Showing papers in "International Journal of Human-computer Studies \/ International Journal of Man-machine Studies in 2006"

Understanding e-learning continuance intention: An extension of the Technology Acceptance Model

Abstract: Based on the expectancy disconfirmation theory, this study proposes a decomposed technology acceptance model in the context of an e-learning service. In the proposed model, the perceived performance component is decomposed into perceived quality and perceived usability. A sample of 172 respondents took part in this study. The results suggest that users' continuance intention is determined by satisfaction, which in turn is jointly determined by perceived usefulness, information quality, confirmation, service quality, system quality, perceived ease of use and cognitive absorption.

Current practice in measuring usability: Challenges to usability studies and research

Abstract: How to measure usability is an important question in HCI research and user interface evaluation. We review current practice in measuring usability by categorizing and discussing usability measures from 180 studies published in core HCI journals and proceedings. The discussion distinguish several problems with the measures, including whether they actually measure usability, if they cover usability broadly, how they are reasoned about, and if they meet recommendations on how to measure usability. In many studies, the choice of and reasoning about usability measures fall short of a valid and reliable account of usability as quality-in-use of the user interface being studied. Based on the review, we discuss challenges for studies of usability and for research into how to measure usability. The challenges are to distinguish and empirically compare subjective and objective measures of usability; to focus on developing and employing measures of learning and retention; to study long-term use and usability; to extend measures of satisfaction beyond post-use questionnaires; to validate and standardize the host of subjective satisfaction questionnaires used; to study correlations between usability measures as a means for validation; and to use both micro and macro tasks and corresponding measures of usability. In conclusion, we argue that increased attention to the problems identified and challenges discussed may strengthen studies of usability and usability research.

The effects of post-adoption beliefs on the expectation-confirmation model for information technology continuance

Abstract: The expectation-confirmation model (ECM) of IT continuance is a model for investigating continued information technology (IT) usage behavior. This paper reports on a study that attempts to expand the set of post-adoption beliefs in the ECM, in order to extend the application of the ECM beyond an instrumental focus. The expanded ECM, incorporating the post-adoption beliefs of perceived usefulness, perceived enjoyment and perceived ease of use, was empirically validated with data collected from an on-line survey of 811 existing users of mobile Internet services. The data analysis showed that the expanded ECM has good explanatory power (R^2=57.6% of continued IT usage intention and R^2=67.8% of satisfaction), with all paths supported. Hence, the expanded ECM can provide supplementary information that is relevant for understanding continued IT usage. The significant effects of post-adoption perceived ease of use and perceived enjoyment signify that the nature of the IT can be an important boundary condition in understanding the continued IT usage behavior. At a practical level, the expanded ECM presents IT product/service providers with deeper insights into how to address IT users' satisfaction and continued patronage.

The role of moderating factors in user technology acceptance

Abstract: Along with increasing investments in new technologies, user technology acceptance becomes a frequently studied topic in the information systems discipline. The last two decades have seen user acceptance models being proposed, tested, refined, extended and unified. These models have contributed to our understanding of user technology acceptance factors and their relationships. Yet they have also presented two limitations: the relatively low explanatory power and inconsistent influences of the factors across studies. Several researchers have recently started to examine the potential moderating effects that may overcome these limitations. However, studies in this direction are far from being conclusive. This study attempts to provide a systematic analysis of the explanatory and situational limitations of existing technology acceptance studies. Ten moderating factors are identified and categorized into three groups: organizational factors, technological factors and individual factors. An integrative model is subsequently established, followed by corresponding propositions pertaining to the moderating factors.

A longitudinal investigation of continued online shopping behavior: An extension of the theory of planned behavior

Abstract: The purpose of this study is to propose an extended model of Theory of Planned Behavior (TPB) by incorporating constructs drawn from the model of Expectation Disconfirmation Theory (EDT) and to examine the antecedents of users' intention to continue using online shopping (continuance intention). Prior research has demonstrated that TPB constructs, including attitude, subjective norm, and perceived behavioral control, are important factors in determining the acceptance and use of various information technologies. These factors, however, are insufficient to explain a user's continuance intention in the online shopping context. In this study we extended TPB with two EDT constructs-disconfirmation and satisfaction-for studying users' continuance intention in the online shopping context. By employing longitudinal method with two-stage survey, we empirically validated the proposed model and research hypotheses.

