Javier A. Bargas-Avila

Bio: Javier A. Bargas-Avila is an academic researcher from University of Basel. The author has contributed to research in topics: Usability & User experience design. The author has an hindex of 20, co-authored 35 publications receiving 2125 citations. Previous affiliations of Javier A. Bargas-Avila include Google.

Old wine in new bottles or novel challenges: a critical analysis of empirical studies of user experience

Abstract: This paper reviews how empirical research on User Experience (UX) is conducted. It integrates products, dimensions of experience, and methodologies across a systematically selected sample of 51 publications from 2005-2009, reporting a total of 66 empirical studies. Results show a shift in the products and use contexts that are studied, from work towards leisure, from controlled tasks towards open use situations, and from desktop computing towards consumer products and art. Context of use and anticipated use, often named key factors of UX, are rarely researched. Emotions, enjoyment and aesthetics are the most frequently assessed dimensions. The methodologies used are mostly qualitative, and known from traditional usability studies, though constructive methods with unclear validity are being developed and used. Many studies use self-developed questionnaires without providing items or statistical validations. We discuss underexplored research questions and potential improvements of UX research.

Is beautiful really usable? Toward understanding the relation between usability, aesthetics, and affect in HCI

Abstract: This paper analyzes the relation between usability and aesthetics. In a laboratory study, 80 participants used one of four different versions of the same online shop, differing in interface-aesthetics (low vs. high) and interface-usability (low vs. high). Participants had to find specific items and rate the shop before and after usage on perceived aesthetics and perceived usability, which were assessed using four validated instruments. Results show that aesthetics does not affect perceived usability. In contrast, usability has an effect on post-use perceived aesthetics. Our findings show that the ''what is beautiful is usable'' notion, which assumes that aesthetics enhances the perception of usability can be reversed under certain conditions (here: strong usability manipulation combined with a medium to large aesthetics manipulation). Furthermore, our results indicate that the user's affective experience with the usability of the shop might serve as a mediator variable within the aesthetics-usability relation: The frustration of poor usability lowers ratings on perceived aesthetics. The significance of the results is discussed in context of the existing research on the relation between aesthetics and usability.

Visual complexity of websites: Effects on users' experience, physiology, performance, and memory

Abstract: Visual complexity is an apparent feature in website design yet its effects on cognitive and emotional processing are not well understood. The current study examined website complexity within the framework of aesthetic theory and psychophysiological research on cognition and emotion. We hypothesized that increasing the complexity of websites would have a detrimental cognitive and emotional impact on users. In a passive viewing task (PVT) 36 website screenshots differing in their degree of complexity (operationalized by JPEG file size; correlation with complexity ratings in a preliminary study r=.80) were presented to 48 participants in randomized order. Additionally, a standardized visual search task (VST) assessing reaction times, and a one-week-delayed recognition task on these websites were conducted and participants rated all websites for arousal and valence. Psychophysiological responses were assessed during the PVT and VST. Visual complexity was related to increased experienced arousal, more negative valence appraisal, decreased heart rate, and increased facial muscle tension (musculus corrugator). Visual complexity resulted in increased reaction times in the VST and decreased recognition rates. Reaction times in the VST were related to increases in heart rate and electrodermal activity. These findings demonstrate that visual complexity of websites has multiple effects on human cognition and emotion, including experienced pleasure and arousal, facial expression, autonomic nervous system activation, task performance, and memory. It should thus be considered an important factor in website design.

The role of visual complexity and prototypicality regarding first impression of websites: Working towards understanding aesthetic judgments

Abstract: This paper experimentally investigates the role of visual complexity (VC) and prototypicality (PT) as design factors of websites, shaping users' first impressions by means of two studies. In the first study, 119 screenshots of real websites varying in VC (low vs. medium vs. high) and PT (low vs. high) were rated on perceived aesthetics. Screenshot presentation time was varied as a between-subject factor (50ms vs. 500ms vs. 1000ms). Results reveal that VC and PT affect participants' aesthetics ratings within the first 50ms of exposure. In the second study presentation times were shortened to 17, 33 and 50ms. Results suggest that VC and PT affect aesthetic perception even within 17ms, though the effect of PT is less pronounced than the one of VC. With increasing presentation time the effect of PT becomes as influential as the VC effect. This supports the reasoning of the information-processing stage model of aesthetic processing (Leder et al., 2004), where VC is processed at an earlier stage than PT. Overall, websites with low VC and high PT were perceived as highly appealing.

