Julian Seifert
email: julian.seifert@uni-ulm.de

Markus Packeiser
email: markus.packeiser@uni-due.de

Enrico Rukzio
email: enrico.rukzio@uni-ulm.de

Adding Vibrotactile Feedback to Large Interactive Surfaces

Keywords: Interactive surfaces, vibrotactile feedback, touch-based interaction, multi touch

Interactive surfaces and multi-touch tables are increasingly available outside academic contexts, and are entering, for instance, work or educational contexts. A large variety of applications exists for a multitude of tasks. For interacting with these applications, existing interaction concepts are often directly mapped to the multi-touch surface, which is often limited by physical constraints. For instance, to enter text on an interactive surface, most often a virtual keyboard is used. However, users cannot feel when, for instance, they have accidentally pressed two keys at the same time. Research on mobile devices has identified vibrotactile feedback as an effective means to support users when interacting with touch screens. In this work, we present results of an experiment in which we investigated whether typical tasks (e.g., typing text, drag-and-drop of items) on interactive multi-touch surfaces can be supported by providing vibrotactile feedback directly on the surface * . We compared direct feedback with distal feedback provided on the user's body, as well as their combination. Surprisingly, our results show that all compared variants of vibrotactile feedback had no significant positive effect on the task performance. Yet participants rated tactile feedback significantly higher regarding interaction support and subjective speed compared to no provided feedback.

Introduction

Recently, large interactive surfaces have begun to come out of the labs and are entering diverse usage contexts such as domestic, or workplace environments. Reasons are maturing technologies and progress in interaction research, which enable an increasing number of use cases wherein direct multi-touch on interactive surfaces is the main interaction style. Touch-based interaction is commonly considered to be natural [START_REF] Dietz | Diamondtouch: a multi-user touch technology[END_REF] as users can interact with virtual objects as they expect it based on their experiences with real physical objects [START_REF] Ishii | Tangible bits: towards seamless interfaces between people, bits and atoms[END_REF]. However, depending on the task, the absence of correspond-ing tactile feedback of virtual objects decreases user experience and performance (which is in particular a challenge in the field of virtual reality [START_REF] Benali-Khoudja | Tactile interfaces: a state-ofthe-art survey[END_REF]). This challenge of missing corresponding tactile feedback applies also to touchbased interaction with hand-held mobile devices such as smartphones. One solution that has been identified to significantly increase the typing performance on virtual keyboards is vibrotactile feedback [START_REF] Brewster | Tactile feedback for mobile interactions[END_REF]. That is, users benefit from short vibrotactile sensations when touching a button, indicating that an effect has resulted from the input.

Evidently, vibrotactile feedback is a promising candidate for increasing performance and accuracy of touch-based interactions on large interactive multi-touch surfaces. However, it is not obvious how differences to hand-held devices (e.g., multitouch interactions, screen size, task-type) influence the positive effect of vibrotactile feedback.

In this work, we contribute findings of a user study investigating the effect of vibrotactile feedback during interaction with interactive surfaces enabling multi-touch. The study compared direct vibrotactile feedback on the surface with distal feedback on the user's wrist [START_REF] Mcadam | Distal tactile feedback for text entry on tabletop computers[END_REF], as well as the combination of both. As a base-line, no vibrotactile feedback was given. Surprisingly, our findings indicate that vibrotactile feedback provided directly on a surface does not increase the users' performance in a typing task as observed on hand-held devices. In fact, none of the tested feedback conditions results in a significant improvement compared to conditions wherein no feedback was provided. However, participants expressed that vibrotactile feedback (in any form) is helpful and preferred over no feedback.

In the remainder of this paper, we discuss related works, introduce our experimental setup, and discuss the results and observations gained during the experiment.

Related Work

Early work on vibrotactile feedback was done in the field of virtual reality (VR). In this context, the absence of tactile feedback while interacting with virtual objects was identified as a challenge and different approaches for providing force feedback (e.g., [START_REF] Brooks | Project GROPEHaptic displays for scientific visualization[END_REF]) and tactile feedback [START_REF]Overview[END_REF] have been introduced. For interaction with interactive surfaces such as touch screens, the challenge is similar: users can touch objects displayed on the screen. However, it is always the same sensory experience.

Similar as in VR, additional input devices can be used which provide vibrotactile feedback when necessary. For instance, the HapticPen enables one or multiple users to interact with a touch screen and experience individual feed-back [START_REF] Lee | Haptic pen: a tactile feedback stylus for touch screens[END_REF]. Marquardt et al. introduced the Haptic Tabletop Puck, a mouse-like device providing feedback which the user moves on the tabletop to experience different surface qualities [START_REF] Marquardt | The haptic tabletop puck: tactile feedback for interactive tabletops[END_REF]. McAdam and Brewster investigated the effect of distal feedback on typing tasks using a small touch screen [START_REF] Mcadam | Distal tactile feedback for text entry on tabletop computers[END_REF]. Conceptually, distal feedback is provided by the users' personal mobile phone and its built-in vibration alarm. In their study, they used external vibration actuators placed on the user's body. Their study results indicate that distal feedback improves users' typing performance compared to when no feedback was provided.

Among the approaches that include an external device which provides the vibrotactile feedback, all have in common that the interaction with objects is less or not at all natural because direct touching is not possible. Hence, approaches that provide tactile feedback directly on the surface are capable of maintaining the natural interaction. Brewster et al. investigated the effect of vibrotactile feedback provided directly on the touch screen of mobile phones [START_REF] Brewster | Tactile feedback for mobile interactions[END_REF]. They found that such feedback has a significant positive effect on users' performance.

Another approach for enriching the tactile experience on interactive surfaces was presented by Bau et al. with TeslaTouch [START_REF] Bau | Teslatouch: electrovibration for touch surfaces[END_REF]. TeslaTouch is based on electro-vibration and hence, no physical movement of the surface is required to create the feedback. However, the electrovibration changes the force of attraction between the touching finger and the surface, which results in a specific perceived friction when moving the finger. Therefore, the feedback can only be provided for dragging interactions.

In this work, we examine the approach of providing tactile feedback through attaching vibration actuators at the bottom side of a large interactive surface which allows us to consider not only the dragging of objects but also tasks such as typing, in which the fingers of the user only touch the surface to trigger a button without dragging. Further, the size of the interactive surface is of relevance when considering multi-touch interactions.

User Study

We designed and conducted an experiment1 in order to investigate how vibrotactile feedback effects interaction with an interactive surface in comparison to settings with distal feedback and without any feedback. In the following, we introduce the design, tasks, and apparatus of the user study.

Design. We applied a within-subject design. The independent variable was the feedback: direct feedback on the interactive surface, distal feedback provided on the user's body, and combined direct and distal feedback. Finally, as baseline, no feedback was provided.

In counterbalanced order, participants used each of the four feedback variants to complete a series of tasks, which were also presented in counterbalanced order. While interacting with the interactive surface, participants were standing and allowed to move around the table. After each round with a feedback variant, participants filled in a questionnaire rating the previously tested feedback variant.

Tasks. Similar to previous work, we argue that typing is not the primary and only activity that is likely to be performed with an interactive surface. Hence, we included two additional tasks to test the effect of each feedback variant. These required dragand-drop actions, the use of multiple fingers at the same time, and a steering task. 1. Typing task. In the typing task, participants were asked to type six English sentences during each feedback condition. The sentences were taken from a standard set designed for typing performance testing [START_REF] Mackenzie | Phrase sets for evaluating text entry techniques[END_REF]. The sentences are of equal length and complexity and do not contain special characters or punctuation marks.

The user interface of the typing task application shows three items: the given sentence to type, a text field, and a virtual QWERTY keyboard (see Fig. 1a). Users can move the virtual keyboard to a preferred position in which they find it comfortable to type. Vibrotactile feedback (if available) was provided when hitting a character key on the virtual keyboard.

The collected data consisted of the task completion time, the number of corrections, and the number of errors.

2. Puzzle. In the puzzle task, participants were given a number of shapes on the interactive surface which had to be matched with predefined positions which were indicated by gray placeholders (see Fig. 1b). Vibrotactile feedback (if available) was provided when the user managed to place an item on its target (considering location and rotation within a specific tolerance). The puzzle was solved when all items were positioned correctly. The collected data were the task completion time and the number of times an item was released outside the accepted tolerance.