Are physically embodied social agents better than disembodied social agents?: The effects of physical embodiment, tactile interaction, and people's loneliness in human-robot interaction

Abstract: Two experiments were conducted to investigate the effects of physical embodiment in human-agent interaction. Experiment 1 (N=32) shows positive effects of physical embodiment on the feeling of an agent's social presence, the evaluation of the agent, the assessment of public evaluation of the agent, and the evaluation of the interaction with the agent. A path analysis reveals that the feeling of the agent's social presence mediates the participants' evaluation of the social agent. Experiment 2 (N=32) shows that physical embodiment with restricted tactile interaction causes null or even negative effects in human-agent interaction. In addition, Experiment 2 indicates that lonely people feel higher social presence of social agents, and provide more positive social responses to social agents than non-lonely people. The importance of physical embodiment and tactile communication in human-agent interaction and the diverse role of social robots, especially for the lonely population, are discussed.

Evaluating the consistency of immediate aesthetic perceptions of web pages

Abstract: Two experiments were designed to replicate and extend [Lindgaard et al.'s, 2006. Attention web designers: you have 50 ms to make a good first impression! Behaviour and Information Technology 25(2), 115-126] findings that users can form immediate aesthetic impression of web pages, and that these impressions are highly stable. Using explicit (subjective evaluations) and implicit (response latency) measures, the experiments demonstrated that, averaged over users, immediate aesthetic impressions of web pages are remarkably consistent. In Experiment 1, 40 participants evaluated 50 web pages in two phases. The average attractiveness ratings of web pages after a very short exposure of 500 ms were highly correlated with average attractiveness ratings after an exposure of 10 s. Extreme attractiveness evaluations (both positive and negative) were faster than moderate evaluations, landing convergent evidence to the hypothesis of immediate impression. The findings also suggest considerable individual differences in evaluations and in the consistency of those evaluations. In Experiment 2, 24 of the 50 web pages from Experiment 1 were evaluated again for their attractiveness after 500ms exposure. Subsequently, users evaluated the design of the web pages on the dimensions of classical and expressive aesthetics. The results showed high correlation between attractiveness ratings from Experiments 1 and 2. In addition, it appears that low attractiveness is associated mainly with very low ratings of expressive aesthetics. Overall, the results provide direct evidence in support of the premise that aesthetic impressions of web pages are formed quickly. Indirectly, these results also suggest that visual aesthetics plays an important role in users' evaluations of the IT artifact and in their attitudes toward interactive systems.

Computer use has no demonstrated impact on the well-being of older adults

Abstract: Technology is frequently presented as a panacea for the support needs of the ageing population, based in part upon the commonly cited assertion that computer and internet use has an empirically verified positive effect on the well-being of older people. In this paper we review the studies that this assertion is based on and conclude that they do not support it. While the original studies rarely make unsupportable claims, the secondary literature which cites them is frequently very misleading; limitations include, failure to distinguish between the effects of training/support and computer use; misattributing causality; inappropriately generalising results from a different population.

Weblog success: Exploring the role of technology

Abstract: Weblogs have recently gained considerable media attention. Leading weblog sites are already attracting millions of visitors. Yet, success in the highly competitive world of weblogs is not easily achieved. This study seeks to explore weblog success from a technology perspective, i.e. from the impact of weblog-building technology (or blogging tool). Based on an examination of 126 highly successful weblogs tracked over a period of 3 months, we categorized weblogs in terms of popularity rank and growth, and evaluated the relationship between weblog success (in terms of popularity) and technology use. Our analysis indicates that weblog success is associated with the type of blogging tool used. We argue that technology characteristics affect the presentation and organization of weblog content, as well as the social interaction between bloggers, and in turn, affect weblog success or popularity improvement. Based on this analysis, we propose a techno-social success model for weblogs. This model postulates that a weblog's success is mainly associated with its ability to provide value for its users and readers at the content, the technology, and the social levels.

