information content in a message, which is a measure of uncertainty reduced by the message. In so doing, he essentially invented the field of information theory.

The book The Mathematical Theory of Communication reprints Shannon's 1948 article and Warren Weaver's popularization of it, which is accessible to the non-specialist. Weaver pointed out that the word "information" in communication theory is not related to what you do say, but to what you could say. That is, information is a measure of one's freedom of choice when one selects a message. Shannon's concepts were also popularized, subject to his own proofreading, in John Robinson Pierce's Symbols, Signals, and Noise.

Information theory's fundamental contribution to natural language processing and computational linguistics was further established in 1951, in his article "Prediction and Entropy of Printed English", showing upper and lower bounds of entropy on the statistics of English – giving a statistical foundation to language analysis. In addition, he proved that treating space as the 27th letter of the alphabet actually lowers uncertainty in written language, providing a clear quantifiable link between cultural practice and probabilistic cognition.

Another notable paper published in 1949 is "Communication Theory of Secrecy Systems", a declassified version of his wartime work on the mathematical theory of cryptography, in which he proved that all theoretically unbreakable cyphers must have the same requirements as the one-time pad. He is credited with the introduction of sampling theorem, which he had derived as early as 1940, and which is concerned with representing a continuous-time signal from a (uniform) discrete set of samples. This theory was essential in enabling telecommunications to move from analog to digital transmissions systems in the 1960s and later.

Artificial Intelligence
In 1950, Shannon, designed, and built with the help of his wife, a machine learning device, Theseus. It consisted of a maze on a surface, below which were sensors that followed the path of a mechanical mouse through the maze. After much trial and error, this device would learn the shortest path through the maze, and direct the mechanical mouse through the maze. The pattern of the maze could be changed at will.

Mazin Gilbert says Theseus "inspired the whole field of AI. This random trial and error is the foundation of artificial intelligence."

Teaching at MIT
In 1956 Shannon joined the MIT faculty, holding an endowed chair. He worked in the Research Laboratory of Electronics (RLE). He continued to serve on the MIT faculty until 1978.

Later life
Shannon developed Alzheimer's disease and spent the last few years of his life in a nursing home; he died in 2001, survived by his wife, a son and daughter, and two granddaughters.

Hobbies and inventions

Outside of Shannon's academic pursuits, he was interested in juggling, unicycling, and chess. He also invented many devices, including a Roman numeral computer called THROBAC, and juggling machines. He built a device that could solve the Rubik's Cube puzzle.

Shannon designed the Minivac 601, a digital computer trainer to teach business people about how computers functioned. It was sold by the Scientific Development Corp starting in 1961.

He is also considered the co-inventor of the first wearable computer along with Edward O. Thorp. The device was used to improve the odds when playing roulette.

Personal life
Shannon married Norma Levor, a wealthy, Jewish, left-wing intellectual in January 1940. The marriage ended in divorce after about a year. Levor later married Ben Barzman.

Shannon met his second wife, Mary Elizabeth Moore (Betty), when she was a numerical analyst at Bell Labs. They were married in 1949. Betty assisted Claude in building some of his most famous inventions. They had three children.

Shannon presented himself as apolitical and an atheist.

Tributes
There are six statues of Shannon sculpted by Eugene Daub: one at the University of Michigan; one at MIT in the Laboratory for Information and Decision Systems; one in Gaylord, Michigan; one at the University of California, San Diego; one at Bell Labs; and another at AT&T Shannon Labs. The statue in Gaylord is located in the Claude Shannon Memorial Park. After the breakup of the Bell System, the part of Bell Labs that remained with AT&T Corporation was named Shannon Labs in his honor.

According to Neil Sloane, an AT&T Fellow who co-edited Shannon's large collection of papers in 1993, the perspective introduced by Shannon's communication theory (now called information theory) is the foundation of the digital revolution, and every device containing a microprocessor or microcontroller is a conceptual descendant of Shannon's publication in 1948: "He's one of the great men of the century. Without him, none of the things we know today would exist. The whole digital revolution started with him." The cryptocurrency unit shannon (a synonym for gwei) is named after him.

Shannon is credited by many as single-handedly creating information theory and for laying the foundations for the Digital Age.

A Mind at Play, a biography of Shannon written by Jimmy Soni and Rob Goodman, was published in 2017. They described Shannon as "the most important genius you’ve never heard of, a man whose intellect was on par with Albert Einstein and Isaac Newton".

On April 30, 2016, Shannon was honored with a Google Doodle to celebrate his life on what would have been his 100th birthday.

The Bit Player, a feature film about Shannon directed by Mark Levinson premiered at the World Science Festival in 2019. Drawn from interviews conducted with Shannon in his house in the 1980s, the film was released on Amazon Prime in August 2020.

Weaver's Contribution
Shannon's The Mathematical Theory of Communication, begins with an interpretation of his own work by Warren Weaver. Although Shannon's entire work is about communication itself, Warren Weaver communicated his ideas in such a way that those not acclimated to complex theory and mathematics could comprehend the fundamental laws he put forth. The coupling of their unique communicational abilities and ideas generated the Shannon-Weaver model, although the mathematical and theoretical underpinnings emanate entirely from Shannon's work after Weaver's introduction. For the layman, Weaver's introduction better communicates The Mathematical Theory of Communication, but Shannon's subsequent logic, mathematics, and expressive precision was responsible for defining the problem itself.

