This is the first paper that estimates the price determinants of BitCoin in a Generalised Autoregressive Conditional Heteroscedasticity framework using high frequency data. Derived from a theoretical model, we estimate BitCoin transaction demand and speculative demand equations in a GARCH framework using hourly data for the period 2013-2018. In line with the theoretical model, our empirical results confirm that both the BitCoin transaction demand and speculative demand have a statistically significant impact on the BitCoin price formation. The BitCoin price responds negatively to the BitCoin velocity, whereas positive shocks to the BitCoin stock, interest rate and the size of the BitCoin economy exercise an upward pressure on the BitCoin price.
Classifiers are applied in many domains where classification errors have significant implications. However, end-users may not always understand the errors and their impact, as error visualizations are typically designed for experts and for improving classifiers. We discuss the specific needs of classifiers' end-users, and a simplified visualization designed to address them. We evaluate this design with users from three levels of expertise, and compare it with ROC curves and confusion matrices. We identify key difficulties with understanding the classification errors, and how visualizations addressed or aggravated them. The main issues concerned confusions of the actual and predicted classes (e.g., confusion of False Positives and False Negatives). The machine learning terminology, complexity of ROC curves, and symmetry of confusion matrices aggravated the confusions. The end-user-oriented visualization reduced the difficulties by using several visual features to clarify the actual and predicted classes, and more tangible metrics and representation. Our results contribute to supporting end-users' understanding of classification errors, and informed decisions when choosing or tuning classifiers.
Systems evolve with societal, business and technological changes. Because of these changes, socio-technical systems need to adapt to new situations that were unknown at the time of design. Good knowledge of system evolution can help with that adaption. Although the evolution of software and interactive systems has been broadly debated, little research has been conducted on the specific genre of systems and even less empirical research on the evolution of interactive software has been performed. We propose a three-dimensional framework which consists of what changes during the evolution of training simulators, what are the drivers for those changes and how the changes effect innovation and robustness of the training simulators. By reviewing the literature on training simulators, we argue for this framework. The contribution of the paper is a framework that can be used to carry out empirical studies on evolution of training simulators.
Permanent reachability via mobile communications technologies has become a ubiquitous phenomenon. The traditional boundaries between peoples’ different contexts in their lives become blurry and begin to dissolve, if they are not actively maintained. Such boundary management activities allow to individually determine which communication request are considered acceptable in a particular context. Existing research in this field has a used a fixed set of pre-specified contexts to examine boundary management activities and identify different boundary profiles. Based on results from context-aware computing and mental model research, we argue for an open-ended, individual set of contexts to be considered for boundary management. Consequently, we develop an open structure elaboration technique to allow for individual specification of contexts and the information necessary to create a boundary profile, as identified in related work. The method is validated in an exploratory study, which was designed to verify the hypothesis that boundary management should be based on individually specified contexts, and show the feasibility of the proposed method. The results indicatively confirm our assumptions and show that the method can be used to elicit the required information.
User experiences have been the focal research issue in service design (SD), as it has various benefits.As it will be demonstrated in this paper, developing an efficient, yet usable crisis management service requires a deep understanding of the experience (UX) of all stakeholders involved in the crisis.While many SD studies have proposed different principles, practices and tools, there is a lack of a practical comprehensive design framework that empowers designers to integrate effectively UX in the SD lifecycle.In this paper the authors propose a methodological framework called UXD-IS (User eXperience Design of Interactions and Services) that combines UX characterization and touchpoints analysis.The framework has been validated through a case study related to flooding crisis management.The investigations reveal that the framework is a powerful support tool during the first phases of the development of a new service or the improvement of an existing one.