The influence of information presentation formats on complex task decision-making performance

Abstract: Understanding the influence of information presentation formats on decision-making effectiveness is an important component of human-computer interaction user interface design. The pervasive nature and ease of use associated with information display formats in wideiy used personal productivity software suggests that decision-makers are likely to create and/or use documents with both text-based and more visually oriented information displays. Past research has investigated the role of these displays on simple decision tasks; however, empirical research has not extended to more complex tasks, more comparable to the types of tasks decision-makers face every day. Results from the empirical analysis suggest that the relationship between information presentation format and decision performance is moderated by the complexity of the task. More specifically, spatial formats result in superior decision accuracy for simple- and complex-spatial tasks and faster decision time for all tasks except the complex-symbolic task where graphs and tables result in equivalent decision time.

A framework for understanding trust factors in web-based health advice

Abstract: Trust is a key factor in consumer decisions about website engagement. Consumers will engage with sites they deem trustworthy and turn away from those they mistrust. In this paper, we present a framework for understanding trust factors in web-based health advice. The framework is derived from a staged model of trust and allows predictions to be made concerning user engagement with different health websites. The framework is then validated via a series of qualitative, longitudinal studies. In each study, genuine consumers searched online for information and advice concerning their specific health issue. They engaged in free searching and were directed towards sites previously reviewed using the framework. Thematic analysis of the group discussions provided support for the framework and for the staged model of trust wherein design appeal predicted rejection (mistrust) and credibility of information and personalization of content predicted selection (trust) of advice sites. The results are discussed in terms of the merits of the framework, its limitations and directions for future work.

Unsupervised learning techniques for fine-tuning fuzzy cognitive map causal links

Abstract: Fuzzy Cognitive Maps (FCMs) constitute an attractive knowledge-based methodology, combining the robust properties of fuzzy logic and neural networks. FCMs represent causal knowledge as a signed directed graph with feedback and provide an intuitive framework which incorporates the experts' knowledge. FCMs handle available information and knowledge from an abstract point of view. They develop behavioural model of the system exploiting the experience and knowledge of experts. The construction of FCMs is based mainly on experts who determine the structure of FCM, i.e. concepts and weighted interconnections among concepts. But this methodology may not be a sufficient model of the system because the human factor is not always reliable. Thus the FCM model of the system may requires restructuring which is achieved through adjustment the weights of FCM interconnections using specific learning algorithms for FCMs. In this article, two unsupervised learning algorithms are presented and compared for training FCMs; how they define, select or fine-tuning weights of the causal interconnections among concepts. The implementation and results of these unsupervised learning techniques for an industrial process control problem are discussed. The simulations results of training the process system verify the effectiveness, validity and advantageous characteristics of those learning techniques for FCMs.

A conceptual foundation of the thinkLet concept for Collaboration Engineering

Abstract: Organizations increasingly use collaborative teams in order to create value for their stakeholders. This trend has given rise to a new research field: Collaboration Engineering. The goal of Collaboration Engineering is to design and deploy processes for high-value recurring collaborative tasks, and to design these processes such that practitioners can execute them successfully without the intervention of professional facilitators. One of the key concepts in Collaboration Engineering is the thinkLet-a codified facilitation technique that creates a predictable pattern of collaboration. Because thinkLets produce a predictable pattern of interactions among people working together toward a goal they can be used as snap-together building blocks for team process designs. This paper presents an analysis of the thinkLet concept and proposes a conceptual object model of a thinkLet that may inform further developments in Collaboration Engineering.

