Social recommender systems on entertainment platforms help users discover content through compatible social relationships. As transparency increases, users can better identify well-suited friends and make informed decisions about what content to watch. This study aims to investigate the effects of social profiles and explanation levels on enhancing user experience in a recommender system. We conducted a 3 (social profile types) × 3 (explanation levels) between-subject experiment, measuring decision-making efficiency, effectiveness, information richness, transparency, recommendation quality, user satisfaction, persuasiveness, and social presence. Results showed that profiles presenting both positive and negative preferences significantly improved subjective evaluations over profiles with only negative preferences. Moreover, our findings indicated that explanation levels should be tailored to social profiles to reduce decision-making effort and enhance user experience, including recommendation quality and satisfaction. These findings offer theoretical and practical contributions for designing user-centered social recommender systems that effectively support social matching and content discovery.

People use diverse read-it-later tools to save webpages for future uses; however, difficulties in scrap retrieval remain. Our study aims to understand users’ mental models of read-it-later tools and suggests a new tool, Read-It-Now, for web scraping. We conducted interviews to identify web scraping habits and developed four main design recommendations for read-it-later tools: tool hierarchy, contextual aids, proactive triggers, and multiple navigation strategies. With a focus on the proactive trigger that facilitates scrap retrieval, Read-It-Now is designed to recommend relevant web scraps based on a comparison of the title of the current browser tab. We tested the design prototype against traditional bookmarks and found that users preferred Read-It-Now because of its simplicity and effectiveness; however, explanations for scrap recommendations could be improved.

Majority opinions are often observed in online environments. Previous studies have demonstrated that majority opinions are constructed because people with minority opinions have fear of isolation, which forces them to be silent. However, we often observe that online users with different minority opinions fight each other, even though there are only a few. To explain this phenomenon, we developed a new theoretical model and examined it through the analysis of Reddit data. The results show that users in small communities expressed relatively homogeneous and less negative opinions, and constructed majority opinions that were not as strong as those in large communities. Contrarily, users in large communities showed relatively heterogeneous and more negative opinions, and built majority opinions more strongly than those in small communities. This implies that the model can properly explain why and how majority-opinion users are silent and why minority-opinion users are loud.

Users often encounter tedious recommendations as they are continuously exposed to the recommendation system. In response to this issue, serendipity in a recommendation system has been introduced to generate novel and unexpected recommendations while keeping them relevant to users’ previous preferences. This study proposes an interactive feedback loop for a serendipity in a recommendation system that allows users to directly explore content via counterfactual manipulation of features. Specifically, users indicate their preferences through the “what-if” based customization of content meta-information, and these modifications influence their usage history, thereby enabling the elicitation of serendipitous items. To validate the proposed feedback loop, we conducted a scenario-based experiment and compared system-initiated and user-intervened recommendations. The results reveal that counterfactual exploration can help to generate serendipitous recommendations. This study contributes to providing a user-friendly recommendation system that can retrieve preference-reflected recommendations through user interaction.

The limitations of accuracy-focused recommendation systems in improving user experiences have become apparent since user preferences change over time. Despite efforts to solve this issue through the examination of social information (e.g., relational data pertaining to users), capturing temporal user preferences remains a challenge. This study proposes a novel interaction method for integrating temporal user preferences into a social recommendation system. Users can highlight their preferred users within their social interactions. Through this interaction, preferences-integrated social information is incorporated into recommendations. We conducted a user test to validate the value of our proposed interaction method and found that the proposed approach had a positive impact on users’ subjective responses. The implications showed practical and theoretical improvements in user-centered recommendations.

Although the high performance of the convolutional neural networks (CNNs) for brain-computer interface (BCI) tasks based on raw electroencephalography (EEG) signals, the explanation of the prediction result remains challenging owing to their complex structure and numerous parameters. We propose a novel framework for explaining CNNs for EEG-based BCI tasks by using the perturbation-based influence scores. The method supports the interpretation of CNN classification for EEG signals at both the example-level and the feature-level. The experiments on the BCIC III-IVa dataset demonstrate that the proposed method is effective for not only the interpretation of the predictive models, but also for the improvement of the classification accuracy.