Human-computer interaction (HCI) research has recently become more interested in studying practices. Looking beyond the novelty of technology, practice studies try to understand how technology becomes integrated into everyday life and how it shapes everyday practices in the longer time span. The contribution of this article is to demonstrate how ubiquitous computing practices develop. The article also sheds light on children’s and their families’ smart device practices in private and public settings. This paper responds to the recent call for practice studies in HCI and tries to understand technology-mediated practices of children and their families in their everyday lives. We first focused on children’s practices with a multipurpose public display through an ethnographic field study, and then broadened our focus to the children’s and families’ smart device practices through a diary study. We showed that children’s practices with a public display were surprisingly similar to their other information and communication technology (ICT) practices at home and elsewhere. In both settings, displays were used for entertainment and time-killing, as well as for babysitting and social interaction. This study indicates that technology-mediated practices do not spring up from the ground fully formed. There are several factors contributing to the practices’ emergence: the artefact itself and its affordances, the nature of the space, and the mind-set of the users. This finding has many implications for research and design, indicating that when developing technology, we should pay attention to a variety of factors that might be contributing to the emergence of practice around that technology – factors not yet fully explored by current research.
One approach to getting to know a user and understanding the user experience (UX) is phenomenology. Currently, there is a lack of clearly defined methods for phenomenological analysis of user experience in design projects. Interpretative Phenomenological Analysis (IPA) is an approach developed in psychology, and in this article, it is adapted to the case of a pro bono design project at a UX design agency supporting a disadvantaged group of people, newly arrived immigrants to Sweden. The design project involved research on how the immigrants experienced a service that introduced them to the job market. The adapted method, UX IPA, contributed to the pro bono project with a focus on both experience and meaning, which is important in design projects that relate to major events in users’ lives. The method was considered less appropriate in UX projects for specific products with highly instrumental use. The method can, in many cases, be too costly. However, costs can possibly be reduced by top-down approaches. In commercial UX projects, the method may be appropriate for the fuzzy front-end of design and innovation, but clients may be unimpressed by the small sample size. This can potentially be alleviated by mixed-methods approaches.
Design artefacts are vital to communicate design outcomes, both in remote and co-located settings. However, it is unclear how artefacts are used to mediate interactions between designers and stakeholders of the design process. The purpose of this paper is exploring how professional design teams use artefacts to guide and capture discussions involving multidisciplinary stakeholders while they work in a co-located setting. An earlier draft of this paper was paper published in the Proceedings of the European Conference on Cognitive Ergonomics (ECCE 2017). This work adds substantial clarification of the methodology followed, further details and photographs of the case studies, and an extended discussion about our findings and their relevance for designing interactive systems. We report the observations of six design meetings in three different projects, involving professional design teams that follow a user-centered design approach. Meetings with stakeholders are instrumental for design projects. However, design teams face the challenge of synthesizing large amounts of information, often in a limited time, and with minimal common ground between meeting attendees. We found that all the observed design meetings had a similar structure consisting of a series of particular phases, in which design activities were organized around artefacts. These artefacts were used as input to disseminate and gather feedback of previous design outcomes, or as output to collect and process a variety of perspectives. We discuss the challenges faced by design teams during design meetings, and propose three design directions for interactive systems to coordinate design meetings revolving around artefacts.
HCI, whether for research or for specific usability case studies, tries to align the user task with the user interface design, with its computer implementation.For research, HCI tries to identify the principles; for specific case studies, HCI tries to improve the user experience or the product delivered.In all approaches, the user task is central, yet the user task may be an artifact of previous implementations (it may suffer implementation bias), and users -and user studies -may therefore accidentally focus on problems with their current task as implemented rather than opportunities for a new HCI approach.In this paper, we use presentations (i.e., giving talks or lectures) as a detailed stand-alone case study, and we show that implementation bias is a serious impediment to thinking clearly about improving the task of delivering quality presentations.We then argue, using a very different example (healthcare IT) that implementation bias is, in fact, a common and serious problem across HCI generally.
Pirates famously say "AARRR."In a Pirate Talk, AARRR is a mnemonic for A udience, A ction, R emember, R oute
The present study aimed to investigate the ability of psychotherapists to decipher emotional discourse in computer-mediated communication and whether delivery mediums can increase the ambiguity in their assessment.Ignoring any reduction in efficacy of remote therapy, it is assumed that therapists' experiences of communication and their ability to construct a diagnosis on the basis of what they perceive will be influenced by Computer-Mediated Psychotherapy.Participants of the study scaled four emotional factors i.e., intensity, valence, potency and activation to measure the constructive nature of emotional discourse.Among other findings, the study showed that estimating emotional factors of communication did not differ significantly across main delivery modalities (i.e., text, audio and video).The results demonstrate further that telecommunication technologies did not alter the diagnostic level of psychotherapists.However, the reduction of emotional perception is very much remarkable for clinicians' decisions when discourse is communicated via non-human computer-mediated mode.