Design of animated pedagogical agents-A look at their look

Abstract: A well-established effect of animated agents in educational and other contexts is their potential to motivate and engage. ''Increased motivation in users'' is also one of the more frequent answers given to the question, ''What is gained by adding an animated pedagogical agent to an intelligent tutoring system?'' To further develop and exploit this potential, there are, however, several issues that need to be resolved. In this article we discuss the visual form and look of animated pedagogical agents. A survey is presented of how the area is approached (and, in particular, not approached) in research on animated pedagogical agents. Two possible reasons are proposed as to why visual form and look are so little addressed are also proposed. We also propose and discuss some key aspects of look that merit a systematic approach in future research. The main thesis of the paper is that users' visuo-aesthetic experience of animated pedagogical agents is too important with respect to the goals to motivate and engage, to be treated as a secondary issue. We do not deny that there are other pressing and fundamental issues that need to be solved, such as those concerning the content of the support and the competence level of agents, as well as various design elements that can contribute to making animated agents lifelike. But we argue that visual rendering issues are pressing and need to be seriously addressed as well.

A layered framework for evaluating on-line collaborative learning interactions

Abstract: Evaluating on-line collaborative learning interactions is a complex task due to the variety of elements and factors that take place and intervene in the way a group of students comes together to collaborate in order to achieve a learning goal. The aim of this paper is to provide a better understanding of group interaction and determine how to best support the collaborative learning process. To that end, we propose a principled framework for the study and analysis of group interaction and group scaffolding which is built by combining different aspects and issues of collaboration, learning and evaluation. In particular, we define learning activity indicators at several levels of description which prompt to the application of a mixed interaction analysis scheme and the use of different data types and specific tools. At an initial layer, the basis of the approach is set by applying a qualitative process for evaluating the individual and group task performance as well as the group functioning and scaffolding. The interaction analysis process is completed by defining and applying two more layers: a social network analysis of the group activity and participation behaviour and a quantitative analysis of group effectiveness as regards task achievement and active interaction involvement. Our work defines a grounded and holistic conceptual model that describes on-line collaborative learning interactions sufficiently and applies it in a real, web-based, complex and long-term collaborative learning situation. An in-depth empirical evaluation of the conceptual model is fully discussed, which demonstrates the usefulness and value of the approach.

User perception of adapting video quality

Abstract: In general, video quality adaptation and video quality evaluation are distinct activities. Most adaptive delivery mechanisms for streaming multimedia content do not explicitly consider user-perceived quality when making adaptation decisions. Equally, video quality evaluation techniques are not designed to evaluate instantaneous quality where the quality is changing over time. We propose that an Optimal Adaptation Trajectory (OAT) through the set of possible encoding exists, and that it indicates how to adapt encoding quality in response to changes in network conditions in order to maximize user-perceived quality. The subjective and objective tests carried out to find such trajectories for a number of different MPEG-4 video clips are described. Experimental subjective testing results are presented that demonstrate the dynamic nature of user perception with adapting multimedia. The results demonstrate that adaptation using the OAT out-performs conventional adaptation strategies in which only a single aspect of the video quality is adapted. In contrast, the OAT provides a mechanism to adapt multiple aspects of the video quality thereby giving better user-perceived quality in both the short and long term.

Pair programming productivity: Novice-novice vs. expert-expert

Abstract: Agile Software Development methodologies have grown in popularity both among academic researchers and industrial practitioners. Among the various methodologies or practices proposed, pair programming, which is concerned with two programmers collaborating on design, coding and testing, has become a controversial focus of interest. Even though some success stories have been reported with the use of pair-programming in real software development environment, many people remain rather skeptical of the claims on pair-programming productivity. Previous studies in pair programming have only addressed the basic understanding of the productivity of pairs and they have not addressed the variation in productivity between pairs of varying skills and experience, such as between novice-novice and expert-expert. Statistical productivity measurements reported by different researchers also seem to lead to contradictory conclusions. Until now, the literature has not addressed how those results and experiments were related to each other. In this paper, we propose a controlled experiment called repeat-programming which can facilitate the understanding of relationships between human experience and programming productivity. Repeat-programming can be performed when controversial issues in non-traditional programming methodologies and development productivity need to be investigated into. To illustrate how the proposed empirical experiment can put arguable, divisive problems into perspective, we have examined the productivity in pair programming as a case study. With repeat-programming, we are able to (i) better understand why results of previous pair programming control experiments reached different conclusions as to the productivity of pair programming and (ii) most importantly, present a case in which novice-novice pairs against novice solos are much more productive than expert-expert pairs against expert solos.