3. Steering task. In the steering task, participants were asked to steer a rectangle through a given path without touching the borders of the path (see Fig. 1c). When they reached the end of the path, participants had to follow the path back to the starting point. Vibrotactile feedback (if available) was provided when the distance between the path border and any corner point of the rectangle was less than a specific threshold.

The collected data encompassed the task completion time and the number of times the rectangle shape accidentally hit the border of the path.

Apparatus. The apparatus system for the experiment consists of an interactive surface which is augmented with four vibration actuators (see Fig. 2a). The interactive surface is based on frustrated total internal reflection (FTIR) for sensing multiple touch events simultaneously. The surface display is based on a rear projection (1280×1024 px), controlled by a computer which runs surface applications.

To generate the vibrotactile feedback that can be perceived when touching the surface of the multi-touch table, four 50 Watt low-frequency speakers (20-80 Hz) are mounted inside the interactive surface. They are powered by two 100 Watt amplifiers that are connected to the surface computer. In order to provide vibrotactile feedback, the running surface application plays an audio file which specifies the vibration pattern (a square wave was empirically found to produce a strong tactile sensation on the surface). Similar to the direct feedback, the distal feedback is generated using a vibration actuator which was attached to the participant's wrist (see Fig. 2c). Participants. Through an email list, we recruited 18 participants (10 males and 8 females) aged between 21 and 31 years. Participants were randomly selected. All but one participant (a teacher) were students with diverse backgrounds (technical and humanities). Participants received 10 Euro after the study as a reward.

Hypotheses. Overall, we hypothesized that vibrotactile feedback has a positive effect on the interaction. In particular: H0: Direct vibrotactile feedback provided by the surface leads to better (faster task completion and less errors) performance during interaction (typing, puzzle, and steering) compared to no feedback and to distal feedback. H1: Combined distal and direct feedback outperforms their separate effect (faster interaction and less errors). H2: Direct feedback is subjectively preferred over distal and combined feedback by users.

Results

We hypothesized that vibrotactile feedback has a positive effect on the task completion time (H0). To our surprise, the mean task completion times for the three tasks are very close to each other. As figure 3 shows, in the typing task, the average completion time for the condition 'no feedback' is higher (M=72.7s) com-pared to distal (M=68.4s), direct (M=66.6s), and combined feedback (M=64.8s). Yet testing with a one-way repeated-measures ANOVA shows that differences are not significantly different (F(3; 51)=1.76; p=.17). Moreover, for the puzzle and the steering task, the direct feedback resulted in the longest completion times. This raises the question why direct vibrotactile feedback has a significant positive effect on typing performance when using a mobile device (see [START_REF] Brewster | Tactile feedback for mobile interactions[END_REF]), however, not when applied on a large surface. Further, we compared the number of fixes (how many times the backspace key was pressed). Overall, there is a significant effect (F(1.77; 29.99)=6.77; p=.005): Direct feedback (M=4.22, SD=4.70), distal feedback (M=4.28, SD=3.14), and combined feedback (M=4.72, SD=4.01) equally often required the user to correct typing errors, followed by no feedback (M=10.05, SD=8.92). A pairwise comparison shows that only direct feedback requires significantly less fixes com-pared to no feedback (p=.04).

The minimum string distance (i.e., Levenshtein distance) which gives an estimation of the number of errors made, did not show significant differences between the four feedback types (F(3; 51)=.38; p>.05).

During the task of solving the puzzle, participants performed numerous drag-anddrop actions. This type of interaction differs from typing as the user's fingers are in contact with the surface for longer times. Hence, vibrotactile feedback should help to place the puzzle pieces in place correctly. However, looking at the average number of falsely placed pieces, it shows that combined feedback resulted in the highest number of errors (M=5.9; SD=3.3), followed by distal (M=4.8; SD=3.7), no feedback (M=4.3; SD=1.7), and direct feedback (M=4.1; SD=1.7), yet the differences are not significant (F(3; 51)=.81; p>.05).

Comparing the amount of errors made during the steering task shows no significant differences (F(3, 51)=2.46; p>.05). However, the numbers show a tendency indicating that feedback is helping: no feedback (M=4.89, SD=4.32) compared to direct (M=2.72, SD=2.73), distal (M=2.61, SD=2.35), and combined feedback (M=2.83, SD=3.22).

These results contradict to our hypothesis H0, which consequently has to be rejected. Further, the combination of direct and distal feedback does not result in better results. Consequently, H1 has to be rejected as well.

0"

10" 20" 30" 40" 50" 60" 70" 80" 90"

Typing"

Puzzle"

Steering"

Task%Comple,on%Time%(Seconds)%

Tasks%

No"Feeback" Direct" Distal"

Combined"

After each task, participants rated the feedback type via different statements (see Fig. 4) on a 5-point scale (1=fully disagree). Regarding the statement S1 ('The feedback irritated me.'), participants did not rate the feedback types significantly different (χ 2 (18)=5.8; p>.05). For all other statements, significant differences were reported, as illustrated in Fig. 4. However, interestingly the only significant differences are those between conditions in which feedback was given and the baseline condition in which no feedback was provided, as shown by pairwise comparison. For instance, in statement S3 ('The feedback allowed me to quickly finish the task.'), all three conditions in which vibrotactile feedback was provided were rated the same on average (Mdn=4.0). In statements S4 and S5, distal feedback was rated lower compared to direct and combined feedback. As these differences are not significant, it might at least indicate that the presence of direct feedback is appreciated by users. These subjective ratings indicate that from the users' point of view, it only matters that feedback is provided at all -not how this is implemented. Accordingly, hypothesis H2 cannot be confirmed.

Discussion & Conclusion

In this work, we investigated the effect of vibrotactile feedback on interaction with large interactive surfaces. Feedback provided directly on the surface, distal, or combined, did not have an effect on the users' performance. In fact, this result is surprising as previous work showed that vibrotactile feedback significantly improves speed and accuracy. One obvious explanation for the small objectively measured effect is that performing touch and drag-and-drop interactions on an interactive surface already causes strong tactile sensations. Hence, a vibrotactile feedback has to be even stronger compared to this resulting sensation at the users' fingertips. In the case of mobile handheld devices, we hypothesize that the hand holding the device is mainly responsible for feeling the vibrotactile feedback, rather than the finger used for input.

In addition, the results of this experiment depend strongly on the used FTIR technology, which requires users to perform stronger touches compared to a capacitive touch screen. Hence, future work should investigate if and how vibrotactile feedback is beneficial on capacitive surfaces such as the Samsung SUR40. The data measured during the experiment, such as task completion time different error values, did not support our initial hypothesis that direct feedback has a positive effect on the performance. However, users reported that any given type of vibrotactile feedback is valuable to them as they felt that they performed tasks faster.

As the tested feedback types (direct, distal, and combined) do not cause considerable differences in terms of speed (task completion) and accuracy (errors), the decision regarding which type of feedback to offer depends mainly on the given application design. For instance, in multi-user games it might be interesting to provide a common feedback for all players directly on the surface. At the same time, private feedback could be provided via distal means.

Fig. 1 .

 1 Fig. 1. Graphical user interfaces of the task applications: (a) a typing task, (b) a puzzle, and (c) a steering task.

Fig. 2 .

 2 Fig. 2. The apparatus systems: (a) An interactive surface using rear projection. (b) Four 'bass pumps' mounted inside the interactive surface in order to generate low-frequency vibrations. (c) C2 vibration actuator to provide distal feedback.

Fig. 3 .

 3 Fig. 3. Task completion times for the tasks 'typing', 'puzzle', and 'steering' (Error bars show the standard deviation).

Fig. 4 .

 4 Fig. 4. Subjective ratings of the four feedback conditions (Bars show medians; error bars show standard deviation).

Acknowledgement

This work has been conducted in the Emmy Noether research group Mobile Interaction with Pervasive User Interfaces funded by the German Research Foundation.