Shannon's mouse
"Theseus", created in 1950, was a mechanical mouse controlled by an electromechanical relay circuit that enabled it to move around a labyrinth of 25 squares. The maze configuration was flexible and it could be modified arbitrarily by rearranging movable partitions. The mouse was designed to search through the corridors until it found the target. Having travelled through the maze, the mouse could then be placed anywhere it had been before, and because of its prior experience it could go directly to the target. If placed in unfamiliar territory, it was programmed to search until it reached a known location and then it would proceed to the target, adding the new knowledge to its memory and learning new behavior. Shannon's mouse appears to have been the first artificial learning device of its kind.

Shannon's estimate for the complexity of chess
In 1949 Shannon completed a paper (published in March 1950) which estimates the game-tree complexity of chess, which is approximately 10120. This number is now often referred to as the "Shannon number", and is still regarded today as an accurate estimate of the game's complexity. The number is often cited as one of the barriers to solving the game of chess using an exhaustive analysis (i.e. brute force analysis).

Shannon's computer chess program
On March 9, 1949, Shannon presented a paper called "Programming a Computer for playing Chess". The paper was presented at the National Institute for Radio Engineers Convention in New York. He described how to program a computer to play chess based on position scoring and move selection. He proposed basic strategies for restricting the number of possibilities to be considered in a game of chess. In March 1950 it was published in Philosophical Magazine, and is considered one of the first articles published on the topic of programming a computer for playing chess, and using a computer to solve the game.

His process for having the computer decide on which move to make was a minimax procedure, based on an evaluation function of a given chess position. Shannon gave a rough example of an evaluation function in which the value of the black position was subtracted from that of the white position. Material was counted according to the usual chess piece relative value (1 point for a pawn, 3 points for a knight or bishop, 5 points for a rook, and 9 points for a queen). He considered some positional factors, subtracting ½ point for each doubled pawn, backward pawn, and isolated pawn; mobility was incorporated by adding 0.1 point for each legal move available.

Shannon's maxim
Shannon formulated a version of Kerckhoffs' principle as "The enemy knows the system". In this form it is known as "Shannon's maxim".

Shannon centenary
The Shannon centenary, 2016, marked the life and influence of Claude Elwood Shannon on the hundredth anniversary of his birth on April 30, 1916. It was inspired in part by the Alan Turing Year. An ad hoc committee of the IEEE Information Theory Society including Christina Fragouli, Rüdiger Urbanke, Michelle Effros, Lav Varshney and Sergio Verdú, coordinated worldwide events. The initiative was announced in the History Panel at the 2015 IEEE Information Theory Workshop Jerusalem and the IEEE Information Theory Society newsletter.

A detailed listing of confirmed events was available on the website of the IEEE Information Theory Society.

Some of the planned activities included:
 * Bell Labs hosted the First Shannon Conference on the Future of the Information Age on April 28–29, 2016, in Murray Hill, New Jersey, to celebrate Claude Shannon and the continued impact of his legacy on society. The event includes keynote speeches by global luminaries and visionaries of the information age who will explore the impact of information theory on society and our digital future, informal recollections, and leading technical presentations on subsequent related work in other areas such as bioinformatics, economic systems, and social networks. There is also a student competition
 * Bell Labs launched a Web exhibit on April 30, 2016, chronicling Shannon's hiring at Bell Labs (under an NDRC contract with US Government), his subsequent work there from 1942 through 1957, and details of Mathematics Department. The exhibit also displayed bios of colleagues and managers during his tenure, as well as original versions of some of the technical memoranda which subsequently became well known in published form.
 * The Republic of Macedonia is planning a commemorative stamp. A USPS commemorative stamp is being proposed, with an active petition.
 * A documentary on Claude Shannon and on the impact of information theory, The Bit Player, is being produced by Sergio Verdú and Mark Levinson.
 * A trans-Atlantic celebration of both George Boole's bicentenary and Claude Shannon's centenary that is being led by University College Cork and the Massachusetts Institute of Technology. A first event was a workshop in Cork, When Boole Meets Shannon, and will continue with exhibits at the Boston Museum of Science and at the MIT Museum.
 * Many organizations around the world are holding observance events, including the Boston Museum of Science, the Heinz-Nixdorf Museum, the Institute for Advanced Study, Technische Universität Berlin, University of South Australia (UniSA), Unicamp (Universidade Estadual de Campinas), University of Toronto, Chinese University of Hong Kong, Cairo University, Telecom ParisTech, National Technical University of Athens, Indian Institute of Science, Indian Institute of Technology Bombay, Indian Institute of Technology Kanpur, Nanyang Technological University of Singapore, University of Maryland, University of Illinois at Chicago, École Polytechnique Federale de Lausanne, The Pennsylvania State University (Penn State), University of California Los Angeles, Massachusetts Institute of Technology, Chongqing University of Posts and Telecommunications, and University of Illinois at Urbana-Champaign.
 * A logo that appears on this page was crowdsourced on Crowdspring.
 * The Math Encounters presentation of May 4, 2016, at the National Museum of Mathematics in New York, titled Saving Face: Information Tricks for Love and Life, focused on Shannon's work in information theory. A video recording and other material are available.