Surviving task interruptions: Investigating the implications of long-term working memory theory

Abstract: Typically, we have several tasks at hand, some of which are in interrupted state while others are being carried out. Most of the time, such interruptions are not disruptive to task performance. Based on the theory of Long-Term Working Memory (LTWM; Ericsson, K.A., Kintsch, W., 1995. Long-term working memory. Psychological Review, 102, 211-245), we posit that unless there are enough mental skills and resources to encode task representations to retrieval structures in long-term memory, the resulting memory traces will not enable reinstating the information, which can lead to memory losses. However, once encoded to LTWM, they are virtually safeguarded. Implications of the theory were tested in a series of experiments in which the reading of an expository text was interrupted by a 30-s interactive task, after which the reading was continued. The results convey the remarkably robust nature of skilled memory-when LTWM encoding speed is fast enough for the task-processing imposed by the interface, interruptions have no effect on memory, regardless of their pacing, intensity, or difficulty. In the final experiment where presentation time in the main task was notably speeded up to match the limits of encoding speed, interruptions did hamper memory. Based on the results and the theory, we argue that auditory rehearsal or time-based retrieval cues were not utilized in surviving interruptions and that they are in general weaker strategies for surviving interruptions in complex cognitive tasks. We conclude the paper by suggesting three ways to support interruption tolerance by the means of task and interface design: (1) actively facilitating the development of memory skills, (2) matching encoding speed to task processing demands, and (3) supporting encoding-retrieval symmetry.

Cultural differences on attention and perceived usability: Investigating color combinations of animated graphics

Abstract: This experimental study investigates the effects of animated graphic colors on attention and perceived usability of users from two cultural groups, American and Thai. The experiment employs a three-way split-plot design with one between-subjects factor and two repeated-measures factors. The between-subjects factor contains two cultural groups, American and Thai. The two repeated-measures variables are a banner background color factor with six levels and a banner font color factor with two levels. Participants search for target words from text on Web pages that contain three animated banner graphics. The findings lead to the conclusion that users across cultures tend to ignore animated banner graphics when they look for specific information on highly informative Web pages. This study also suggests influences of culture on overall performance, overall retention, and overall self-reports on usability, regardless of differences in banner color combinations. Moreover, cultural differences on the self-report of attention drawing are also revealed in each banner color usage, except yellow banners with white text. This study does not aim at exploring superiority of participants between cultures. Rather, it attempts to explore some possible cultural differences in interacting with a computer interface that could facilitate cognition and perception of users from different cultural groups.

Assessing facial beauty through proportion analysis by image processing and supervised learning

Abstract: Perception of universal facial beauty has long been debated amongst psychologists and anthropologists In this paper, we perform experiments to evaluate the extent of universal beauty by surveying a number of diverse human referees to grade a collection of female facial images Results obtained show that there exists a strong central tendency in the human grades, thus exhibiting agreement on beauty assessment We then trained an automated classifier using the average human grades as the ground truth and used it to classify an independent test set of facial images The high accuracy achieved proves that this classifier can be used as a general, automated tool for objective classification of female facial beauty Potential applications exist in the entertainment industry, cosmetic industry, virtual media, and plastic surgery

A framework for asynchronous change awareness in collaborative documents and workspaces

Abstract: Change awareness is the ability of individuals to track the asynchronous changes made to a collaborative document or graphical workspace by other participants over time. We develop a framework that articulates what change awareness information is critical if people are to track and maintain change awareness. Information elements include: knowing who changed the artifact, what those changes involve, where changes occur, when changes were made, how things have changed and why people made the changes. The framework accounts for people's need to view these changes from different perspectives: an artifact-based view, a person-based view and a workspace-based view. Each information element is further broken down into distinguishing features and matched against these perspectives, e.g., location history within the where category prompts the questions 'where was this artifact when I left' in the artifact-based view, 'where in the workspace has a person visited' in the person-based view and 'where have people been in the workspace' in the workspace-based view. The framework can be used both to inform and critique change awareness tools.