Contrary to the traditional concept of artificial intelligence, explainable artificial intelligence (XAI) aims to provide explanations for the prediction results and make users perceive the system as being reliable. However, despite its importance, only a few studies have investigated how the explanations of an XAI system should be designed. This study investigates how people attribute the perceived ability of XAI systems based on perceived attributional qualities and how the power status of the XAI and anthropomorphism affect the attribution process. In a laboratory experiment, participants (N = 500) read a scenarios of using an XAI system with either lower or higher power status and reported their perceptions of the system. Results indicated that an XAI system with a higher power status caused users to perceive the outputs of the XAI system to be more controllable by intention, and higher perceived stability and uncontrollability resulted in greater confidence in the system’s ability. The effect of perceived controllability on perceived ability was moderated by the extent to which participants anthropomorphised the system. Several design implications for XAI systems are suggested based on our findings.

In perceiving a virtual environment (VE), distance perception is important in that it affects users’ behaviors and interactions. This study addresses an on-going issue of virtual reality (VR), distance underestimation within a VE. For this purpose, a 2x2x2x5 mixed design was used with two between-subject variables [visual cue for perception (provided and non-provided) and visual cue for action (provided and non-provided)] and two within-subject variables [response measure (verbal estimation and triangulated blind walking) and distance (1 m, 5 m, 10 m, 20 m, and 35 m)]. Sixty-four undergraduate or graduate students participated in the experiment, and a cube was chosen as the target object. The experimental results showed that visual cues for action mitigated distance underestimation and improved the accuracy of perceived distances. In general, distance underestimation was more obvious in the triangulated blind walking than the verbal estimation, and in the action/vista space than personal space, with relatively lower accuracies. Meanwhile, when visual cue for action were provided, the degree of underestimation decreased significantly with higher accuracy particularly in the triangulated blind walking. Although overestimation was found across all the distances in the verbal estimation, overestimation was found only for the personal distance, and underestimation was found for the action/vista distances in the triangulated blind walking. In both response measures, the accuracy of distance perceptions were the worst in the 10 m condition. These findings can be expected to provide insight into the problem of distance underestimation and can help guide design of VEs.

For user experience studies, the affordance theory has been used to describe a user’s intuitive perception and action. This theory, however, has often faced problems in application due to the different viewpoints of the ecological psychology and other fields of application study. To address this issue, we adopt two strategies in this study. First, we review the existing explications of the affordance theory in ecological psychology and rectify issues that have hindered the use of concepts in the affordance theory for user experience analysis. In addressing these issues, we suggest revised formal expressions and propose a new typological system. Second, by organizing the revised formal expressions and the new typology of the affordance into a heterophenomenological frame, we suggest a research framework for user experience analysis. We present an application example of the framework for demonstration purposes. We expect that the suggested framework will enable better descriptions of various phenomena occurring in the physical, social, and self dimensions and designs of products and services.

A chatbot equipped with a conversational user interface often allows its users to feel as if they are conversing with a human being. The current study examined whether users’ perception of a mind within a chatbot is associated with their feeling of co-presence, closeness, and intention to use and whether the influence of mind perception is reinforced when the chatbot presents social cues in its language. A laboratory experiment (N = 64) revealed that the more participants perceived a mind behind a chatbot, the more co-presence and interpersonal closeness they experienced with the chatbot. The associations with co-presence and closeness became stronger when the chatbot used social cues. Furthermore, mind perception had an indirect effect on intention to use via closeness when social cues were presented. These findings imply the importance of mind perception and social cues in a chatbot’s language in creating a positive chatbot experience.