Awards and honors list
The Claude E. Shannon Award was established in his honor; he was also its first recipient, in 1972.

 * Stuart Ballantine Medal of the Franklin Institute, 1955
 * Member of the American Academy of Arts and Sciences, 1957
 * Harvey Prize, the Technion of Haifa, Israel, 1972
 * Alfred Noble Prize, 1939 (award of civil engineering societies in the US)
 * National Medal of Science, 1966, presented by President Lyndon B. Johnson
 * Kyoto Prize, 1985
 * Morris Liebmann Memorial Prize of the Institute of Radio Engineers, 1949
 * United States National Academy of Sciences, 1956
 * Medal of Honor of the Institute of Electrical and Electronics Engineers, 1966
 * Golden Plate Award of the American Academy of Achievement, 1967
 * Royal Netherlands Academy of Arts and Sciences (KNAW), foreign member, 1975
 * Member of the American Philosophical Society, 1983
 * Basic Research Award, Eduard Rhein Foundation, Germany, 1991
 * Marconi Society Lifetime Achievement Award, 2000
 * Donnor Professor of Science, MIT, 1958–1979

Selected works

 * Claude E. Shannon: A Symbolic Analysis of Relay and Switching Circuits, master's thesis, MIT, 1937.
 * Claude E. Shannon: "A Mathematical Theory of Communication", Bell System Technical Journal, Vol. 27, pp. 379–423, 623–656, 1948 (abstract).
 * Claude E. Shannon and Warren Weaver: The Mathematical Theory of Communication. The University of Illinois Press, Urbana, Illinois, 1949. ISBN 0-252-72548-4
 * Neil Sloane editor (1993) Claude Shannon: Collected Works, IEEE Press

title: Claude Shannon


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Cracking

Cracking may refer to:

 * Cracking, the formation of a fracture or partial fracture in a solid material studied as fracture mechanics
 * Performing a sternotomy
 * Fluid catalytic cracking, a catalytic process widely used in oil refineries for cracking large hydrocarbon molecules into smaller molecules
 * Cracking (chemistry), the decomposition of complex organic molecules into smaller ones
 * Cracking joints, the practice of manipulating one's bone joints to make a sharp sound
 * Cracking codes, see cryptanalysis
 * Whip cracking
 * Safe cracking
 * Crackin', band featuring Lester Abrams
 * Packing and cracking, a method of creating voting districts to give a political party an advantage

In computing:
 * Another name for security hacking; the practice of defeating computer security.
 * Password cracking, the process of discovering the plaintext of an encrypted computer password.
 * Software cracking, the defeating of software copy protection.

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

title: Cracking


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Community

Stonehenge Summer Solstice eve 02.jpg gathers at Stonehenge, England, for the summer solstice

A community is a social unit (a group of living things) with a shared socially significant characteristic, such as place, set of norms, culture, religion, values, customs, or identity. Communities may share a sense of place situated in a given geographical area (e.g. a country, village, town, or neighborhood) or in virtual space through communication platforms. Durable good relations that extend beyond immediate genealogical ties also define a sense of community, important to their identity, practice, and roles in social institutions such as family, home, work, government, TV network, society, or humanity at large. Although communities are usually small relative to personal social ties, "community" may also refer to large group affiliations such as national communities, international communities, and virtual communities.

The English-language word "community" derives from the Old French comuneté (Modern French: communauté), which comes from the Latin communitas "community", "public spirit" (from Latin communis, "common").

Human communities may have intent, belief, resources, preferences, needs, and risks in common, affecting the identity of the participants and their degree of cohesiveness.

Archaeology
Archaeological studies of social communities use the term "community" in two ways, paralleling usage in other areas. The first is an informal definition of community as a place where people used to live. In this sense it is synonymous with the concept of an ancient settlement—whether a hamlet, village, town, or city. The second meaning resembles the usage of the term in other social sciences: a community is a group of people living near one another who interact socially. Social interaction on a small scale can be difficult to identify with archaeological data. Most reconstructions of social communities by archaeologists rely on the principle that social interaction in the past was conditioned by physical distance. Therefore, a small village settlement likely constituted a social community and spatial subdivisions of cities and other large settlements may have formed communities. Archaeologists typically use similarities in material culture—from house types to styles of pottery—to reconstruct communities in the past. This classification method relies on the assumption that people or households will share more similarities in the types and styles of their material goods with other members of a social community than they will with outsiders.

Sociology
Early sociological studies regarded communities as fringe groups at the behest of local power elites. Such early academic studies include Who Governs? by Robert Dahl as well as the papers by Floyd Hunter on Atlanta. At the turn of the 21st century the concept of community was rediscovered by academics, politicians, and activists. Politicians hoping for a democratic election started to realign with community interests.

