Showing papers in "International Journal of Human-computer Studies \/ International Journal of Man-machine Studies in 2001"

Methods to support human-centred design

Abstract: This paper notes the importance of usable systems and promotes the process of human-centred design as a way to achieve them. Adopting the framework of ISO 13407, each of the main processes in the human-centred design cycle is considered in turn along with a set of usability methods to support it. These methods are briefly described with references to further information. Each set of methods is also presented in a table format to enable the reader to compare and select them for different design situations.

International standards for HCI and usability

Abstract: Over the last 15 years, a comprehensive range of international standards has been developed to define the general principles of user-centred design and good practice in user interface design. Most of the standards specify general principles rather than the precise details of the interface. The paper briefly describes how standards are created and reviews the definitions of usability. HCI and usability standards are described in the categories: usability definitions, use in context, software interface and interaction, hardware interface, documentation, the development process and capability of the organization. The applicability of the standards is discussed.

What do web users do? An empirical analysis of web use

Abstract: This paper provides an empirical characterization of user actions at the web browser. The study is based on an analysis of 4 months of logged client-side data that describes user actions with recent versions of Netscape Navigator. In particular, the logged data allow us to determine the title, URL and time of each page visit, how often they visited each page, how long they spent at each page, the growth and content of bookmark collections, as well as a variety of other aspects of user interaction with the web. The results update and extend prior empirical characterizations of web use. Among the results we show that web page revisitation is a much more prevalent activity than previously reported (approximately 81% of pages have been previously visited by the user), that most pages are visited for a surprisingly short period of time, that users maintain large (and possibly overwhelming) bookmark collections, and that there is a marked lack of commonality in the pages visited by different users. These results have implications for a wide range of web-based tools including the interface features provided by web browsers, the design of caching proxy servers, and the design of efficient web sites.

Towards a cognitive approach to human-machine cooperation in dynamic situations

Abstract: Human-computer interaction research has produced consistent results bearing on a well-established body of knowledge in cognitive science. In contrast, the new research domains of computer- supported cooperative work (CSCW) or human?machine cooperation are harder to develop because the problems to be solved are more complex and the theoretical frameworks more heterogeneous. However, dynamic situations with high temporal constraints create occasions where small teams (including humans and machines) can cooperate on an almost cognitive basis, reducing social or emotional effects. This paper reviews the state of the art on cognitive cooperation to extend an individual cognitive architecture and deal with these situations, combining private and cooperative activities that are highly task-oriented. Cooperation is taken as the management of interference between individual activities to facilitate the team members' sub-tasks and the team's common task when there is one. This review of the literature is a step towards a theoretical approach that could be relevant to evaluate cooperation and to design assistance in diverse domains such as air traffic control or aircraft piloting.

Studying the language and structure in non-programmers' solutions to programming problems

Abstract: Programming may be more difficult than necessary because it requires solutions to be expressed in ways that are not familiar or natural for beginners. To identify what is natural, this article examines the ways that non-programmers express solutions to problems that were chosen to be representative of common programming tasks. The vocabulary and structure in these solutions is compared with the vocabulary and structure in modern programming languages, to identify the features and paradigms that seem to match these natural tendencies as well as those that do not. This information can be used by the designers of future programming languages to guide the selection and generation of language features. This design technique can result in languages that are easier to learn and use, because the languages will better match beginners' existing problem-solving abilities.

Context of Use within usability activities

Abstract: Designing for usability involves establishing user requirements for a new system or product, developing design solutions, prototyping the system and the user interface, and testing it with representative users. However, before any usability design or evaluation activity can begin, it is necessary to understand the Context of Use for the product, i.e. the goals of the user community, and the main user, task and environmental characteristics of the situation in which it will be operated. This paper describes the background to, and importance of, understanding Context of Use, and presents a process for performing a context analysis. The method described is particularly aimed at non-experts in the area of user-centred design and evaluation.

ACT-R/PM and menu selection

Abstract: Understanding the interaction of a user with a designed device such as a GUI requires clear understanding of three components: the cognitive, perceptual and motor capabilities of the user, the task to be accomplished and the artefact used to accomplish the task. Computational modeling systems which enable serious consideration of all these constraints have only recently begun to emerge. One such system is ACT-R/PM, which is described in detail. ACT-R/PM is a production system architecture that has been augmented with a set of perceptual-motor modules designed to enable the detailed modeling of interactive tasks. Nilsen's (1991) random menu selection task serves two goals: to illustrate the promise of this system and to help further our understanding of the processes underlying menu selection and visual search. Nilsen's original study, two earlier models of the task, and recent eye-tracking data are all considered. Drawing from the best properties of the previous models considered and guided by information from the eye-tracking experiment, a series of new models of random menu selection were constructed using ACT-R/PM. The final model provides a zero-parameter fit to the data that does an excellent, though not perfect, job of capturing the data.