Felix Kistler

Elisabeth André

Samuel Mascarenhas

André Silva

Ana Paiva
email: ana.paiva@gaips.inesc-id.ptnick.degens

Nick Degens

Gert Jan Hofstede
email: gertjan.hofstede@wur.nle.krumhuber

Eva Krumhuber

Arvid Kappas
email: a.kappas@jacobs-university.der.s.aylett@hw.ac.uk

Ruth Aylett

Traveller: An Interactive Cultural Training System Controlled by User-Defined Body Gestures

Keywords: User Defined Gestures, Kinect, Full Body Tracking, Depth Sensor, Interaction, Interactive Storytelling, Cultural Training

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Experience-based role play with virtual agents offers great promise for social training.

In this paper, we present a system called Traveller (Train for Virtually Every Locality) that makes use of such an approach to educate young adults (18-25) in cultural sensitivity. The system implements a virtual storytelling environment in which the users learn by finding out how to appropriately interact with characters simulating different cultures as defined by Hofstede [START_REF] Hofstede | Synthetic cultures: Intercultural learning through simulation games[END_REF].

It is vital to the success of experience-based learning with virtual characters that the user is able to interact with them in a socially believable manner. As depth cameras have become broadly available with the Microsoft Kinect1 , we decided to make use of novel full body interaction techniques that allow trainees to practice culturallyvarying non-verbal behaviors directly. However, the identification of intuitive gestures that are expressive enough to enable meaningful interaction with virtual characters is a challenge for the interaction designer. Given that gesture sets are usually chosen by the developers themselves, they do not necessarily have to be intuitive for the majority of users.

An approach that employs a user-defined gesture set has been presented by Wobbrock et al. for surface computing [START_REF] Wobbrock | User-defined gestures for surface computing[END_REF], and was adapted for other areas, such as public displays [START_REF] Kurdyukova | Studying user-defined iPad gestures for interaction in multi-display environment[END_REF] or human robot interaction [START_REF] Obaid | User-defined body gestures for navigational control of a humanoid robot[END_REF]. Its basic idea is to show specific effects within a system to users, who are then asked to perform gestures that should trigger these effects. The gesture performances are recorded and later analyzed to find gesture candidates that represent the choice of a majority of users. We adopted this approach for Traveller, in which full body gestures performed by the users trigger ingame actions that can vary in their type. For the present purpose we focus on two common action types: a) navigation, i.e. changing the position and perspective of the virtual camera and b) dialogue with virtual agents.

In the next section, we describe the scenario, including the story script and learning goals of our system, and the architecture used to model the agents' behavior. In Section 3, the development of the user-defined gestures set is depicted, which represents the main part of the interaction within our system. Afterwards, a secondary interaction type for cases in which the main interaction is hard to apply is presented, followed by a conclusion.

Scenario

Background Story and Learning Goals

In Traveller, users take the role of a character that has never been abroad. Throughout the game, they follow in the footsteps of their deceased grandfather, who used to travel the world. Their grandfather has left a letter, to be opened on the character's 18 th birthday, in which he states that he has hidden a treasure long ago. To keep it safe, he has left pages of his travel journal in a few countries that he used to visit. To find these pages, the users have to travel to three different countries, and interact with the inhabitants of those countries in so-called critical incidents. The journal pages tell the users where to go to next, and also describe their grandfather's experiences as a beginning traveller.

The story starts at their grandmother's café, where the grandmother gives initial instructions. Afterwards, the users travel to the first country, in which they have to get directions from a group of strangers in a bar (first critical incident), have to find the responsible supervisor in a nearby museum in order to receive entry permission for a park (second critical incident), and support or blame the supervisor when he knocks over a priceless artifact (third critical incident). In the second country, the users have to interact with an elderly man who wants to sit in the users' seat, interact with a train conductor who claims they have the wrong ticket, have a stranger join them for dinner and who might steal their wallet, and help out at a café to earn some money. In the third country, the users have to decide whether they care more about finding the treasure, or helping somebody in need, and interact with people at a party. At the end of the game, the users discover that the hidden treasure was actually in the experiences and adventures that they had during their travels.

The characters in each country have different rules for behavior and interpretation, depending on their synthetic culture. Therefore, if users do not select the appropriate actions, the virtual characters can get upset, and be unwilling to help them on their way. This can sometimes lead to obvious misunderstands, or even outright conflicts, but also to situations in which the users do not realize that they have offended the characters. The cultural configuration of the virtual characters is based on synthetic cultures [START_REF] Hofstede | Synthetic cultures: Intercultural learning through simulation games[END_REF]. These synthetic cultures reflect the extremes of Hofstede's dimensions of culture [START_REF] Hofstede | Cultures and organizations: Software of the mind: Intercultural cooperation and its importance for survival[END_REF], which were empirically validated across several nations. At the moment, we only use three dimensions to determine the behavior of the characters: power distance, individualism vs. collectivism, and masculinity vs. femininity.

The aim of Traveller is comprised of an affective goal, which focuses on the users' emotions, and a cognitive goal, which focuses on the users' knowledge and understanding. The affective goal focuses on making the users aware that their rules for interpretation of appropriate behavior might be incorrect. For example, in certain cultures, women are not willing to talk to a stranger. As a stranger, it is easy to think they are just rude, but it might just be that it is inappropriate for women to talk to a stranger in public. Self-reflection and articulation of how the other person's behavior makes one feel then allows the users to recognize their emotions as they arise in reaction to such a novel situation. These emotional responses may not always be positive in the first place, but should be accepted and integrated without feelings of prejudice. The cognitive goal focuses on making the user understand general differences in cultures. As there are similar actions that occur within each country, the users are able to see the effect of similar actions in different countries. For example, a stranger would be treated differently in a collectivistic culture, than in an individualistic culture. By experiencing similarities and differences between cultures, the users see how various standpoints of cultural groups lead to respective behavior and assumptions. The attempt to see the same action from the point of view of people from another culture in turn prompts perspective taking and provides the foundation for empathic responses.

Cultural Agent Architecture

The reasoning and behavior of the characters in Traveller is driven by the Social Importance Dynamics (SID) model [START_REF] Mascarenhas | Can i ask you a favour? -a relational model of socio-cultural behaviour[END_REF], which was integrated in the FAtiMA agent architecture [START_REF] Dias | Fatima modular: Towards an agent architecture with a generic appraisal framework[END_REF]. The SID model is an adjustable model of cultural influences in social behavior that is based on Kemper's status-power theory [START_REF] Kemper | Status, power and ritual interaction: a relational reading of Durkheim, Goffman, and Collins[END_REF]. The model augments the standard BDI agent framework [START_REF] Georgeff | Decision-making in an embedded reasoning system[END_REF] with a set of social dynamics that constitute human socio-cultural behavior. More specifically, it models the human notion that others, from a relational perspective, are more or less important and that importance determines how much we are willing to act in their best interests. Conversely, it also determines how much we feel entitled to have others act in our favor. To give an example, if a close friend or a family member needs a place to stay overnight, we would gladly provide a room for him or her to sleep. However, the same is less likely to happen if the person is a stranger. Still, if the stranger simply asked for directions to a hotel, then most of us would comply.

Cultures greatly differ on how much social importance (SI) is attributed to others and how much it is conveyed by certain actions. For instance, in many Western cultures, cheek kissing is a very common greeting between acquaintances of the opposite sex. Oppositely, in China it is considered to be a very intimate act. The SID model enables the representation of such conventions. To illustrate how the model has been applied in Traveller, we consider the second critical incident of the first country that takes place in a museum, and in which the user is trying to find a supervisor of a wild park to ask for entry permission. If the user chooses to approach the supervisor directly, the supervisor's response will depend on his cultural configuration. One dimension of this configuration is power distance, which indicates how people treat others with higher status. If the supervisor's culture has a high power distance, he will not accept a direct request from the user with lower status. If the power distance score is low instead, the supervisor will directly accept the request.

Besides the SID model, the architecture also features the capacity to synthesize emotions in response to events that happen in the virtual environment, following the OCC appraisal theory [START_REF] Ortony | The Cognitive Structure of Emotions[END_REF]. This is essential for making the characters seem believable and for the user to establish an empathic relation with them. The architecture has also two different layers to control the behavior of the agents, a Reactive layer and a Deliberative Layer. The first one is responsible for generating quick reactions to events, such as a facial expression triggered by an emotion. The second one endows agents with goal-oriented behavior. These capabilities were already existent in FAti-MA and more details about them are described in [START_REF] Dias | Feeling and reasoning: a computational model for emotional agents[END_REF].