Ecology
In ecology, a community is an assemblage of populations—potentially of different species—interacting with one another. Community ecology is the branch of ecology that studies interactions between and among species. It considers how such interactions, along with interactions between species and the abiotic environment, affect social structure and species richness, diversity and patterns of abundance. Species interact in three ways: competition, predation and mutualism:
 * Competition typically results in a double negative—that is both species lose in the interaction.
 * Predation involves a win/lose situation, with one species winning.
 * Mutualism sees both species co-operating in some way, with both winning.

The two main types of ecological communities are major communities, which are self-sustaining and self-regulating (such as a forest or a lake), and minor communities, which rely on other communities (like fungi decomposing a log) and are the building blocks of major communities. Moreover, we can establish other non-taxonomic subdivisions of biocenosis, such as guilds.

Semantics
The concept of "community" often has a positive semantic connotation, exploited rhetorically by populist politicians and by advertisers to promote feelings and associations of mutual well-being, happiness and togetherness —veering towards an almost-achievable utopian community.

In contrast, the epidemiological term "community transmission" can have negative implications, and instead of a "criminal community" one often speaks of a "criminal underworld" or of the "criminal fraternity".

Gemeinschaft and Gesellschaft
In Gemeinschaft und Gesellschaft (1887), German sociologist Ferdinand Tönnies described two types of human association: Gemeinschaft (usually translated as "community") and Gesellschaft ("society" or "association"). Tönnies proposed the Gemeinschaft–Gesellschaft dichotomy as a way to think about social ties. No group is exclusively one or the other. Gemeinschaft stress personal social interactions, and the roles, values, and beliefs based on such interactions. Gesellschaft stress indirect interactions, impersonal roles, formal values, and beliefs based on such interactions.

Sense of community
In a seminal 1986 study, McMillan and Chavis identify four elements of "sense of community":

 * 1) membership: feeling of belonging or of sharing a sense of personal relatedness,
 * 2) influence: mattering, making a difference to a group and of the group mattering to its members
 * 3) reinforcement: integration and fulfillment of needs,
 * 4) shared emotional connection.

A "sense of community index" (SCI) was developed by Chavis and colleagues, and revised and adapted by others. Although originally designed to assess sense of community in neighborhoods, the index has been adapted for use in schools, the workplace, and a variety of types of communities.

Studies conducted by the APPA indicate that young adults who feel a sense of belonging in a community, particularly small communities, develop fewer psychiatric and depressive disorders than those who do not have the feeling of love and belonging.

Socialization

The process of learning to adopt the behavior patterns of the community is called socialization. The most fertile time of socialization is usually the early stages of life, during which individuals develop the skills and knowledge and learn the roles necessary to function within their culture and social environment. For some psychologists, especially those in the psychodynamic tradition, the most important period of socialization is between the ages of one and ten. But socialization also includes adults moving into a significantly different environment where they must learn a new set of behaviors.

Socialization is influenced primarily by the family, through which children first learn community norms. Other important influences include schools, peer groups, people, mass media, the workplace, and government. The degree to which the norms of a particular society or community are adopted determines one's willingness to engage with others. The norms of tolerance, reciprocity, and trust are important "habits of the heart", as de Tocqueville put it, in an individual's involvement in community.

Community development
Community development is often linked with community work or community planning, and may involve stakeholders, foundations, governments, or contracted entities including non-government organisations (NGOs), universities or government agencies to progress the social well-being of local, regional and, sometimes, national communities. More grassroots efforts, called community building or community organizing, seek to empower individuals and groups of people by providing them with the skills they need to effect change in their own communities. These skills often assist in building political power through the formation of large social groups working for a common agenda. Community development practitioners must understand both how to work with individuals and how to affect communities' positions within the context of larger social institutions. Public administrators, in contrast, need to understand community development in the context of rural and urban development, housing and economic development, and community, organizational and business development.

Formal accredited programs conducted by universities, as part of degree granting institutions, are often used to build a knowledge base to drive curricula in public administration, sociology and community studies. The General Social Survey from the National Opinion Research Center at the University of Chicago and the Saguaro Seminar at the Harvard Kennedy School are examples of national community development in the United States. The Maxwell School of Citizenship and Public Affairs at Syracuse University in New York State offers core courses in community and economic development, and in areas ranging from non-profit development to US budgeting (federal to local, community funds). In the United Kingdom, the University of Oxford has led in providing extensive research in the field through its Community Development Journal, used worldwide by sociologists and community development practitioners.

At the intersection between community development and community building are a number of programs and organizations with community development tools. One example of this is the program of the Asset Based Community Development Institute of Northwestern University. The institute makes available downloadable tools to assess community assets and make connections between non-profit groups and other organizations that can help in community building. The Institute focuses on helping communities develop by "mobilizing neighborhood assets" – building from the inside out rather than the outside in. In the disability field, community building was prevalent in the 1980s and 1990s with roots in John McKnight's approaches.