User attitude as a mediator of learning performance improvement in an interactive multimedia environment

Abstract: Multimedia technology-based interactive learning/training programs have recently emerged as major tools for learning in educational settings (schools), at home and for training in corporations. Multimedia aspects and an ability to interact with the programs are claimed to enhance the learning experiences. A central thesis of this study is that such “interactive multimedia learning systems” would significantly improve users' attitudes, and that this, in turn, would enhance their learning achievement. An additional thesis of the study is that the “learning style” of the users will moderate the relationship between interactivity and attitude. This article reports the findings of a controlled quasi-experimental study of the influences of “interactivity” on six different dimensions of user attitude (content, format, user-control, feedback, ease of use and motivation) and performance improvement (achievement-gain). The results indicate that interactivity positively influences user attitude, and some dimensions of attitude translate into enhanced user performance. The study finds some interesting support for the moderating effects of learning styles. Implications and future research directions are discussed.

The influence of reading speed and line length on the effectiveness of reading from screen

Abstract: With such a large volume of material accessible from the World Wide Web, there is an urgent need to increase our knowledge of factors influencing reading from screen. We investigate the effects of two reading speeds (normal and fast) and different line lengths on comprehension, reading rate and scrolling patterns. Scrolling patterns are defined as the way in which readers proceed through the text, pausing and scrolling. Comprehension and reading rate are also examined in relation to scrolling patterns to attempt to identify some characteristics of effective readers. We found a reduction in overall comprehension when reading fast, but the type of information recalled was not dependent on speed. A medium line length (55 characters per line) appears to support effective reading at normal and fast speeds. This produced the highest level of comprehension and was also read faster than short lines. Scrolling patterns associated with better comprehension (more time in pauses and more individual scrolling movements) contrast with scrolling patterns used by faster readers (less time in pauses between scrolling). Consequently, effective readers can only be defined in relation to the aims of the reading task, which may favour either speed or accuracy.

Predicting the effects of in-car interface use on driver performance

Abstract: While researchers have made great strides in evaluating and comparing user interfaces using computational models and frameworks, their work has focused almost exclusively on interfaces that serve as the only or primary task for the user. This paper presents an approach of evaluating and comparing interfaces that users interact with as secondary tasks while executing a more critical primary task. The approach centers on the integration of two computational behavioral models, one for the primary task and another for the secondary task. The resulting integrated model can then execute both tasks together and generate a priori predictions about the effects of one task on the other. The paper focuses in particular on the domain of driving and the comparison of four dialing interfaces for in-car cellular phones. Using the ACT-R cognitive architecture (Anderson & Lebiere, 1998) as a computational framework, behavioral models for each possible dialing interface were integrated with an existing model of driver behavior (Salvucci, Boer & Liu, in press). The integrated model predicted that two different manual-dialing interfaces would have significant effects on driver steering performance while two different voice-dialing interfaces would have no significant effect on performance. An empirical study conducted with human drivers in a driving simulator showed that while model and human performance differed with respect to overall magnitudes, the model correctly predicted the overall pattern of effects for human drivers. These results suggest that the integration of computational behavioral models provides a useful, practical method for predicting the effects of secondary-task interface use on primary-task performance.

Rethinking the evaluation of algorithm animations as learning aids

Abstract: One important aspect of creating computer programs is having a sound understanding of the underlying algorithms used by programs. Learning about algorithms, just like learning to program, is difficult, however. A number of prior studies have found that using animation to help teach algorithms had less beneficial effects on learning than hoped. Those results surprise many computer science instructors whose intuition leads them to believe that algorithm animations should assist instruction. This article reports on a study in which animation is utilized in more of a “homework” learning scenario rather than a “final exam” scenario. Our focus is on understanding how learners will utilize animation and other instructional materials in trying to understand a new algorithm, and on gaining insight into how animations can fit into successful learning strategies. The study indicates that students use sophisticated combinations of instructional materials in learning scenarios. In particular, the presence of algorithm animations seems to make a complicated algorithm more accessible and less intimidating, thus leading to enhanced student interaction with the materials and facilitating learning.