The influence of font type and line length on visual search and information retrieval in web pages

Abstract: Most web sites are heavily text-based. Previous research has indicated that the way in which this text is presented may have a significant impact on usability. This paper reports findings from two experiments that explored the influence of font type and line length on a range of performance and subjective measures. Experiment 1 used a visual search task and Experiment 2 examined information retrieval. Overall, there was little impact of font on task performance, although the effect of line length was significant, with longer line lengths facilitating better scanning (Experiment 1) and shorter line lengths leading to better subjective outcomes (Experiments 1 and 2). Implications of these results for the design of web pages are discussed and recommendations given.

Computational modeling and experimental investigation of effects of compositional elements on interface and design aesthetics

Abstract: This article describes computational modeling and two corresponding experimental investigations of the effects of symmetry, balance and quantity of construction elements on interface aesthetic judgments. In the first experiment, 30 black and white geometric images were developed by systematically varying these three attributes in order to validate computational aesthetic quantification algorithms with subject ratings. The second experiment employed the same image layout as Experiment 1 but with realistic looking web pages as stimuli. The images were rated by 16 subjects in each experiment using the ratio-scale magnitude estimation method against a benchmark image with average balance and symmetry values and a standard number of elements. Subjects also established an ordered list of the images according to their aesthetic appeal using the Balanced-Incomplete-Block (BIB) ranking method. Results from both experiments show that subjects are adept at judging symmetry and balance in both the horizontal and vertical directions and thus the quantification of those attributes is justified. The first experiment establishes a relationship between a higher symmetry value and aesthetic appeal for the basic imagery showing that subjects preferred symmetric over non-symmetric images. The second experiment illustrates that increasing the number of groups in a web page causes a decrease in the aesthetic appeal rating.

A framework for designing sensor-based interactions to promote exploration and reflection in play

Abstract: Sensor-based interactions are increasingly being used in the design of user experiences, ranging from the activation of controls to the delivery of 'context-aware' information in the home. The benefits of doing so include the ability to deliver relevant information to people at appropriate times and to enable 'hands-free' control. A downside, however, is that sensor control often displaces user control, resulting in the user not knowing how to or being able to control aspects of a system. While this can be frustrating in many situations, it provides new opportunities for enhancing or augmenting various kinds of activities, where uncertainty can be exploited to good effect. We describe how we designed an adventure game for young children that incorporated a number of sensor-based interactions. We also present a preliminary conceptual framework intended to help designers and researchers develop novel user experiences using sensor-based interactions. A set of concepts are provided that characterize salient aspects of the user experience involved in sensing together with a discussion of the core properties of sensor technologies.

Toward a decision-theoretic framework for affect recognition and user assistance

Abstract: There is an increasing interest in developing intelligent human-computer interaction systems that can fulfill two functions-recognizing user affective states and providing the user with timely and appropriate assistance. In this paper, we present a general unified decision-theoretic framework based on influence diagrams for simultaneously modeling user affect recognition and assistance. Affective state recognition is achieved through active probabilistic inference from the available multi modality sensory data. User assistance is automatically accomplished through a decision-making process that balances the benefits of keeping the user in productive affective states and the costs of performing user assistance. We discuss three theoretical issues within the framework, namely, user affect recognition, active sensory action selection, and user assistance. Validation of the proposed framework via a simulation study demonstrates its capability in efficient user affect recognition as well as timely and appropriate user assistance. Besides the theoretical contributions, we build a non-invasive real-time prototype system to recognize different user affective states (stress and fatigue) from four-modality user measurements, namely physical appearance features, physiological measures, user performance, and behavioral data. The affect recognition component of the prototype system is subsequently validated through a real-world study involving human subjects.