The virtual environment for the scenario was implemented using the cross-platform game engine Unity3D2 . The ION framework [START_REF] Vala | ION framework -a simulation environment for worlds with virtual agents[END_REF] is used to manage the communication between the agent architecture and the 3D world. In addition, characters speak by using the Microsoft Speech API and voices from CereProc3 .

Development of User-defined Gestures

For the development of our user-defined gesture set, we conducted a study that is described in the following section. In the subsequent section, we present the resulting gesture set and how we integrated it into our application.

3.1

Gesture Study

We conducted our gesture study for the introduction scenario and the first two critical incidents within the first country. They included the following in-game actions to be triggered via body gestures: yes, no, sit at bar and wait, approach group, ask for directions, leave the bar, ask about supervisor, ask guard to talk to supervisor, approach supervisor, ask permission.

Whenever an interaction was requested by the system, we displayed all available actions as text boxes on the screen and the users' task was to invent and perform a gesture for each displayed option, one after the other. Those gesture performances were recorded on video and analyzed later to find gesture candidates for the investigated actions. The gesture candidates were chosen according to an agreement score based on how often users performed the same gesture for one action. In this way, we got one or two gesture candidates per action depending on the level of agreement between the participants. In the case of two gesture candidates we needed to decide which one we would use in the final gesture set. This was done in a way that the single gestures fitted to each other, and there was no problem of ambiguous gestures in parallel.

The final gesture set and its integration is described in the next chapter. Further details about the gesture study, the results of its analysis, and the implementation of the gesture recognition can be found in [START_REF] Kistler | User-defined body gestures for an interactive storytelling scenario[END_REF].

Table 1. Implemented gesture candidates and related actions (in brackets). head nod (yes)

head shake (no) sit down (sit at bar and wait)

step forward (approach group) turn away (leave the bar) point to front (ask guard to talk to supervisor) tip on shoulder (ask permission) arms out (ask for directions, ask about supervisor)

Gesture Set and its Integration

For integrating the gestures in our application we use the Kinect for Windows SDK 4together with our FUBI framework of which an earlier version has already been presented in [START_REF] Kistler | Natural interaction with culturally adaptive virtual characters[END_REF]. FUBI achieves gesture recognition by using an XML-based definition language. To instruct users, we display symbols (single images or animations) that visualize how the gestures for these actions should be performed. The gesture candi-dates we extracted in our study and integrated in the first part of our scenario are depicted by their onscreen symbols in Table 1. Most of them are actually animations, but only one or two important key frames are displayed for reasons of clarity. As soon as a symbol is displayed on screen, the recognition framework automatically checks the corresponding recognizer for the closest user in the depth sensor's field of view.

In case the recognition has been successful, it triggers an event related to the symbol in the same way as it is done for default interface buttons in Unity3D. Fig. 1 depicts a scene of the first critical incident displaying four symbols of the new gesture set.

GUI Interaction

During the further development of Traveller's story, it became clear that our scenario would include interactions that sometimes have multiple conversational actions in parallel that would be hard to represent with unambiguous gestures. Therefore, we decided to add a second type of interaction to our application. In case many conversational actions are necessary at a specific point in time, we group those actions into a dialogue menu as shown in Fig. 2. For entering the dialogue menu, users have to perform the "arms out" gesture as depicted in Table 1. When the dialogue menu is available, the symbol for the "arms out" gesture is shown in parallel to the other currently available actions, which are directly represented by gesture symbols. When the users perform the "arms out" gesture, the dialogue menu opens with the additional available conversational actions and one option to close the menu again. Within the menu, the options are arranged around a circle in the middle of the screen, with each of them occupying an equally sized sector around the middle circle. For selecting one of the options in the dialogue menu, users first have to stretch out their hand to the front, wait until the menu gets activated, and then perform a swiping gesture in the direction of the option they would like to select. Activation of the menu is visualized by the middle circle changing its color from blue to yellow. In addition, the circle always contains textual instructions for what to do next. As soon as the start of a swiping gesture is recognized, the corresponding arrow gets a little stretched in its pointing direction, and also changes its color to yellow together with the background of the corresponding action text. As soon as the swipe is completed and thus a selection is performed successfully, a sound is played for additional feedback.

In this way, we keep the freedom to develop the story with as many and complex actions as we want, without worrying about how all of them could be represented by unambiguous gestures. However, the interaction modality remains the same for all ingame actions, and the two interaction types are similar enough to provide a fluent user experience.

Fig. 2. GUI Interaction menu

Conclusion

In this paper, we presented a novel approach to culture training that is based on role play with virtual characters. By engaging in interactions with characters that simulate different synthetic cultures, users may actively experience the challenges of cultural communication. Particular emphasis was given to the design of natural forms of gesture-based interaction to achieve the required social immersion which we consider as a decisive factor of success for social learning. First informal studies with the system at public events have shown that users are very engaged with the system, eager to explore the scenarios and enjoyed the gesture-based interaction. Future user studies will investigate to what extent interaction with the system may foster cultural awareness.

Fig. 1 .

 1 Fig. 1. Gesture symbols in the first critical incident.

http://www.xbox.com/KINECT

http://unity3d.com

http://www.cereproc.com

http://www.kinectforwindows.org

Acknowledgments. This work was funded by the European Commission within FP7 under grant agreement eCute (FP7-ICT-257666).


Saila Ovaska
email: saila.ovaska@uta.fi

User Experience and Learning Experience in Online HCI Courses

Keywords: HCI Education, online education, MOOC, User Experience

Several Massive Open Online Courses (MOOCs) have become available also in the field of Human-Computer Interaction (HCI), in addition to other fields of study. How do they operate, and what do they teach? We compare two HCI MOOCs with a locally composed small scale online HCI course that was built and launched in 2012, and discuss issues in pedagogy, user experience and learner experience in online HCI education.

Introduction

A Massive Open Online Course (MOOC) is a Virtual Learning Environment (VLE) where anybody interested in the topic of the course can sign up and participate remotely. Distance education without personal face-to-face interaction between educators and students is not a novel idea-online education has existed in various forms for decades [START_REF]Online Learning in Computing[END_REF][START_REF] Petre | Innovations in Large-Scale Supported Distance Teaching: Transformation for the Internet, not just Translation[END_REF][START_REF] Petre | What's the Value Proposition of Distance Education?[END_REF], and Learning Management Systems (LMS) such as Blackboard and Moodle have become ubiquitous [START_REF] Martin | Will Massive Open Online Courses Change How We Teach?[END_REF]. According to Daniel [START_REF] Daniel | Making Sense of MOOCs: Musings in a Maze of Myth, Paradox and Possibility[END_REF], the first online "MOOC" was arranged in 2008, and, contrary to most current MOOC instances, it was based on philosophy of connectivism and networking, life-long learning and distributed content [START_REF] Cormier | What is a MOOC? Video available at[END_REF]. Daniel calls it "cMOOC": it differs quite a lot in pedagogy from more recent "xMOOC"s that usually evolve around a more standard course structure with lectures, assignments and other content available on the course site or in open streaming video platforms.

What makes MOOCs special is their open nature: they do not link directly to university degree studies but are open and free to all interested. There is quite a lot of variation in how they are organized, but many are arranged by a special platform and service provider (such as Coursera, edX, Khan Academy, and UdaCity, to mention some) that collaborates with educators who provide the content material. Because of the novelty of the idea, the policies vary a great deal from one course to the next, including questions about practical things such as availability of certificates and possible fees of accreditation, ownership and copyright of the content materials, and relationship with established course modules at universities. Still, MOOCs seem to bring new opportunities for learning to many, in particular to those who live in the develop-ing world [START_REF] Leber | In the Developing World, MOOCs Start to Get Real[END_REF] or cannot afford the high tuition fees of on-campus education [START_REF] Daniel | Making Sense of MOOCs: Musings in a Maze of Myth, Paradox and Possibility[END_REF]. All age groups can take part, even in rural areas with shortage of competent teachers [START_REF] Daniel | Making Sense of MOOCs: Musings in a Maze of Myth, Paradox and Possibility[END_REF].