Sangwon Leea & Young June Saha* a Department of Interaction Science, Sungkyunkwan University, Seoul, South KoreaSangwon Lee is an associate professor in the department of Interaction Science, Sungkyunkwan University. He has obtained his PhD degree in Industrial Engineering at the Pennsylvania State University in 2010. His research interests include human-computer interaction, user experience, affective computing, and user modeling.Young June Sah (PhD, Michigan State University) is an adjunct professor in the department of Interaction Science, Sungkyunkwan University. His research interests include psychological and behavioral effects of media technologies and their cognitive mechanisms.CONTACT Young June Sah [email protected] Department of Interaction Science, Sungkyunkwan University, 25-2, Sungkyunkwan-ro, Jongno-gu, Seoul 110-745, South Korea.Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/hihc.ABSTRACTThe present study proposes an approach to measuring learnability, focusing on the learning process from a perspective of extended learnability. In developing a predictive model for time performance without any interruption or error based on NGOMSL (Natural GOMS Language), the concepts of “expertise time,” “actual time,” “learning deficit,” and “learning level” are considered with a few assumptions, and a learning deficit curve for the relationship between learning deficit and learning level is presented. Experimental data on repetitive use in sample users’ first use session of a system demonstrate the application of our approach herein. For exploratory tasks on four simulated websites with different levels of usability and aesthetics, responses from 64 users were obtained in terms of time performance, perceived usability, and user satisfaction. Through this application, we were able to discern some information about the dynamic properties of learning in relation to users’ subjective responses: (1) learning level according to number of uses, (2) the number of uses required to reach a competency level, (3) effects of usability and aesthetics factors on learning level, and (4) learning level in connection with perceived usability and user satisfaction. The model is expected to have potentials as an effective approach to measuring learnability insofar as it provides useful information in ways that differ from existing methods for learnability.

Jido is a conversational tactile map and a mobile application prototype to improve the orientation and mobility of visually impaired people. The tactile map can identify the user's touch gestures and their locations during tactile exploration to provide feedback. Users can verbally interact with a conversational agent through their mobile device to receive confirmation, request information of points of interest, and receive step-by-step instructions that can be later reviewed during navigation. In this work, we describe opportunities and challenges faced by tactile map users and present the findings on the preliminary evaluation of our prototype.

Users of voice user interface (VUI) often encounter errors, such as when a VUI attempts to recognize a user’s voice inputs or execute tasks. Conversation is prone to errors, and in the collaborative perspective, communicators manage common ground together to handle erroneous situations. Adopting a collaborative view of conversation, we propose that a VUI can address different types of errors by providing users with feedback to aid them in developing common ground to communicate more effectively. To test this proposal, we conducted a 2 (error type: recognition vs. execution error) × 2 (feedback elaboration: present vs. absent) mixed-design experiment in which users interacted with a VUI speaker and evaluated its usability in these four modes. Participants reported greater acceptance of feedback and higher usability perception for a speaker returning execution errors than for one returning recognition errors, particularly when the speaker presented feedback articulating reasons for the errors. This finding indicates that a VUI can employ feedback explaining the causes of errors to facilitate the development of common ground and to minimize the negative consequences of errors.

Since the introduction of smartphones in South Korea, users have shown quick and positive responses to them. This study explores issues in user satisfaction and develops strategies for user retention of a specific mobile telecommunications service provider in Korea. We presented a face-to-face questionnaire to 4398 participants representing nationwide characteristics of Korean users. Mobile telecommunications services and features were divided into two factors based on benefit segmentation and were analyzed with user profiling. Users’ responses to mobile telecommunications services were characterized as “Fundamental services and functions,” which meet users’ basic and traditional expectations for a smartphone as a communication and media tool, and “Cost and monetary benefits,” which mobile telecommunications providers offer to attract users. Based on the scores for those two factors, we divided respondents into five groups and addressed their characteristics in terms of demographic features, subscription duration, and factors that influence user satisfaction. The results of our analysis suggest strategies mobile communications providers can develop for each segment to promote high satisfaction and increase user retention. To improve satisfaction levels, relatively more efforts need to be invested in the fundamental services and functions.

In understanding user experience issues, it is necessary to consider contextual features in user interaction with an application. The present study aims to examine the differences among applications with difference contexts of use (perceived type: interaction styles based on use purposes) in terms of the relationships between user perception (perceived usability and perceived aesthetics) and emotion (valence and arousal). A study was performed using 15 existing websites from various domains. From the responses of participants, the relationships between perceived usability and emotional valence were found to differ according to perceived type, but those between perceived aesthetics and emotional valence were not. On the other hand, sufficient reliability for the arousal items was not secured. Through the meaningful categorization of arousal into two factors (negative and positive), significant differences in the relationships between perceived usability/aesthetics and emotional arousal could be found. Implications of the findings are discussed in the connection of contextual/design features, perceptual characteristics, and emotional responses in the development of interactive applications.