Symmetry and aesthetics in website design: It's a man's business

Abstract: In recent years the aesthetic appearance of user-interfaces has become a topic of increasing interest in the field of human-computer interaction (HCI). At the same time, it is well known that there are gender-specific effects in HCI. The present study investigates the effect of web page symmetry by taking gender differences into account. A total of 60 people (30 male, 30 female) participated in a laboratory experiment, where 20 website startpages had to be rated regarding symmetry, intuitive beauty, classical and expressive aesthetics. Results show that vertical symmetry is an important factor in aesthetic website design. It has an impact on intuitive straightforward beauty appraisals and on classical and expressive aesthetics judgments. Asymmetrically designed web pages were considered to be less beautiful and achieved lower scores on the classical and expressive dimensions. Moreover, the study indicates that the symmetry effect only occurs among male participants: only men react unfavorably to asymmetrically designed websites, whereas women's judgments are not influenced by symmetry. These findings should be taken into consideration by website designers, especially when they aim to design for target audience consisting of a majority of a certain gender.

Remembering. A Study in Experimental and Social Psychology, Cambridge (University Press) 1964.

Abstract: Part I. Experimental Studies: 2. Experiment in psychology 3. Experiments on perceiving III Experiments on imaging 4-8. Experiments on remembering: (a) The method of description (b) The method of repeated reproduction (c) The method of picture writing (d) The method of serial reproduction (e) The method of serial reproduction picture material 9. Perceiving, recognizing, remembering 10. A theory of remembering 11. Images and their functions 12. Meaning Part II. Remembering as a Study in Social Psychology: 13. Social psychology 14. Social psychology and the matter of recall 15. Social psychology and the manner of recall 16. Conventionalism 17. The notion of a collective unconscious 18. The basis of social recall 19. A summary and some conclusions.

Executive functions and self-regulation

Abstract: Self-regulation is a core aspect of adaptive human behavior that has been studied, largely in parallel, through the lenses of social and personality psychology as well as cognitive psychology. Here, we argue for more communication between these disciplines and highlight recent research that speaks to their connection. We outline how basic facets of executive functioning (working memory operations, behavioral inhibition, and task-switching) may subserve successful self-regulation. We also argue that temporary reductions in executive functions underlie many of the situational risk factors identified in the social psychological research on self-regulation and review recent evidence that the training of executive functions holds significant potential for improving poor self-regulation in problem populations.

The impact of online reviews on hotel booking intentions and perception of trust.

Abstract: A growing reliance on the Internet as an information source when making choices about tourism products raises the need for more research into electronic word of mouth. Within a hotel context, this study explores the role of four key factors that influence perceptions of trust and consumer choice. An experimental design is used to investigate four independent variables: the target of the review (core or interpersonal); overall valence of a set of reviews (positive or negative); framing of reviews (what comes first: negative or positive information); and whether or not a consumer generated numerical rating is provided together with the written text. Consumers seem to be more influenced by early negative information, especially when the overall set of reviews is negative. However, positively framed information together with numerical rating details increases both booking intentions and consumer trust. The results suggest that consumers tend to rely on easy-to-process information, when evaluating a hotel based upon reviews. Higher levels of trust are also evident when a positively framed set of reviews focused on interpersonal service.

Smart Homes that Monitor Breathing and Heart Rate

Abstract: The evolution of ubiquitous sensing technologies has led to intelligent environments that can monitor and react to our daily activities, such as adapting our heating and cooling systems, responding to our gestures, and monitoring our elderly. In this paper, we ask whether it is possible for smart environments to monitor our vital signs remotely, without instrumenting our bodies. We introduce Vital-Radio, a wireless sensing technology that monitors breathing and heart rate without body contact. Vital-Radio exploits the fact that wireless signals are affected by motion in the environment, including chest movements due to inhaling and exhaling and skin vibrations due to heartbeats. We describe the operation of Vital-Radio and demonstrate through a user study that it can track users' breathing and heart rates with a median accuracy of 99%, even when users are 8~meters away from the device, or in a different room. Furthermore, it can monitor the vital signs of multiple people simultaneously. We envision that Vital-Radio can enable smart homes that monitor people's vital signs without body instrumentation, and actively contribute to their inhabitants' well-being.