Usability issues and design principles for visual programming languages

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Despite two decades of empirical studies focusing on programmers and the problems with programming, usability of textual programming languages is still hard to achieve. Its younger relation, visual programming languages (VPLs) also share the same problem of poor usability. This research explores and investigates the usability issues relating to VPLs in order to suggest a set of design principles that emphasise usability. The approach adopted focuses on issues arising from the interaction and communication between the human (programmers), the computer (user interface), and the program. Being exploratory in nature, this PhD reviews the literature as a starting point for stimulating and developing research questions and hypotheses that experimental studies were conducted to investigate. However, the literature alone cannot provide a fully comprehensive list of possible usability problems in VPLs so that design principles can be confidently recommended. A commercial VPL was, therefore, holistically evaluated and a comprehensive list of usability problems was obtained from the research. Six empirical studies employing both quantitative and qualitative methodology were undertaken as dictated by the nature of the research. Five of these were controlled experiments and one was qualitative-naturalistic. The experiments studied the effect of a programming paradigm and of representation of program flow on novices' performances. The results indicated superiority of control-flow programs in relation to data-flow programs; a control-flow preference among novices; and in addition that directional representation does not affect performance while traversal direction does - due to cognitive demands imposed upon programmers. Results of the qualitative study included a list of 145 usability problems and these were further categorised into ten problem areas. These findings were integrated with other analytical work based upon the review of the literature in a structured fashion to form a checklist and a set of design principles for VPLs that are empirically grounded and evaluated against existing research in the literature. Furthermore, an extended framework for Cognitive Dimensions of Notations is also discussed and proposed as an evaluation method for diagrammatic VPLs on the basis of the qualitative study. The above consists of the major findings and deliverables of this research. Nevertheless, there are several other findings identified on the basis of the substantial amount of data obtained in the series of experiments carried out, which have made a novel contribution to knowledge in the fields of Human-Computer Interaction, Psychology of Programming, and Visual Programming Languages

Mixed-methods research: a new approach to evaluating the motivation and satisfaction of university students using advanced visual technologies

The final publication is available at link.springer.comA mixed-methods study evaluating the motivation and satisfaction of Architecture degree students using interactive visualization methods is presented in this paper. New technology implementations in the teaching field have been largely extended to all types of levels and educational frameworks. However, these innovations require approval validation and evaluation by the final users, the students. In this paper, the advantages and disadvantages of applying mixed evaluation technology are discussed in a case study of the use of interactive and collaborative tools for the visualization of 3D architectonical models. The main objective was to evaluate Architecture and Building Science students’ the motivation to use and satisfaction with this type of technology and to obtain adequate feedback that allows for the optimization of this type of experiment in future iterations.Postprint (author’s final draft

Towards a tool for the subjective assessment of speech system interfaces (SASSI)

Applications of speech recognition are now widespread, but user-centred evaluation methods are necessary to ensure their success. Objective evaluation techniques are fairly well established, but previous subjective techniques have been unstructured and unproven. This paper reports on the first stage of the development of a questionnaire measure for the Subjective Assessment of Speech System Interfaces (SASSI). The aim of the research programme is to produce a valid, reliable and sensitive measure of users' subjective experiences with speech recognition systems. Such a technique could make an important contribution to theory and practice in the design and evaluation of speech recognition systems according to best human factors practice. A prototype questionnaire was designed, based on established measures for evaluating the usability of other kinds of user interface, and on a review of the research literature into speech system design. This consisted of 50 statements with which respondents rated their level of agreement. The questionnaire was given to users of four different speech applications, and Exploratory Factor Analysis of 214 completed questionnaires was conducted. This suggested the presence of six main factors in users' perceptions of speech systems: System Response Accuracy, Likeability, Cognitive Demand, Annoyance, Habitability and Speed. The six factors have face validity, and a reasonable level of statistical reliability. The findings form a userful theoretical and practical basis for the subjective evaluation of any speech recognition interface. However, further work is recommended, to establish the validity and sensitivity of the approach, before a final tool can be produced which warrants general use

HEBE: Highly Engaging eBook Experiences

Despite more and more books are made available in electronic format and technology is increasingly present in children’s everyday life, thus far the potential of the electronic book (eBook) medium has been only partially exploited. With the Highly Engaging eBook Experiences (HEBE) project we studied how to design and evaluate eBooks for children with the goal of making the reading experience more engaging. The project began with an investigation of the many facets that characterize the reading experience of children in order to understand how it could possibly be enhanced by electronic books. In a later stage an intergenerational design team used different techniques of Cooperative Inquiry to explore a range of design ideas. Then, based on those ideas, we developed a prototype of enhanced eBook and elaborated a shortlist of design recommendations that are intended to help designers in creating more engaging eBooks. The research project ended with a stage of evaluation where children’s User Experience with the eBook prototype was assessed. We took inspiration from Csikszentmihalyi’s Flow theory to define a benchmark for evaluating the reading experience. Then, by means of the Experience Sampling Method (ESM), we investigated and collected data on the reading experience of two groups of children, one of which read an eBook enhanced following our design recommendations while the other read a basic version of the same eBook. Following a mixed-method approach, with quantitative analysis we verified whether participants who read the enhanced eBook had a better reading experience, while with qualitative analysis we tried to understand why. The results of the evaluation showed that that an eBook designed following our design recommendations may have a positive effect on children’s reading experience by making it more engaging

Proceedings of the Sixth Danish Human-Computer Interaction Research Symposium.

Proceedings of theSixth Danish Human-Computer Interaction Research Symposium.Aarhus, Denmark, November 15, 200

Ordinary user experiences at work: a study of greenhouse growers

We investigate professional greenhouse growers’ user experience (UX) when using climate-management systems in their daily work. We build on the literature on UX, in particular UX at work, and extend it to ordinary UX at work. In a ten-day diary study, we collected data with a general UX instrument (AttrakDiff), a domain-specific instrument, and interviews. We find that AttrakDiff is valid at work; its three-factor structure of pragmatic quality, hedonic identification quality, and hedonic stimulation quality is recognizable in the growers’ responses. In this paper, UX at work is understood as interactions among technology, tasks, structure, and actors. Our data support the recent proposal for the ordinariness of UX at work. We find that during continued use UX at work is middle-of-the-scale, remains largely constant over time, and varies little across use situations. For example, the largest slope of the four AttrakDiff constructs when regressed over the ten days was as small as 0.04. The findings contrast existing assumptions and findings in UX research, which is mainly about extraordinary and positive experiences. In this way, the present study contributes to UX research by calling attention to the mundane, unremarkable, and ordinary user experiences at work