The internet is an ever-expanding medium of communication; capable of connecting users with masses of information and countless services.In such a popular and competitive market, it is imperative that websites are both practical and pleasant to navigate.Using an eye-tracker, we obtained objective measurements of complexity with subjective ratings of complexity and aesthetics, to explore judgments arising from the perception of university homepages.As expected, high levels of perceived complexity resulted in low aesthetic ratings.Interestingly, fixation count correlated negatively with complexity and positively with aesthetics; a novel finding.We argue that high complexity and negative aesthetic appraisals are a result of cognitive overload due to the limited capacity of working memory.We suggest ways in which web designers can avoid information overload, by complying with the known limits of human cognition, to maximize the positive interaction between webpage and user.
Effective communication is a key factor for the success of teams.More recently, globalization and modern communication technologies have contributed to the prevalence of multicultural teams and fast communication paths, creating additional challenges for effective communication.To support multicultural communication, a web-based communication model for multicultural teams (comMCT) was previously developed.To the best of the authors' knowledge, this is the only communication model for MCTs that provides a web-based representation and includes modules addressing a wide spectrum of interpersonal, structural, functional, and organizational aspects of effective multicultural team communication.The objective of the current effort is to evaluate and enhance the model with the participation of subject matter expert end-users.In the study, an international sample of 15 project managers evaluated the comMCT model on 7 criteria: completeness, structure, language, redundancy, understandability, originality, and usefulness.On a scale of YES!; Rather yes; Partly yes, partly no; Rather no, and NO!, the model was rated as good (corresponding to answer option 'Rather yes') or very good (corresponding to 'YES!') on all criteria except for redundancy.In addition, participants' free text comments provided suggestions for improving the model in terms of complexity, interactivity, and calibration.Overall, the comMCT model was considered helpful and useful for supporting intercultural, work-related communication.Yet, further research and incremental optimization are needed in this domain.
In this research, an extension of a dyadic (pair) team cognition model is proposed to describe the cognition of a team with more than two persons. This model provides a comprehensive framework for analysing the cognitive aspects of team interactions, such as team situation awareness, team memory, and human-agent interactions. One important aspect discussed in this research is a process called mental subgrouping. In a team with more than two persons, for each member to think of the other members as a single entity instead of several different individuals is natural. This behaviour is defined as mental subgrouping. By incorporating mental subgrouping into the mutual belief model, this research attempts to more accurately describe the cognition of a team from the perspective of both an outsider and the individual team members.
Interaction Science has undergone rapid development since JoIS’ (the Journal of Interaction Science) founding in 2013. The advent of novel techniques and tools required reviewing the understanding of Interaction Science and the scope and aims of JoIS. More particularly, the set of methods and frameworks needed to be revisited and checked against the characteristics of today’s ecological system and the resulting requirements for developing socio-technical systems. In this editorial, we tackle the interdisciplinary nature of Human-Computer-Interaction, the different thematic areas in Interaction Science, and diverse scientific research methods (and methodologies). We also examine the JoIS articles published so far, in order to provide a sound baseline for re-defining Interaction Science and update the mission of JoIS accordingly. The newly proposed definition of Interaction Science explicitly takes into account diversity and transdisciplinarity of interactional phenomena. We recognize the action space of Interaction Science being complex and ever-changing, and thus opt for wide generalization. Such way, the interaction is considered as the exchange of material or immaterial goods between acting parties (biological or technical entities) embodied in a certain context. Regarding scientific methodology, one of the important proposals relevant to JoIS is to relax emphasize on the use of empirical investigation based on traditional laboratory experiment. Traditional laboratory empiricism (usually empowered by statistics and hypothesis testing) is too restrictive to exclusively represent JoIS’ aims and scope, so we make way to complementary methods such as modeling, simulation, case studies, and design as science. By acknowledging studies of new methodologies, metrics and measurements, as well as work grounded in theories and applications, we ask for future contributors to stay committed to the TEAM (Theory advancement, Empirical advancement, Applied advancement, Methodological advancements) approach. We finally anticipate for the next decade Interaction Science will progressively integrate its scientific concerns with the engineering goal of improving the interactive design of socio-technical systems, resulting in a body of transdisciplinary knowledge and methodology. Interaction Science continues to provide a challenging test domain for applying and developing psychological and social theory in the context of technology development and use.