A pertinent question posed by educators is whether MOOCs will eventually change the way we teach [START_REF] Martin | Will Massive Open Online Courses Change How We Teach?[END_REF][START_REF] Russell | Will Massive Online Open Courses (MOOCs) Change Education?[END_REF]. Furthermore, students are increasingly likely to request institutions to acknowledge their prior learning obtained through MOOCs.

Reports about early experiences with MOOCs in various areas are abounding, at least from the educator perspective [START_REF] Cooper | Reflections on Stanfords's MOOCs[END_REF][START_REF] Daniel | Making Sense of MOOCs: Musings in a Maze of Myth, Paradox and Possibility[END_REF][START_REF] Hardesty | Lessons Learned from MITx's Prototype Course[END_REF][START_REF] Hyman | In the Year of Disruptive Education[END_REF][START_REF] Leber | In the Developing World, MOOCs Start to Get Real[END_REF][START_REF] Martin | Will Massive Open Online Courses Change How We Teach?[END_REF]. The reported first experiences with MOOCs are varied. Drop-outs are common. Only a fraction of those who initially register finish all required parts of the course. On the other hand, much of the feedback is positive and encouraging, so that the courses will be improved on and run a second time. However, many experience reports point out the need for pedagogy and learning expertise in the design of MOOCs.

Background and Motivation for Our Work: HCI Education

In this paper we discuss three courses in the field of HCI. The Stanford HCI Course, arranged by Scott Klemmer [START_REF] Klemmer | Human-Computer Interaction[END_REF] in Coursera, launched its third instance in April, 2013. The first two times when it was given reached more than 100,000 registrations [START_REF] Russell | Will Massive Online Open Courses (MOOCs) Change Education?[END_REF]. Another HCI Course was opened to the public by Alan Dix [START_REF] Dix | HCI Course[END_REF] in early 2013. Both of these are open access MOOCs but with a bit different focus and methods.

We created an online HCI course (nicknamed "CUX", "Course on User Experience") in-house during 2012. CUX is not open to everybody and by no means "massive". It is designed for the students at our university who start their degree studies for MSc in Human-Technology Interaction. The MSc program is targeted to students who have a bachelor's degree in a suitable field, such as Computer Science. When starting in the program, some of the new students lack formal education in the basics of HCI, at least to the extent already covered in our own BSc program.

The main motivation for arranging an online HCI course for the students is to give them a compact understanding of the basics that are a prerequisite for the courses in the MSc program. The yearly intake in the MSc program is less than 20 students, and only a handful of them are required to start their studies on the introductory CUX course.

The MSc program started in 2001, and during the years we have tried out several pedagogical solutions for the introductory classes, ranging from participation in ordinary teacher-led class meetings to blended learning and self-study arranged with a Moodle LMS as a central repository of readings, but without any guidance and assignments the online studies solution proved inefficient. Structured assignments with deadlines and personalized guidance and feedback are needed for learning [START_REF] Petre | What's the Value Proposition of Distance Education?[END_REF].

Our focus in this paper is pragmatic. While CUX development coincided with the advent of the MOOCs in HCI, now that they exist, could parts of these courses be utilized locally to support and perhaps partially even substitute locally developed content? What differences are there in these three courses? We will next turn to look at the courses in more depth.

The HCI Courses as Learning Experiences

Many studies (such as [START_REF] Richards | Usability Attributes in Virtual Learning Environments[END_REF][START_REF] Sutcliffe | Comparing User Experience and Performance in SecondLife and Blackboard[END_REF]) focus on user experience in Virtual Learning Environments, but a closer inspection of these studies reveals that the VLEs in question are 3D virtual worlds such as SecondLife and not MOOC platforms. The importance of good learning experience in all web-based learning is recognized [START_REF] Abowd | Teaching and Learning as Multimedia Authoring: The Classroom 2000 Project[END_REF][START_REF] Kester | Designing Support to Facilitate Learning in Powerful Electronic Learning Environments[END_REF][START_REF] Notess | Usability, User Experience, and Learner Experience[END_REF]. All activity within the VLE is carried out through the interface, making usability and user experience integral parts of the learning experience, and affecting the learning outcomes [START_REF] Dyson | Evaluating Virtual Learning Environments: What Are We Measuring[END_REF]. The educational setting will need to encompass both pedagogy and technology [START_REF] Day | Evaluating a Web Lecture Intervention in a Human-Computer Interaction Course[END_REF]. Students need to be motivated to study the material, and the learning tasks and support for them need to be designed so that they enforce effective learning [START_REF] Kester | Designing Support to Facilitate Learning in Powerful Electronic Learning Environments[END_REF].

The two MOOCs and also CUX can be described as Learning Management Systems where the lecture presentations are arranged into study units together with topical assignments and quizzes. Table 1 provides short summaries of the HCI courses in March 2013. The information of the two MOOCs is based on their web pages [START_REF] Dix | HCI Course[END_REF][START_REF] Klemmer | Human-Computer Interaction[END_REF]. All these courses are open in such a way that the educators cannot assume any specific learner profile. Even CUX is open since it is offered to all international exchange students who arrive at our university and sign up to take it. No background studies are required. This way, it is open to all interested, but in a much smaller scale. The students need to have study rights at our university to enroll.

All courses depend on student activity during the course weeks. For CUX only students passing the final examination get university credits. The examination is a closed book exam arranged online, but in a controlled environment where the students' identity can be verified. This is a key issue for MOOCs where cheating is a concern [START_REF] Daniel | Making Sense of MOOCs: Musings in a Maze of Myth, Paradox and Possibility[END_REF].

In the Stanford course, students were expected to give feedback on each others' design assignments. Assessing the quality of creative work and user interface designs is a challenge to students and educators alike [START_REF] Cooper | Reflections on Stanfords's MOOCs[END_REF], and it requires carefully designed assessment rubrics [START_REF] Kulkarni | Learning Design Wisdom by Augmenting Physical Studio Critique with Online Self-Assessment[END_REF] that need to be adapted to each assignment.

While online courses bring flexibility of time and place, time management needs special attention. In all three courses, time management has proven difficult. If the schedule is set too tight, there will be drop-outs. For many MOOC students, the HCI course is an extra-curricular course, and other obligations are more pressing at times. Time management is especially challenging in those courses where the students are expected to work together, for instance, to discuss something together in small online groups. Some students have moved on already while the others are just beginning their work on the topic, which might be a reason for the rather small number of discussions in the currently ongoing HCICourse [START_REF] Dix | HCI Course[END_REF]. The deadlines of assignments need to be announced at the outset of the course so that it is possible to plan ahead.

The course administrators would benefit from knowing who will finish the task at some point and who in time, and who will drop out without submitting any answer. This is one area of empirical research in the Stanford course [START_REF] Cheng | Tools for predicting drop-off in large online classes[END_REF]. Student profiling can support learner-centered design of the whole VLE [START_REF] Notess | Usability, User Experience, and Learner Experience[END_REF].

Videos as Study Material

Next we look at how the learning units (compare with Table 1) are delivered. All three HCI courses offer many short (typically 10-20 minute) recordings where the educator gives a lecture with slides and demo material. Only two of these courses include video recording of the educator in front of a camera. The quality of the recordings varies -seemingly simple issues such as where the video camera and speaker's monitor are located matter in the end result (Figure 1). In CUX, the whole course contains only one welcoming video of the educator, to give a face to the voice. All other lecture slides contain audio only. This was an intentional design decision at the outset of building the course for two reasons. Videos of talking heads do not seem to provide added value content-wise. Changing the audio by re-recording is much easier than editing video content.

The personality of the educator comes through in the video to the students, and body language enhances the message. The appearance and informal outfit give a more lively experience than was achieved in early recorded lectures, such as those by Day and Foley [START_REF] Day | Evaluating a Web Lecture Intervention in a Human-Computer Interaction Course[END_REF]. The slides can be showing on a background screen, as a background window where the video overlay of the presenter is inserted, or as the single video window. This makes the lecture more dynamic than it would be if showing just the face or upper body of the lecturer and a static arrangement of the scene. A live video stream, if not focusing on the lecturer's face, also enables showing demos and live sketching or scribbling. These are valuable assets in teaching about interaction. In Classroom 2000 [START_REF] Abowd | Teaching and Learning as Multimedia Authoring: The Classroom 2000 Project[END_REF], the lectures were captured with audio and scribbles made during the lecture became a part of the material. In this way, some of the classroom interaction was delivered to students who could not take part. Fortunately, plenty of online video material exists in HCI in open access repositories2 that can be directly linked to from the course platforms. This is done extensively in the HCICourse [START_REF] Dix | HCI Course[END_REF] and in CUX, too.