Although autonomous vehicles are increasingly becoming a reality, eliminating human intervention from driving may imply significant safety and trust-related concerns. To address this issue from a psychological perspective, this study applies layers of anthropomorphic cues to an artificial driving agent and explicates the process in which these cues promote positive evaluations and perceptions of an unmanned driving system. In a between-subjects factorial experiment (N = 89) consisting of three unmanned driving scenarios, participants interacted with an artificial driving agent with different levels of anthropomorphic cues induced by the variations in appearance (human-like vs. gadget-like) and autonomy (high vs. low) of the agent. The results indicated that human-like appearance and high autonomy were more effective in eliciting positive perceptions of the agent. In addition, a mediation analysis revealed that the greater level of anthropomorphism induced by human-like appearance and high autonomy in the agent evoked the feelings of social presence, which in turn positively affected the perceived intelligence and safety of and trust in the agent, suggesting that the extent to which users perceive the driving agent as intelligent, safe, and trustworthy is largely determined by the feelings of social presence experienced during their interaction.

This study proposes a new approach to developing a user behavior model to explain how a user finds the optimal use. This is achieved by considering user concerns, task significances, affordances, and emotional responses as the interaction components and by exploring behavior sequences for a goal in using a product the first time. The tasks in the same group at each level in the user concern structure are therefore in a competing relationship in going up to a higher task. The task tree with the significances and the affordance probabilities can be analyzed. The order of a user’s exploring behavior sequences can be determined through comparisons of the expected significances, which can be obtained by the modified subjective expected utility theory. A user’s emotional responses for the tasks that a behavior sequence is composed of can be calculated by the modified decision affect theory. Here, the emotional response refers to a user’s internal reactions for the degree to which a product’s affordance features can meet his or her mental model in use. The average emotional response for a behavior sequence can be a user’s decisional factor for the optimal use method in using a product with a goal. Also, the design problems of a product can be checked from users’ point of view, and the emotional losses/changes by usage failures can be discussed. For an illustrative purpose, the proposed model is applied to a numerical example with some assumptions.

In addressing user experience issues, users’ perceptions and emotions need to be considered important. This study examines the relationships between perceived usability/aesthetics and emotional valence/arousal/engagement through an experiment using 15 existing websites from various domains and questionnaire items developed to measure users’ responses. According to the experimental results, both perceived usability and perceived aesthetics were positively correlated with emotional valence and negatively correlated with emotional engagement. No specific relationship was found between perceived usability/aesthetics and emotional arousal. Perceived aesthetics potentially had a greater impact on valence than perceived usability. Unlike valence, engagement could be more influenced by perceived usability than by perceived aesthetics. These findings can be utilized as bases for applying users’ emotional responses in each dimension to the product-use situations in the chain of perceptions, emotions, and behaviors.

The concept of user experience emphasizes the importance of understanding users for applications that have various contextual features. To address this issue, this study examines the changes in the relationships among user satisfaction and users' perceptions of usability and aesthetics according to use situations. For data, an experiment was conducted using 15 existing websites with similar levels of usability and aesthetics. Forty-five engineering students participated in the experiment. The results indicated that the relationships among perceived usability, perceived aesthetics, and user satisfaction could be dependent on how users perceived the use purposes and interaction types of the websites. Specifically, the relationship between perceived usability and user satisfaction was stronger for websites requiring users' goal-directed activities, whereas the relationship between perceived aesthetics and user satisfaction was stronger for the websites mainly providing useful information, regardless of the existence of a specific use goal. Also, the strong relationship between perceived usability and perceived aesthetics was more obvious for websites where users mainly wanted to obtain information than for those where users primarily wanted to use the leisure and relaxation content. The findings can be utilized in the design of websites with different contextual features, especially related to use purposes and interaction types.