This pilot study aims to find a way to measure ‘presence’ as a proxy for ecological validity in driving simulators. The underlying assumption is that a person experiencing a strong sense of presence in the virtual environment will react as if it were real. We measure ‘presence’ through the ‘attention’ given to the driving task. We hypothesize that the greater the attention given to the primary driving task, the more the subject will experience spatial presence. ‘Attention’ was varied by adding a second task and oncoming traffic; we then analyzed behavioral measures of driving performance and subjective ‘presence’. The main result is a lack of congruence between subjective and behavioral measures. Although behavioral differences were observed between the various experimental conditions, there was no significant difference in subjective measures of presence. One explanation for this result could be that in all experimental conditions the driving activity did not require high-level cognitive processes, and was instead based on bottom-up attentional processes. Many of the processes involved in driving seem to be automatic, and this study argues for the concomitant use of subjective measures (such as questionnaires) and objective measures to assess presence in driving simulators. Furthermore, the development of a sensitive measure of presence seems to require more challenging scenarios in terms of controlled attention, cognitive involvement and more specifically, the emotions induced by the media. Participants are clearly aware that they are not exposed to any physical danger when using the simulator and the problem of their motivation must be taken into consideration. Another major problem is to establish the extent to which they are absorbed in the simulated driving task. A significant challenge for future research is the emotional validity of driving.
Cognitive Engineering puts models of mental processes and cognitive systems into interaction practice, and at the same time seeks to explain phenomena, predict behavior, and develop schemes to process representations of cognitive models. This is complicated by social, emotional, and technical factors that are present in interactive settings. Consequently, researchers and practitioners in the area of cognitive engineering face the challenge to address these factors as well as the influence and context of technological artifacts themselves. This endeavor requires structured discourse on methodological and technical knowledge and findings across disciplines (cf. [1]). As technology and technological artifacts have become abundant in everyday life, the design and evaluation of socio-technical aspects like situation-awareness, cognitive task analysis, work design, and the identification of common cognitive reference points are of crucial importance. Hence the role of stakeholders (designers, project managers, workers etc.) requires review, in particular, with respect to their informed involvement in development processes (cf. [2]). Their capabilities, including selforganized adaptation of artifacts and learning, are increasingly becoming essential for achieving certain qualities (cf. [3]), such as resilience of systems in diverse contexts of use. Cognitive engineering can be seen as an academic and practical endeavor. Proponents of both areas operate out of different backgrounds, ‘differences in defining and tackling problems—that prevail in the systems of science and practice’ ([4], p. 517). These differences come into play when taking into account that ‘communication elements of one system, such as science, cannot be authentically integrated into communication of other systems, such as the system of a business organization’ (ibid., p. 516). For well-reasoned engineering processes adjusted knowledge from science and practice is required, in particular aligned assumptions and mindsets behind specific development approaches (cf. [5, 6]). This adjustment is of particular importance when artifacts are created in collaborative settings (cf. [7]). There are many ways to start and guide this process of development. In this issue, the inquiry of engineering knowledge in the course of system development is investigated. It allows practitioners to frame their acquisition of development knowledge and the identification of system requirements (cf. [5, 8]). Such an approach does not exclude generative developments, such as the on-site collaboration of research and development practice (cf. [9, 10]). The findings presented in this special issue on recent advances in cognitive engineering show the continuous need for analyzing concrete designs and implementations of cognitive models and their construction processes. Experiencing cross-disciplinary discourse in this way allows setting the stage for comprehensively informed and systemically analyzed research and development efforts. Discipline-specific approaches to cognitive engineering are challenged as they are likely to leave open essential questions of socio-technical system design. Instead, ways of working with cognitive systems and models in a sociotechnical context are identified fostering research and theory building. The authors address several tensions associated with integrating various elements, including development assumptions, design dimensions, communication styles, rigor and relevance, and stakeholder interests, and show how such tensions are valuable themselves for research and