Study Methods: Making Notes, Working on Assignments

Compared to normal class long recordings of the Classroom 2000 [START_REF] Abowd | Teaching and Learning as Multimedia Authoring: The Classroom 2000 Project[END_REF], the MOOC videos are short, but still they seem separated from the exercises. A more directly interactive learning session by interleaving video and quizzes would enable faster learning cycles. In HCI education, "theory" and application interleave [START_REF] Day | Evaluating a Web Lecture Intervention in a Human-Computer Interaction Course[END_REF]. One of the first feedback messages in CUX was that a student asked for the PDF versions of the lecture presentation material used in the recordings to support notetaking while watching the presentations. Some students study by scribbling notes on the presentation [START_REF] Abowd | Teaching and Learning as Multimedia Authoring: The Classroom 2000 Project[END_REF]. The video recordings do not allow for this kind of capture of one's own content in the right context, and making notes on a fast-paced video lecture where only some parts of each slide are explained in depth would be difficult.

In the HCICourse [START_REF] Dix | HCI Course[END_REF], a student can make bookmarks, build lists of items, and make notes on various things. There is also a possibility to add discussion threads to any type of resource or assignment of the course, such as the video in Figure 1. This way the student can ask for clarifications or comment on the presentation in context. However, spreading the questions and answers into several locations makes it more difficult to see the big picture and where the action is. This resembles the networking ideal of the first MOOC [START_REF] Cormier | What is a MOOC? Video available at[END_REF]: study materials and information do not need to reside in one web platform but can be distributed, and the wisdom of the crowd is utilized in assessing the value of the materials.

Collaboration between peers is often considered valuable in fostering learning [START_REF] Kester | Designing Support to Facilitate Learning in Powerful Electronic Learning Environments[END_REF]. CUX does not support peer interaction elsewhere but in the two discussion forums and the Comments block that is available in our Moodle 2.3 installation. To our surprise, the students did not use the forums for discussion, but the informal Comment block was often used for pointing out interesting links to peers.

Most assignments in CUX include quiz questions, such as in Figure 2. However, to enhance deep learning, in most occasions we asked for explanations and reasons for the answer the student gave. Often in HCI the answer is "It depends…"! Fig. 2. A screen shot of a quiz page in CUX. The original car picture is from [START_REF] Nielsen | The Usability Engineering Lifecycle[END_REF].

Before giving out the two design assignments of CUX we asked CUX participants about their desire to collaborate. The opinions were nearly unanimous: 81% of the respondents accept and are happy with individual study as the course study method. However, they want tutor feedback on their answers, so that they know if their answers are correct or not. Providing such feedback for design assignments and open questions (such as the question posed in Figure 2) is not trivial in massive courses, but appropriate for the small scale CUX. In the Stanford course that applies many extensive assignments, the educators have worked on assessment rubrics that enable student self-assessment of their assignment submissions [START_REF] Martin | Will Massive Open Online Courses Change How We Teach?[END_REF]. The early results point out that the students improve in their assessment skills so that their assessments more accurately match assessments done by staff members. Working on the rubrics and assessments also improves teaching and makes the grading process transparent.

6

Discussion and Future Work

Instead of adopting a MOOC in full, a better pedagogy might result from combining the open access materials somehow to classroom tuition. One of the recurring themes with these open access video-based lectures is "flipped classrooms" [START_REF] Martin | Will Massive Open Online Courses Change How We Teach?[END_REF]: the students are expected (and motivated [START_REF] Day | Evaluating a Web Lecture Intervention in a Human-Computer Interaction Course[END_REF]) to watch a recorded lecture video and work on relevant learning tasks already before class. This way the class time would enable more interaction with the students instead of the lecturing [START_REF] Cooper | Reflections on Stanfords's MOOCs[END_REF].

While the three HCI courses we compared differ in their methods quite a lot, they share similar challenges: keeping up motivation and interest, enabling time management, building on the principles of HCI and educating the students about our field.

The feedback from CUX participants has been encouraging. The online course format has been found good: the students enjoy being able to study when they have suitable time slots, control their own pace and plan ahead for the coming weeks. Nearly all who worked on the assignments also passed the examination -less than 10 percent were drop-outs. Many students said that they enjoyed sketching and learned most from the design tasks, but we noticed that the designs in some cases were not so good. It is evident that the feedback on their design ideas is essential for learning.

Our initial experiences also point out areas of improvement. Though the lecture presentations are shorter than in-class lectures on the same topics, they miss much of the dynamic interaction between the educator and the students. A shorter linkage between the "theory" of the lecture and the practical applications in the assignments would be needed to provide more reflection on the topics discussed in the lecture.

It is important to collect and share experiences of MOOCs in general and HCI MOOCs in particular. Teaching and study methods are evolving, and materials and solutions developed for MOOCs can help local efforts like ours. All in all, CUX has so far served its purpose well. Although the development effort was extensive, it provides a platform for individual study throughout the year, and separate course instances can be offered repeatedly at a low cost per instance.

Fig. 1 .

 1 Fig. 1. Example screen shots of HCI course videos by Alan Dix (left) and Scott Klemmer (right), presented with their permission.

Table 1 .

 1 Course Comparison Table

		Stanford HCI Course [13] HCICourse [8]	CUX
	Aimed at	Beginners	Beginners	Beginners
	Goal	Build design skills	Deliver free and open	Introduce HCI principles
			access info in HCI	and key concepts
	Units/	1: Introduction	1: Introduction	1: Welcome
	Weeks/	2: Needfinding	2: Interaction design	2: Humans: some basics
	Main topics	3: Rapid prototyping	3: Human perception	3: User-Centered Design
		4: Direct manipulation	and cognition	4: WIMP and GUI
		5: Heuristic evaluation	4: Emotion and experi-	5: Post-WIMP
		6: Representations	ence	6: Future
		7: Visual design	5: Implementation
		8: Information design	6: Evaluation
		9: Designing experiments	(+ additional four units
		10: Running experiments	an "advanced course")
	Types of	Quizzes	Individual exercises and	Quizzes
	assignments	Design assignments	group discussions,	Structured assignments
		Peer evaluation and feed-	posted in online discus-	Design assignments
		back	sion threads
	University	Varies by location 1 ;	No.	Yes.
	credits	Statement of Accom-
		plishment provided.
	Completion Various completion levels	Activity-based (answer	Activity in submitting
		Apprentice track, Studio	quality not assessed)	assignments, quality of
		track or Studio Practicum	OpenBadge.	assignments; Exam

For instance, the Stanford HCI course that started in April

can be taken for credit at the University of Helsinki, see http://www.cs.helsinki.fi/node/72025

A couple of the first online HCI video repositories: http://hccedl.cc.gatech.edu/, http://www.open-video.org/, http://www.cs.umd.edu/hcil/pubs/video-reports.shtml, http://www.acm.org/uist/archive/

Acknowledgements. Professors Dix and Klemmer are thanked for feedback on an early version of this paper. Ville Hämäläinen, CUX teaching assistant, was indispensable in running the course for the first time, and we thank the CUX course participants for filling in many questionnaires providing us with a glimpse of the experience.