Community building and organizing

In The Different Drum: Community-Making and Peace (1987) Scott Peck argues that the almost accidental sense of community that exists at times of crisis can be consciously built. Peck believes that conscious community building is a process of deliberate design based on the knowledge and application of certain rules. He states that this process goes through four stages:

 * 1) Pseudocommunity: When people first come together, they try to be "nice" and present what they feel are their most personable and friendly characteristics.
 * 2) Chaos: People move beyond the inauthenticity of pseudo-community and feel safe enough to present their "shadow" selves.
 * 3) Emptiness: Moves beyond the attempts to fix, heal and convert of the chaos stage, when all people become capable of acknowledging their own woundedness and brokenness, common to human beings.
 * 4) True community: Deep respect and true listening for the needs of the other people in this community.

In 1991, Peck remarked that building a sense of community is easy but maintaining this sense of community is difficult in the modern world. An interview with M. Scott Peck by Alan Atkisson. In Context #29, p. 26. The three basic types of community organizing are grassroots organizing, coalition building, and "institution-based community organizing", (also called "broad-based community organizing", an example of which is faith-based community organizing, or Congregation-based Community Organizing).

Community building can use a wide variety of practices, ranging from simple events (e.g., potlucks, small book clubs) to larger-scale efforts (e.g., mass festivals, construction projects that involve local participants rather than outside contractors).

Community building that is geared toward citizen action is usually termed "community organizing". In these cases, organized community groups seek accountability from elected officials and increased direct representation within decision-making bodies. Where good-faith negotiations fail, these constituency-led organizations seek to pressure the decision-makers through a variety of means, including picketing, boycotting, sit-ins, petitioning, and electoral politics.

Community organizing can focus on more than just resolving specific issues. Organizing often means building a widely accessible power structure, often with the end goal of distributing power equally throughout the community. Community organizers generally seek to build groups that are open and democratic in governance. Such groups facilitate and encourage consensus decision-making with a focus on the general health of the community rather than a specific interest group.

If communities are developed based on something they share in common, whether location or values, then one challenge for developing communities is how to incorporate individuality and differences. Rebekah Nathan suggests in her book, My Freshman Year, we are drawn to developing communities totally based on sameness, despite stated commitments to diversity, such as those found on university websites.

Types of community

A number of ways to categorize types of community have been proposed. One such breakdown is as follows:

 * 1) Location-based Communities: range from the local neighbourhood, suburb, village, town or city, region, nation or even the planet as a whole. These are also called communities of place.
 * 2) Identity-based Communities: range from the local clique, sub-culture, ethnic group, religious, multicultural or pluralistic civilisation, or the global community cultures of today. They may be included as communities of need or identity, such as disabled persons, or frail aged people.
 * 3) Organizationally-based Communities: range from communities organized informally around family or network-based guilds and associations to more formal incorporated associations, political decision-making structures, economic enterprises, or professional associations at a small, national or international scale.
 * 4) Intentional Communities: a mix of all three previous types, these are highly cohesive residential communities with a common social or spiritual purpose, ranging from monasteries and ashrams to modern ecovillages and housing cooperatives.

The usual categorizations of community relations have a number of problems: (1) they tend to give the impression that a particular community can be defined as just this kind or another; (2) they tend to conflate modern and customary community relations; (3) they tend to take sociological categories such as ethnicity or race as given, forgetting that different ethnically defined persons live in different kinds of communities—grounded, interest-based, diasporic, etc.

In response to these problems, Paul James and his colleagues have developed a taxonomy that maps community relations, and recognizes that actual communities can be characterized by different kinds of relations at the same time:

 * 1) Grounded community relations. This involves enduring attachment to particular places and particular people. It is the dominant form taken by customary and tribal communities. In these kinds of communities, the land is fundamental to identity.
 * 2) Life-style community relations. This involves giving primacy to communities coming together around particular chosen ways of life, such as morally charged or interest-based relations or just living or working in the same location. Hence the following sub-forms:
 * 3) community-life as morally bounded, a form taken by many traditional faith-based communities.
 * 4) community-life as interest-based, including sporting, leisure-based and business communities which come together for regular moments of engagement.
 * 5) community-life as proximately-related, where neighbourhood or commonality of association forms a community of convenience, or a community of place (see below).
 * 6) Projected community relations. This is where a community is self-consciously treated as an entity to be projected and re-created. It can be projected as through thin advertising slogan, for example gated community, or can take the form of ongoing associations of people who seek political integration, communities of practice based on professional projects, associative communities which seek to enhance and support individual creativity, autonomy and mutuality. A nation is one of the largest forms of projected or imagined community.

In these terms, communities can be nested and/or intersecting; one community can contain another—for example a location-based community may contain a number of ethnic communities. Both lists above can be used in a cross-cutting matrix in relation to each other.

Internet communities
In general, virtual communities value knowledge and information as currency or social resource. What differentiates virtual communities from their physical counterparts is the extent and impact of "weak ties", which are the relationships acquaintances or strangers form to acquire information through online networks. Relationships among members in a virtual community tend to focus on information exchange about specific topics. A survey conducted by Pew Internet and The American Life Project in 2001 found those involved in entertainment, professional, and sports virtual-groups focused their activities on obtaining information.