Sensemaking tools for understanding research literatures: Design, implementation and user evaluation

Abstract: This paper describes the work undertaken in the Scholarly Ontologies Project. The aim of the project has been to develop a computational approach to support scholarly sensemaking, through interpretation and argumentation, enabling researchers to make claims: to describe and debate their view of a document's key contributions and relationships to the literature. The project has investigated the technicalities and practicalities of capturing conceptual relations, within and between conventional documents in terms of abstract ontological structures. In this way, we have developed a new kind of index to distributed digital library systems. This paper reports a case study undertaken to test the sensemaking tools developed by the Scholarly Ontologies project. The tools used were ClaiMapper, which allows the user to sketch argument maps of individual papers and their connections, ClaiMaker, a server on which such models can be stored and saved, which provides interpretative services to assist the querying of argument maps across multiple papers and ClaimFinder, a novice interface to the search services in ClaiMaker.

On theory-driven design and deployment of collaboration systems

Abstract: Early efforts to design and deploy collaboration systems were more art than science, but they produced some solid successes. Commercial groupware products now support millions of collaborations per year. Under certain circumstances teams that use group support systems perform far better than groups that do not. However, as impressive as the achievements are in this field, we can do better. A rigorous theoretical approach to the design of collaboration technology and process can lead us to non-intuitive design choices that produce successes beyond those possible with an intuitive, seat-of-the-pants approach. This paper explains the simple structure of a rigorous scientific theory and offers examples of theory-driven design choices that produced substantial benefits. It then differentiates rigorous theory from several classes of theory that have intuitive appeal, but cannot inform design choices. It concludes that the logic of the theory-driven design approach suggests that the most useful focus for collaboration technology researchers would be the technology-supported work-process, rather than just the technology.

Identifying usability and fun problems in a computer game during first use and after some practice

Abstract: This paper describes an experiment to discover the change in the types of detected problems and the attitude of children towards a game when user testing a computer game for young children during first use and after they have practiced with a game. Both the numbers of different types of identified problems and the severity of the problems are investigated. Based on this knowledge, practitioners could adapt the set up of their user tests to effectively find as many aspects of the game as possible that merit change, according to the aims of the developers. The study shows that usability problems caused by a lack of knowledge were more often identified during first use. Furthermore, fun problems related to a too-high challenge level may disappear after some practice, whereas fun problems caused by the game taking over control for too long while the user wants to proceed playing the game were identified more often after some practice. The study shows that the impact severity of problems detected during first use was higher than when children had more practice with a game. As a result of these changes in experienced problems the commonly used measures efficiency, effectiveness and satisfaction increased when children had practiced with the game. Finally, the study also shows that the set of most severe problems identified during first use may be radically different from the set of most severe problems identified after some practice.

Constructing computer-based tutors that are socially sensitive: Politeness in educational software

Abstract: Students rated 16 tutorial statements on negative politeness (i.e., how much the tutor ''allows me freedom to make my own decisions'') and positive politeness (i.e., how much the tutor was ''working with me''). Consistent with an adaptation of Brown and Levinson's [1987. Politeness: Some Universals in Language Use. Cambridge University Press, New York] politeness theory, (a) students rated direct commands and commands attributed to machines as lowest in negative and positive politeness, (b) students rated guarded suggestions and guarded questions as highest in negative politeness, and guarded suggestions and statements expressing a common goal as highest in positive politeness, and (c) the pattern of results was stronger for students with low rather than high computing experience. Results have implications for designing polite conversational agents in educational software.

Affective affordances: Improving interface character engagement through interaction

Abstract: The nature of humans interacting with interface characters (e.g. embodied agents) is not well understood. The I-PEFiC model provides an integrative perspective on human-character interaction, assuming that the processes of engagement and user interaction exchange information in explaining user responses with interface characters. An experiment using the Sims2 game was conducted to test the effects of aesthetics (beautiful versus ugly, as engagement factor) and affordances (help versus obstacle, as interaction factor) of interface characters on use intentions, user engagement, and user satisfaction. Results of the experiment showed that (1) people tended to use helpful characters more than obstructing characters, (2) user engagement was enhanced by beauty and perceived affordance of the character whereas (3) intentions to use the character were not affected by good looks, and (4) the most satisfied users were those that were engaged with the character as well as willing to use it. This stresses the importance of enhancing affordances so to increase user engagement with interface characters. The I-PEFiC model provided a valuable framework to study the (interdependent) effects of relevant factors in human-character interaction.