Fulvio Lizano
email: fulvio@cs.aau.dk

Maria Marta Sandoval
email: msandova@una.cr

Anders Bruun
email: bruun@cs.aau.dk

Jan Stage
email: jans@cs.aau.dk

Anders Brunn

Usability Evaluation in a Digitally Emerging Country: A Survey Study

Keywords: Usability evaluation, advantages, obstacles, digitally emerging countries

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Usability evaluation is a relevant and strategic activity in software projects [START_REF]SWEBOK Guide to the Software Engineering Body of Knowledge[END_REF]. For the user, a high level of usability in a software system is important [START_REF] Lindgaard | Usability Testing: What Have We Overlooked?[END_REF]. For the user organization, usability is important because it can provide benefits such as increased sales, productivity, lower training costs and reduced technical support for users [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]. Previous studies of the perception of usability evaluation have been focused on obstacles and advantages. Two specific cases have identified obstacles in software organizations. The first one was a survey in Northern Jutland, Denmark [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF] (known in this paper as the "D-Study") and the second, which replicated the first, was made in Southern Italy [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF] (known in this paper as the "I-Study"). The D-Study identified several obstacles to increased application of usability evaluation, e.g. developer mindset, resource demands, lack of understanding, customer participation, conducting tests and test participants [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]. In the case of the I-Study, major obstacles identified were resource demands, no suitable methods, developers' mindset and user availability. In addition, this study identified advantages of usability evaluation such as quality improvement, the users' satisfaction, resource saving and competitiveness [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF].

These facts, together with other problems found in digitally advanced countries [START_REF]Mobile usability testing Problems and solutions[END_REF][START_REF] Ferre | Obstacles for the Integration of HCI Practices into Software Engineering Development Processes[END_REF][START_REF] Gulliksen | Making a difference: a survey of the usability profession in Sweden[END_REF][START_REF] Juristo | How to integrate usability into the software development process[END_REF][START_REF] Muzaffar | Usability Aspects in Pervasive Computing: Needs and Challenges[END_REF][START_REF] Rosenbaum | A toolkit for strategic usability: results from workshops, panels, and surveys[END_REF][START_REF] Seffah | The obstacles and myths of usability and software engineering[END_REF], can be visualized, as a whole, in a view formed by several dimensions of types of actors (e.g. users or clients, software developers, and organizations) plus types of facts (e.g. facts related to understanding, advantages and obstacles of usability evaluation) This is a way to put into context the real implications for usability evaluation in digitally advanced countries. In Table 1 we present the distribution of these findings into the cited dimensions (some references are related with different dimensions at once). Table 1. Main findings related to usability evaluation.

Types of facts (related to…) Types of actors

Understanding of usability evaluation

Advantages of usability evaluation

Obstacles of usability evaluation

Users / Customers

 User involve- ment[1,2]  Customer involvement[2]
 User satisfaction [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF]  Test participants [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]  Customer participation [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]  User availability [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF] Software developers

 Developer mindset[2]  Developer mindset[1]
 Lack of trained eng.usab/HCI [START_REF] Rosenbaum | A toolkit for strategic usability: results from workshops, panels, and surveys[END_REF]  Personal developers tools [START_REF] Seffah | The obstacles and myths of usability and software engineering[END_REF] Organizations

 Functionality[2]  Problem/task solving[2]  Possibility test[2]  Usability evalua- tion[1]  Usability defini- tion[1]  Accessibility test[1]  Qlty.improve ment[1]  Competitive- ness[1]  Resource saving[1]
 Lack of understanding [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF][START_REF] Rosenbaum | A toolkit for strategic usability: results from workshops, panels, and surveys[END_REF][START_REF] Seffah | The obstacles and myths of usability and software engineering[END_REF]  Resource demands [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]  Conducting tests [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]  No suitable methods [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF]  Resource demands [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF][START_REF] Rosenbaum | A toolkit for strategic usability: results from workshops, panels, and surveys[END_REF]  Resistance to UCD-Usability [START_REF] Rosenbaum | A toolkit for strategic usability: results from workshops, panels, and surveys[END_REF]  Lack of comms. of impact [START_REF] Rosenbaum | A toolkit for strategic usability: results from workshops, panels, and surveys[END_REF]  Lack coupling UCD & S-Dev l.cycle [START_REF] Seffah | The obstacles and myths of usability and software engineering[END_REF]  Gap SD & usability [START_REF] Seffah | The obstacles and myths of usability and software engineering[END_REF]  Edu. lack coupling (SD&usab.) [START_REF] Seffah | The obstacles and myths of usability and software engineering[END_REF]  Lack of respect and support [START_REF] Gulliksen | Making a difference: a survey of the usability profession in Sweden[END_REF]  Limited description HCI in SE [START_REF] Ferre | Obstacles for the Integration of HCI Practices into Software Engineering Development Processes[END_REF]  Strong differences HCI & SE [START_REF] Juristo | How to integrate usability into the software development process[END_REF]  Lack of "usability culture" [START_REF]Mobile usability testing Problems and solutions[END_REF][START_REF] Muzaffar | Usability Aspects in Pervasive Computing: Needs and Challenges[END_REF] In this paper, we present the results of a study that explored the application of usability evaluation in software development organizations in a digitally emerging country. The aim of our study was to explore the understanding of the usability evaluation concept, their advantages and obstacles. Our interest was identifying similarities, differences and patters that could enhance the application of usability evaluation in other digitally emerging countries. This explains why we will present our results and compare them to other studies, especially with the D-Study and the I-Study.

METHOD

Settings

We conducted a survey at software development companies in Costa Rica. According The Global Information Technology Report 2012 (World Economic Forumwww.weforum.org/gitr), Costa Rica is a digitally emerging country ranked in the 58 position of the Networked Readiness Index (NRI). Costa Rica has a NRI of 4 in a 1to-7 scale.

Participants and procedure

The study has involved companies that could potentially conduct usability evaluations and in addition met the specific criteria, e.g. located in a specific geographical area (Costa Rica), that develop software or hardware with graphical user interfaces, that develop software for customers or for internal use and that employ more than a single person. Initial set of participants was made using the list of organizations affiliated to the Chamber of Information and Communication Technology -CAMTIC, by its Spanish acronym (www.camtic.org) (148 organizations). This organization is open to any IT organization of Costa Rica and was founded in 1998. Because CAMTIC is open to a broad range of IT companies, we decided to filter the original list obtaining a final list of 35 organizations. Our survey was completed by 26 organizations (74%). The average number of years of operation of the organizations participating in the study was 11. The average of age of the persons, who filled the questionnaire, was 39. 15% of them were females. All these companies were located at the central valley of Costa Rica (the most developed zone of Costa Rica). The organizations had this distribution on number of employees: 58% (1-10), 19% (11-50) and 23% (51-250). In order to find the person most appropriate to participate in the study, we contacted every company personally by phone in order to enquire who could provide an opinion that could reflect the position of the company in the survey. These persons received an electronic token to access the online survey which was active for 4 weeks.

Data collection and analysis

The questionnaire used in the study contained several parts. The main parts were: demographic and general information, products/services provided by the organization, methodology used to develop software applications, understanding of the usability evaluation concept, and obstacles and advantages of the application of usability evaluation. We used a combination of open-closed questions was used. The aim of open questions was to permit participants to express themselves in their own words. Closed questions were used in order to allow to them to reconfirm data previously provided. We used different analytical approaches to analyze the data generated in the closed and open questions. A quantitative analysis was used on the closed questions, and grounded theory by Strauss and Corbin [START_REF] Strauss | Basics of qualitative research[END_REF] was used for the analysis of the open questions.

RESULTS

We were interested in exploring the understanding of the concept of usability evaluation in the software development organizations. Our results allowed us to identify several categories of understanding that the organization have about this concept. In order to verifying what the organizations had understood by usability evaluation, after provide their definition of usability evaluation, we showed them a definition of usability evaluation based on the ISO-9241 standard. Next, we asked them if they made usability evaluations in their companies in accordance with this ISO definition and the strategy followed by them to do it. The participants basically reported two categories of strategy: internal or external conduction of usability evaluation. However, a relevant number of participants reported do not conduct usability evaluations at all. Finally, some participants did not provide a response for this enquiry. In Table 2, we present these results. On the other hand, following the methodological approach established in our method, we identified the main advantages and obstacles for applying usability evaluation. First, using an open question we identified advantages and obstacles of the application of usability evaluation. Some participants offered more than one advantage/obstacle and others did not respond. The results were grouped in different categories of advantages/obstacles. In the case of the advantages, main results were product quality (35%), user acceptance (32%) and no advantages (32%). The main obstacles detected were users (22%), software design (19%), software development method (15%), costs (11%), software developers (4%) and no obstacles (30%). The organizations which reported do not conduct usability evaluation in their process, were the ones which had not found advantages or obstacles.