An epidemic of bullying and harassment has arisen from the exchange of information between strangers, especially among teenagers, in virtual communities. Despite attempts to implement anti-bullying policies, Sheri Bauman, professor of counselling at the University of Arizona, claims the "most effective strategies to prevent bullying" may cost companies revenue.

Virtual Internet-mediated communities can interact with offline real-life activity, potentially forming strong and tight-knit groups such as QAnon.

title: Community


text:
Community college

A community college is a type of undergraduate higher education institution, generally leading to an associate degree, certificate, or diploma. The term can have different meanings in different countries: many community colleges have an open enrollment policy for students who have graduated from high school, also known as senior secondary school or upper secondary school. The term usually refers to a higher educational institution that provides workforce education and college transfer academic programs. Some institutions maintain athletic teams and dormitories similar to their university counterparts.

Australia
In Australia, the term "community college" refers to small private businesses running short (e.g. six weeks) courses generally of a self-improvement or hobbyist nature. Equivalent to the American notion of community colleges are Technical and Further Education colleges or TAFEs; these are institutions regulated mostly at state and territory level. There are also an increasing number of private providers colloquially called "colleges".

TAFEs and other providers carry on the tradition of adult education, which was established in Australia around the mid-19th century, when evening classes were held to help adults enhance their numeracy and literacy skills. Most Australian universities can also be traced back to such forerunners, although obtaining a university charter has always changed their nature. In TAFEs and colleges today, courses are designed for personal development of an individual or for employment outcomes. Educational programs cover a variety of topics such as arts, languages, business and lifestyle. They usually are scheduled to run two, three or four days of the week, depending on the level of the course undertaken. A Certificate I may only run for 4 hours twice a week for a term of 9 weeks. A full-time Diploma course might have classes 4 days per week for a year (36 weeks). Some courses may be offered in the evenings or weekends to accommodate people working full-time. Funding for colleges may come from government grants and course fees. Many are not-for-profit organisations. Such TAFES are located in metropolitan, regional and rural locations of Australia.

Education offered by TAFEs and colleges has changed over the years. By the 1980s, many colleges had recognised a community need for computer training. Since then thousands of people have increased skills through IT courses. The majority of colleges by the late 20th century had also become Registered Training Organisations. They offer individuals a nurturing, non-traditional education venue to gain skills that better prepare them for the workplace and potential job openings. TAFEs and colleges have not traditionally offered bachelor's degrees, instead providing pathway arrangements with universities to continue towards degrees. The American innovation of the associate degree is being developed at some institutions. Certificate courses I to IV, diplomas and advanced diplomas are typically offered, the latter deemed equivalent to an undergraduate qualification, albeit typically in more vocational areas. Recently, some TAFE institutes (and private providers) have also become higher education providers in their own right and are now starting to offer bachelor's degree programs.

Canada
In Canada, colleges are adult educational institutions that provide higher education and tertiary education, and grant certificates and diplomas. Alternatively, Canadian colleges are often called "institutes" or "polytechnic institutes". As well, in Ontario, the 24 colleges of applied arts and technology have been mandated to offer their own stand-alone degrees as well as to offer joint degrees with universities through "articulation agreements" that often result in students emerging with both a diploma and a degree. Thus, for example, the University of Guelph "twins" with Humber College and York University does the same with Seneca College. More recently, however, colleges have been offering a variety of their own degrees, often in business, technology, science, and other technical fields. Each province has its own educational system, as prescribed by the Canadian federalism model of governance. In the mid-1960s and early 1970s, most Canadian colleges began to provide practical education and training for the emerging and booming generation, and for immigrants from around the world who were entering Canada in increasing numbers at that time. A formative trend was the merging of the then separate vocational training and adult education (night school) institutions.

Canadian colleges are either publicly funded or private post-secondary institutions (run for profit).

In terms of academic pathways, Canadian colleges and universities collaborate with each other with the purpose of providing college students the opportunity to academically upgrade their education. Students can transfer their diplomas and earn transfer credits through their completed college credits towards undergraduate university degrees.

The term associate degree is used in Western Canada to refer to a two-year college arts or science degree, similar to how the term is used in the United States. In other parts of Canada, the term advanced degree is used to indicate a three- or four-year college program.

In Quebec, three years is the norm for a university degree because a year of credit is earned in the CÉGEP (college) system. Even when speaking in English, people often refer to all colleges as Cégeps; however, the term is an acronym more correctly applied specifically to the French-language public system: Collège d'enseignement général et professionnel (CEGEP); in English: College of General and Vocational Education. The word "college" can also refer to a private high school in Quebec.

 * Canadian community college systems
 * List of colleges in Canada
 * Colleges and Institutes Canada (CICan) – publicly funded educational institutions; formerly the Association of Canadian Community Colleges (ACCC)
 * National Association of Career Colleges – privately funded educational institutions; formerly the Association of Canadian Career Colleges

India
In India, 98 community colleges are recognized by the University Grants Commission. The courses offered by these colleges are diplomas, advance diplomas and certificate courses. The duration of these courses usually ranges from six months to two years.