In developing an application, the importance of usability and user experience has become increasingly emphasized over the past few decades. An important factor in understanding these is the context in which the application is being used. To better understand the direct effect of context, two task characteristics (i.e., mental workload and operator control) were manipulated and their effects on perceived usability were examined through an experiment using simulated home security systems. The experimental results showed that both mental workload and operator control had significant effects on perceived usability. Also, the perceptions of mental workload and operator control were strongly correlated with perceived usability. The interaction between the mental workload and the operator control factors was not significant. Possible reasons for the results and practical implications for the findings are discussed.

Goals, Operators, Methods, and Selection rules (GOMS) is an analytic method and a model evaluation method for the knowledge necessary for a user to perform tasks in a system, and Natural GOMS Language (NGOMSL), a version of GOMS, is an attempt to define a language so that the GOMS model can be precisely constructed in a structured way. This study proposes Communicative NGOMSL, which is an extension of NGOMSL intended to accommodate modeling of text-based communication among two or more individuals. Besides the properties of GOMS techniques in evaluation, Communicative NGOMSL additionally considers common ground and communication time: Common ground refers to the mutual knowledge, beliefs, and assumptions of participants in communication, and communication time refers to the time that an individual waits for another to respond. The analysis of a Communicative NGOMSL model provides some information for a common task goal in a text-based communication system: (a) the relationship between the grounding process and Communicative NGOMSL statements, (b) the ratio of communication time to execution time for each individual, and (c) the balance among individuals in terms of learning time and mental workload. A demonstration of Communicative NGOMSL is provided through a sample case—a virtual text-based chat tool for exchanging addresses between two individuals. Future work needed to address the limitations of this study and further develop Communicative NGOMSL is discussed.

Understanding target users is a crucial issue in establishing design and marketing strategies for computer-based applications. To contribute to the comprehension of target users, this study examines the effect of cognitive style (imagers vs. verbalizers) on user preference based on perceived usability and perceived aesthetics through an experiment using four simulated systems with different levels of usability and aesthetics. Forty-two imagers and 31 verbalizers participated in the experiment. The results of the analyses of variance indicated that, before actual use, the effect of the aesthetics factor on user preference was significantly different between imagers and verbalizers but that of the usability factor was not. The difference between imagers and verbalizers with respect to the effect of the aesthetics/usability factor on time performance was not sufficiently demonstrated, nor was the difference between the two cognitive styles with regard to the effect of the aesthetics/usability factor on user preference after actual use. For the combined experimental data of users' responses before and after actual use, the interaction effect between cognitive styles and actual use on user preference was not significant. Some possible reasons for these results and the possibilities of an important role of cognitive style in users' preference making are discussed here. Further studies are necessary to better examine the impact of cognitive style.

Designing a highly preferred product or system is a crucial issue for better information-services and product sales. We attempted to understand the process of users' preference-making based on usability and aesthetics. In the present study, we examined the relationships among usability/aesthetics features, perceived usability/aesthetics, and user preference through an experiment using four simulated systems with different levels of usability and aesthetics. The results showed that, before actual use, user preference was significantly affected by the differences in aesthetics but marginally affected by the differences in usability. On the other hand, after actual use, user preference was significantly influenced by the differences in both usability and aesthetics. Regardless of the occurrence of actual use, user preference was highly correlated with both perceived usability and perceived aesthetics, which were strongly interrelated. Finally, actual use had a significant effect on perceived usability, perceived aesthetics, and user preference. The findings emphasize the importance of considering both perceived usability and perceived aesthetics. They also demonstrate the need for discriminating users' interactions before and after actual use, in developing a more preferable computer-based application. ?? 2010 Elsevier B.V. All rights reserved.

Tactile sensation is one of the most important sensory functions along with the auditory sensation for the visually impaired because it replaces the visual sensation of the persons with sight. In this paper, we present a tactile display device as a dynamic Braille display that is the unique tool for exchanging information among them. The proposed tactile cell of the Braille display is based on the dielectric elastomer and it has advantageous features over the existing ones with respect to intrinsic softness, ease of fabrication, cost effectiveness and miniaturization. We introduce a new idea for actuation and describe the actuating mechanism of the Braille pin in details capable of realizing the enhanced spatial density of the tactile cells. Finally, results of psychophysical experiments are given and its effectiveness is confirmed.