In order to complement the previous results, we presented to the participants with a list of common advantages and obstacles of usability evaluation. The participants could select more than one option. Results are showed in Table 3. These results represent some of the main facts related to usability evaluation in digitally emerging countries. To facilitate a comparison of these facts with the ones presented in digitally advanced countries, we present them in a similar way as we did at table 1. Thus, as it is possible to see in Table 4, users, customers and software developers are not presented into the understanding of usability evaluation, by the software development organizations at the digitally emerging countries. In addition, our results suggest a weak visualization of advantages and obstacles in the same context. Similar to the digitally advanced countries, at digitally emerging countries it is possible to find more facts related to the understanding, advantages and obstacles of usability evaluation, in the context of the organizations.

DISCUSSION

Our results suggest a relatively good understanding of the understanding of the usability evaluation concept, including some similarities to previous studies, e.g. in some aspects of the notion of usability [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF], and in usability matters as a whole, specifically in some responses related to user involvement [START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]. The good understanding about the definition of usability evaluation was obtained from organizations which conduct usability evaluation internally. This practical experience supported this better understanding. This is even more evident when we analyze the reasons given by those organizations that do not conduct usability evaluations (19%). Although the distribution of their understanding is uniform in the different categories of understanding, these participants provided opinions that are clear signals of a misunderstanding about usability evaluation, e.g. "in open source software projects you do not need usability evaluations" or "some projects do not require usability evaluations" and "a software project only needs functional tests". Here, we can see and excellent example of what the lack of "usability culture" is [START_REF]Mobile usability testing Problems and solutions[END_REF][START_REF] Muzaffar | Usability Aspects in Pervasive Computing: Needs and Challenges[END_REF].

In the case of advantages, our results are fully in agreement with the I-Study [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF]. However, in the case of the obstacles, our study found very interesting results. The 'user' was identified as one of the most relevant obstacle. This was emphasized by participants who conduct usability evaluations internally, which makes this result conclusive. Both the D-Study and I-Study also identified this obstacle but with a lower level of importance [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF][START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]. This finding allows us to notice that in a digitally emerging country, participation of users in usability evaluation seems to be particularly challenging. Consistently with the D-Study and the I-Study, our study confirmed obstacles related to resource demands and software developers' mindset [START_REF] Ardito | Usability Evaluation: a survey of software development organizations[END_REF][START_REF] Bak | Obstacles to Usability Evaluation in Practice: A Survey of Software Development Organizations[END_REF]. It is interesting to notice that the level of relevance given to this last obstacle has changed across the D-Study, the I-Study and our study. This obstacle was very important in the D-Study. In the I-Study, its relevance was lower. Finally, in our study this obstacle is the last one mentioned by the participants. This change could, initially, reinforce our perception of a positive change in the lack of a "usability culture". However, other results obtained in the closed questions seem to offers contradictory results. In this case, the most important obstacle selected by participants was related to the software developers' mindset problem. These different levels of relevance are not necessarily a contradiction. Actually, the fact that this obstacle was cited twice in our study allow us to conclude that this matter continues been one of the most recognized obstacles against increased use of usability evaluation. The second obstacle identified in this part of our study is related to resource demands, which is not surprising.

In addition, there are new obstacles that were identified in our study. First obstacle is related to problems in the design process of the software, which subsequently could hinder conduction of usability evaluations. Second, a new obstacle was identified in some problems related to the software development method. This obstacle was identified by the I-Study in 2011 but not by the D-Study in 2008. Here it is possible to observe a change of tendency in the lack of "usability culture", into those organizations that have practical experience; an alternative view about the new obstacles, which is more connected to the software development process, seems to emerge to reduce some problems such as the confusion, the lack of coupling and some gaps between SE and HCI [START_REF] Seffah | The obstacles and myths of usability and software engineering[END_REF].

In digitally advanced countries the main facts related to understanding, advantages and obstacles to conduct usability evaluation are more connected with methodology and the organization (see Table 1). Users, customers and software developers have a lower visualization. More remarkable is the fact that software developers are not presented at all in such dimensions. Only in the case of the obstacles, it is possible to find more facts related to users, customers and developers.

In digitally emerging countries, this situation seems no to be better (see Table 4). Into the understanding of usability evaluation, the users, the clients and the developers are excluded at all. Only a limited number of advantages were noticed for users and clients, none related to developers.

We think that our study provide interesting results that can be extended to other similar contexts. The digitalization level and other human and economical indicators are pretty similar to others countries in the same region, e.g. Ecuador, Trinidad & Tobago, Panama, Peru, Brazil and The Bolivarian Republic of Venezuela. The average on Networked Readiness Index (NRI) in these countries (including Costa Rica) is 3,71 (SD=0,32), the mean value for the GNI per capita in PPP terms (constant 2005 international $) is 12,051 (SD= 4,740), the average of expected years of schooling is 9,05 (SD=2,21), the mean value for expectancy of life (years) is 74,81 (SD= 2,79). Main differences are related to population and territorial extension. Considering all these facts, the context studied in our research can be considered a good referent about how usability evaluation is conducted in other digitally emerging countries.

Conclusion and future works

In this research we have explored the application of usability evaluation in software development organizations in the digitally emerging countries. To accomplish this, we conducted a questionnaire survey with 26 participating software development organizations. As part of our research, our findings were contrasted with results from similar studies in digitally advanced countries. The aim of our study was to obtain valuable feedback that could orientate future enhancement actions of application of usability evaluation in digitally emerging countries.

Our study found a relatively acceptable conduction of usability evaluation in digitally emerging countries, embodied by a fairly clear understanding about the meaning of usability evaluation and similar advantages and obstacles to the found in other digitally advanced countries. In addition, our research has identified new obstacles such as the users' behavior and problems related to the design of the software. These new obstacles can offer to HCI theory a complementary perspective on usability evaluation. These new findings seem to imply a decreasing tendency in the lack of "usability culture". However, our results do not permit strong conclusions about this matter as it was not a focus of our study.

However, any improvement of conduction of usability evaluation at the context studied must necessarily go through an empowerment process of users, clients and software developers, as main actors in such processes. In the case of users and clients, reasons to do that are more than evident; in some sense, these actors are a main cornerstone of theory of HCI. For developers, this strategy should help continuing improvement of some well studied problems, e.g. confusion, the lack of coupling and the gaps between software engineering and HCI. Future works could focus on exploring specific forms to enhance and increase the use of usability evaluations in software development organizations located in digitally emerging countries.

Table 2 .

 2 Distribution of the strategy used to conduct usability evaluation related to the understanding of the concept of usability evaluation

			Category of understanding (In terms of…)
	Strategy used to conduct	Usability	Usability evalu-	Another kind of	No	Percent
	usability evaluation	concept	ation concept	testing	response
	Internally	4	8	4		62%
	Externally		1	2		12%
	No Usab.evaluation	1	2	2		19%
	No response				2	8%
	Percent	19%	42%	31%	8%

Table 3 .

 3 Advantages and obstacles provided through closed questions.

	Advantages.	#	P	Obstacles	#	P
	User satisfaction	19	39%	Recruitment of test partic-	9	20%
				ipants
	Quality improvement	18	37%	Conduct test / no method 6	13%
	Competitiveness	5	10%	Developer mindset	17	38%
	Resource saving	6	12%	Resources demands	8	18%
	Other	1	2%	Other	5	11%
	Total	49			45

Table 4 .

 4 Summary of results.

					Types de facts (related to…)
	Types	of	Understanding	of	Advantages	of	Obstacles of usability evaluation
	actors		usability evaluation	usability evaluation
	Users / Cus-			 User acceptance		 User
	tomers				 User satisfaction	 Test participants
	Soft.Dev.						 Software developers mindset
							 Software design
	Organiza-tions		 Usability concept  Usability evalua-tion concept  Other test		 Product quality  Qlty improvement  Competitiveness  Resource saving	 Software development method  Costs  Usability evaluation conduction.  No usability evaluation method

Acknowledgments

The research behind this paper was partly financed by Universidad Nacional (Costa Rica), MICIT (Costa Rica), CONICIT (Costa Rica), and the Danish Research Councils (grant number 09-065143).