Malaysia
Community colleges in Malaysia are a network of educational institutions whereby vocational and technical skills training could be provided at all levels for school leavers before they entered the workforce. The community colleges also provide an infrastructure for rural communities to gain skills training through short courses as well as providing access to a post-secondary education.

At the moment, most community colleges award qualifications up to Level 3 in the Malaysian Qualifications Framework (Certificate 3) in both the Skills sector (Sijil Kemahiran Malaysia or the Malaysian Skills Certificate) as well as the Vocational and Training sector but the number of community colleges that are starting to award Level 4 qualifications (Diploma) are increasing. This is two levels below a bachelor's degree (Level 6 in the MQF) and students within the system who intend to further their studies to that level will usually seek entry into Advanced Diploma programs in public universities, polytechnics or accredited private providers.

Philippines
In the Philippines, a community school functions as elementary or secondary school at daytime and towards the end of the day convert into a community college. This type of institution offers night classes under the supervision of the same principal, and the same faculty members who are given part-time college teaching load.

The concept of community college dates back to the time of the former Minister of Education, Culture and Sports (MECS) that had under its wings the Bureaus of Elementary Education, Secondary Education, Higher Education and Vocational-Technical Education. MECS Secretary, Cecilio Putong, who in 1971 wrote that a community school is a school established in the community, by the community, and for the community itself. Pedro T. Orata of Pangasinan shared the same idea, hence the establishment of a community college, now called the City College of Urdaneta.

A community college like the one in Abuyog, Leyte can operate with only a PHP 124,000 annual budget in a two-story structure housing more than 700 students.

United Kingdom
Except for Scotland, this term is rarely used in the United Kingdom. When it is, a community college is a school which not only provides education for the school-age population (11–18) of the locality, but also additional services and education to adults and other members of the community. This education includes but is not limited to sports, adult literacy and lifestyle education. Usually when students finish their secondary school studies at age 16, they move on to a sixth form college where they study for their A-levels (although some secondary schools have integrated sixth forms). After the two-year A-level period, they may proceed to a college of further education or a university. The former is also known as a technical college.

United States
In the United States, community colleges, sometimes called junior colleges, technical colleges, two-year colleges, or city colleges, are primarily public institutions providing tertiary education, also known as continuing education, that focuses on certificates, diplomas, and associate degrees. After graduating from a community college, some students transfer to a liberal arts college or university for two to three years to complete a bachelor's degree.

Before the 1970s, community colleges in the United States were more commonly referred to as junior colleges. That term is still used at some institutions. Public community colleges primarily attract and accept students from the local community and are usually supported by local tax revenue. They usually work with local and regional businesses to ensure students are being prepared for the local workforce.

Research
Some research organizations and publications focus upon the activities of community college, junior college, and technical college institutions. Many of these institutions and organizations present the most current research and practical outcomes at annual community college conferences.
 * The American Association of Community Colleges has provided oversight on community college research since the 1920s. AACC publishes a research journal called the Community College Journal.
 * The Community College Research Center (CCRC) at Teachers College, Columbia University, has been conducting research on community colleges since 1996 to identify barriers to students' post-secondary access and promising solutions. CCRC's publishes research reports, briefs, and resources geared toward a variety of community college stakeholders, including college and college system leaders, faculty and support staff, policymakers, and institutional researchers.
 * The Association of Community College Trustees (ACCT) has provided education for community college boards of directors and advocacy for community colleges since 1972. ACCT President and CEO J. Noah Brown published a book about the past, present, and future of community colleges, Charting a New Course for Community Colleges: Aligning Policies with Practice.
 * The Center for Community College Student Engagement at the University of Texas at Austin administers surveys and provides data analysis support to member colleges regarding various factors of student engagement and involvement in community colleges in the United States and Canada.
 * The Office of Community College Research and Leadership at the University of Illinois at Urbana–Champaign studies policies, programs, and practices designed to enhance outcomes for diverse youth and adults who seek to transition to and through college to employment. OCCRL's research spans the P-20 education continuum, with an intense focus on how community colleges impact education and employment outcomes for diverse learners. Results of OCCRL's studies of pathways and programs of study, extending from high school to community colleges and universities and to employment, are disseminated nationally and internationally. Reports and materials are derived from new knowledge captured and disseminated through OCCRL's website, scholarly publications, and other vehicles.

Several peer-reviewed journals extensively publish research on community colleges, including Community College Review and others.

title: Community college


text:
Civil Rights Memorial

The Civil Rights Memorial is an American memorial in Montgomery, Alabama, created by Maya Lin. The names of 41 people are inscribed on the granite fountain as martyrs who were killed in the civil rights movement. The memorial is sponsored by the Southern Poverty Law Center.

Design
The names included in the memorial belong to those who were killed between 1955 and 1968. The dates chosen represent a time when legalized segregation was prominent. In 1954 the U.S. Supreme Court ruled in Brown v. Board of Education that racial segregation in schools was unlawful and 1968 is the year of the assassination of Martin Luther King Jr. The monument was created by Maya Lin, who also created the Vietnam Veterans Memorial in Washington, D.C. The Civil Rights Memorial was dedicated in 1989.