theorizing (cf. [2, 11, 12]). The contributions reveal conflicting objectives, and practitioners’ dilemmas. They describe the dialectical forces that foster the tensions associated with gaps, including studying specific phenomena, stakeholder involvement, and dedicated user support systems, namely for navigation and social relationships handling. In some cases the tensions represent fundamental, unresolvable paradoxes that can be generative of new research and practice if appreciated as such. The contributions take different approaches on phenomena occurring in actual situations of using technical Correspondence: christian.stary@jku.at Department of Business Information Systems Communications Engineering, JKU Knowledge Management Competence Center, Johannes Kepler Universitat Linz, Science Park III, Altenbergerstrase 69, 4040 Linz, Austria
The role of affect and emotion in interactive system design is an active and recent research area. The aim is to make systems more responsive to user's needs and expectations. The first step towards affective interaction is to recognize user's emotional state. Literature contains many works on emotion recognition. In those works, facial muscle movement, gestures, postures and physiological signals were used for recognition. The methods are computation intensive and require extra hardware (e.g., sensors and wires). In this work, we propose a simpler model to predict the affective state of a touch screen user. The prediction is done based on the user's touch input, namely the finger strokes. We defined seven features based on the strokes. A linear combination of these features is proposed as the predictor, which can predict a user's affective state into one of the three states: positive (happy, excited and elated), negative (sad, anger, fear, disgust) and neutral (calm, relaxed and contented). The model alleviates the need for extra setup as well as extensive computation, making it suitable for implementation on mobile devices with limited resources. The model is developed and validated with empirical data involving 57 participants performing 7 touch input tasks. The validation study demonstrates a high prediction accuracy of 90.47 %. The proposed model and its empirical development and validation are described in this paper.
Navigation within a website is an important factor for the success of a website. Faster and easy web-navigation leads to better usability and reduces cognitive load on the user. Several cognitive models exist that simulate the web-navigation process. In this paper we propose a new cognitive model – CoLiDeS++Pic (based on Comprehension-based Linked model of Deliberate Search or CoLiDeS) that incorporates path adequacy and backtracking strategies. This model also takes into consideration the semantics of pictures. Firstly, we present here the results of an experiment in which we test the efficacy of support based on the new model CoLiDeS++Pic and multi-tasking under cognitively demanding situations. The results prove that the model-generated support is effective. Secondly, we also propose that in this way navigation behavior can be better modeled when compared to previous models. We verify this hypothesis by simulating the model on a mock-up website and comparing the results with a previous model CoLiDeS+. Extending our previous work we demonstrate that the performance of the new model CoLiDeS++Pic is improved compared to the preceding model CoLiDeS+. We further discuss the challenges and advantages of automating navigation support using the proposed model.
The use of calendars for work and personal activities has been widely investigated for decades and the term calendar work, coined by Palen (CHI 17-24,1999), refers to the many ways people employ and interact with calendars. Previous research has focused on calendar usage in specific domains or on the differences between paper and digital calendars. The current paper is positioned somewhat differently by exploring calendars as object in personal ecologies of calendar artifacts. In such personal calendar ecologies, the users, their tasks, their practices, and the calendar artifacts adapt and evolve together. In addition, individual users are typically engaged in various activities in specific contexts (realms) that are established and maintained by groups of people, supporting the overarching culture of these realms. As such, the web of common practices, activities and tasks, as well as the calendar artifacts shape the individual calendar work. To our knowledge, this article is the first study that investigates diverse personal ecologies of calendar artifacts. To this end we collected detailed user data with (a) exploratory interviews and (b) the Day-Reconstruction Method. The results indicate that the changing demands in daily life, the availability of new tools, and the participants’ knowledge about the costs and benefits of their calendar work and about the consequences of potential failures influence their tendency to explore and possibly integrate new calendar artifacts and appear implicated in the deliberate non-use of new technology. It appears that paper and digital calendar artifacts continue to co-exist. The results indicate an existing ‘appointment culture’ with a high demand of precisely scheduled episodes, and the importance of calendar artifacts for maintaining work and personal relationships in the light of the travel and new technologies for communication.