The concept of Lin's design is based on the soothing and healing effect of water. It was inspired by a passage from King's 1963 "I Have a Dream" speech "...we will not be satisfied "until justice rolls down like waters and righteousness like a mighty stream..." The quotation in the passage, which is inscribed on the memorial, is a direct paraphrase of Amos 5:24, as translated in the American Standard Version of the Bible.  The memorial is a fountain in the form of an asymmetric inverted stone cone.  A film of water flows over the base of the cone, which contains the 41 names included. It is possible to touch the smooth film of water and to alter it temporarily, which quickly returns to smoothness. The memorial is designed in a timeline manner. It begins with Brown v. Board in 1954, and ends with Martin Luther King Jr.'s assassination in 1968.

Tours and location
The memorial is in downtown Montgomery, at 400 Washington Avenue, in an open plaza in front of the Civil Rights Memorial Center, which was the offices of the Southern Poverty Law Center until it moved across the street into a new building in 2001. The memorial may be visited freely 24 hours a day, 7 days a week.

The Civil Rights Memorial Center offers guided group tours, lasting approximately one hour. Tours are available by appointment, Monday to Saturday.

The memorial is only a few blocks from other historic sites, including the Dexter Avenue King Memorial Baptist Church, the Alabama State Capitol, the Alabama Department of Archives and History, the corners where Claudette Colvin and Rosa Parks boarded buses in 1955 on which they would later refuse to give up their seats, and the Rosa Parks Library and Museum.

"Civil Rights Martyrs"
The 41 names included in the Civil Rights Memorial are those of:

 * Louis Allen
 * Willie Brewster
 * Benjamin Brown
 * Johnnie Mae Chappell
 * James Chaney
 * Addie Mae Collins
 * Vernon Dahmer
 * Jonathan Daniels
 * Henry Hezekiah Dee
 * Roman Ducksworth Jr.
 * Willie Edwards
 * Medgar Evers
 * Andrew Goodman
 * Paul Guihard
 * Samuel Hammond Jr.
 * Jimmie Lee Jackson
 * Wharlest Jackson
 * Martin Luther King Jr.
 * Bruce W. Klunder
 * George W. Lee
 * Herbert Lee
 * Viola Liuzzo
 * Denise McNair
 * Delano Herman Middleton
 * Charles Eddie Moore
 * Oneal Moore
 * William Lewis Moore
 * Mack Charles Parker
 * Lemuel Penn
 * James Reeb
 * John Earl Reese
 * Carole Robertson
 * Michael Schwerner
 * Henry Ezekial Smith
 * Lamar Smith
 * Emmett Till
 * Clarence Triggs
 * Virgil Lamar Ware
 * Cynthia Wesley
 * Ben Chester White
 * Sammy Younge Jr.

"The Forgotten"
"The Forgotten" are 74 people who are identified in a display at the Civil Rights Memorial Center. These names were not inscribed on the Memorial because there was insufficient information about their deaths at the time the Memorial was created. However, it is thought that these people were killed as a result of racially motivated violence between 1952 and 1968.

 * Andrew Lee Anderson
 * Frank Andrews
 * Isadore Banks
 * Larry Bolden
 * James Brazier
 * Thomas Brewer
 * Hilliard Brooks
 * Charles Brown
 * Jessie Brown
 * Carrie Brumfield
 * Eli Brumfield
 * Silas (Ernest) Caston
 * Clarence Cloninger
 * Willie Countryman
 * Vincent Dahmon
 * Woodrow Wilson Daniels
 * Joseph Hill Dumas
 * Pheld Evans
 * J. E. Evanston
 * Mattie Greene
 * Jasper Greenwood
 * Jimmie Lee Griffith
 * A. C. Hall
 * Rogers Hamilton
 * Collie Hampton
 * Alphonso Harris
 * Izell Henry
 * Arthur James Hill
 * Ernest Hunter
 * Luther Jackson
 * Ernest Jells
 * Joe Franklin Jeter
 * Marshall Johnson
 * John Lee
 * Willie Henry Lee
 * Richard Lillard
 * George Love
 * Robert McNair
 * Maybelle Mahone
 * Sylvester Maxwell
 * Clinton Melton
 * James Andrew Miller
 * Booker T. Mixon
 * Nehemiah Montgomery
 * Frank Morris
 * James Earl Motley
 * Sam O'Quinn
 * Hubert Orsby
 * Larry Payne
 * C. H. Pickett
 * Albert Pitts
 * David Pitts
 * Ernest McPharland
 * Jimmy Powell
 * William Roy Prather
 * Johnny Queen
 * Donald Rasberry
 * Fred Robinson
 * Johnny Robinson
 * Willie Joe Sanford
 * Marshall Scott Jr.
 * Jessie James Shelby
 * W. G. Singleton
 * Ed Smith
 * Eddie James Stewart
 * Isaiah Taylor
 * Freddie Lee Thomas
 * Saleam Triggs
 * Hubert Varner
 * Clifton Walker
 * James Waymers
 * John Wesley Wilder
 * Rodell Williamson
 * Archie Wooden

title: Civil Rights Memorial