Internet dependency and psychosocial maturity among college students

Abstract: One salient impact of information technology on students' lives is the ever-increasing use of the Internet. Although there exist many reports in the media regarding the unhealthy Internet use among students, research is still limited and has mainly relied upon on-line self-selected reports on Internet dependency or “Internet addiction”. This paper attempts to look into the alleged Internet dependency within the Eriksonian psychosocial development framework. The results of a survey of the Internet use among 217 students in an Australian regional university are reported. The measures of patterns of the Internet use were correlated with that of psychosocial maturity and self-efficacy. The results showed that the Internet dependency seemed to be independent of the psychosocial maturity and the general perceived self-efficacy. A factor analysis extracted six factors from a set of 28 Internet experience-related questions and indicated that the Internet dependency could be of a multifaceted nature. The findings and their implications were discussed and a contextual perspective was proposed.

The user action framework

Abstract: Although various methods exist for performing usability evaluation, they lack a systematic framework for guiding and structuring the assessment and reporting activities. Consequently, analysis and reporting of usability data are ad hoc and do not live up to their potential in cost effectiveness, and usability engineering support tools are not well integrated. We developed the User Action Framework, a structured knowledge base of usability concepts and issues, as a framework on which to build a broad suite of usability engineering support tools. The User Action Framework helps to guide the development of each tool and to integrate the set of tools in the practitioner's working environment. An important characteristic of the User Action Framework is its own reliability in term of consistent use by practitioners. Consistent understanding and reporting of the underlying causes of usability problems are requirements for cost-effective analysis and redesign. Thus, high reliability in terms of agreement by users on what the User Action Framework means and how it is used is essential for its role as a common foundation for the tools. Here we describe how we achieved high reliability in the User Action Framework, and we support the claim with strongly positive results of a summative reliability study conducted to measure agreement among 10 usability experts in classifying 15 different usability problems. Reliability data from the User Action Framework are also compared to data collected from nine of the same usability experts using a classic heuristic evaluation technique.

Ubiquitous computing within cars

Abstract: Increasingly, computing and communications-based technologies are being implemented within cars. There is a need for fundamental research and development to ensure that the control interfaces for future cars require minimal visual demands. The needs, abilities and preferences of drivers (in particular older drivers) are clearly a prime focus, as part of a user-centred design approach. In addition, it is argued that much can be learnt from the experience and strategies adopted by people who are blind or have low vision (a non-user group). The paper sets out a number of research questions regarding the inclusion of such people in the design process of future automobiles.

The improvement of human-centred processes-facing the challenge and reaping the benefit of ISO 13407

Abstract: Human-centred design processes for interactive systems are defined in ISO 13407 and the associated ISO TR 18529. The publication of these standards represents a maturing of the discipline of user-centred design. The systems development community see that (at last) Human Factors has processes which can be managed and integrated with existing project processes. This internationally agreed set of human-centred design processes provides a definition of the capability that an organization must possess in order to implement user-centred design effectively. It can also be used to assess the extent to which a particular development project employs user-centred design. As such, it presents a challenge to the Human Factors community, and indeed a definition of good practice may even be regarded by some as an unwelcome constraint. This paper presents the background to the process-level definition of user-centred design and describes how it relates to current practice. The challenges, benefits and use of a defined human-centred design process are presented. The implications for Human Factors and other disciplines are discussed. In Appendices A?D, the process terminology and the contents of ISO 13407 and ISO TR 18529 are described in more detail, and three examples are given (in Appendix D) of using this process improvement approach to improve the actual design methods in three organizations.

New product development by eliciting user experience and aspirations

Abstract: Industrial design training is embracing the need for designers to elicit user needs in order to support the development of successful new products. This paper highlights the collaboration of an ergonomist and two industrial designers in the development of a range of mainstream domestic consumer products. It documents the experiences gained in applying and adapting focus group techniques to inform the designing process directly, and illustrates how a variety of techniques (e.g. product handling and product personality profiling) can be incorporated to elicit user needs, aspirations and emotions.

Effects of training and representational characteristics in icon design

Abstract: Icons are a very important component of graphical user interfaces. However, icon design is still predominantly artistic in nature and as a result icon selection is generally based on usability evaluations after a set of alternative icons are developed. This process tends to be time-consuming and costly. In this research, we address the issues ofwhat should be depicted in an icon, given the function it should represent, and how training affects the performance of novice users when using an iconic interface. A set of 36 concrete icons (12 functions) were selected and tested with a total of 30 participants. The experimental results indicate that complete representations are generally superior for both untrained and trained participants. Results also show that trained participants had shorter response times when compared to untrained participants. Further analysis suggests that ambiguity, uniqueness and dominance are three important aspects to consider when designing and developing icons. Applications of this research include the design of appropriate icons for graphical user interfaces prior to usability testing and the importance of a short training period to illustrate the composition of an icon in an effort to improve the mental model associated with each design.

Prototyping for usability of new technology

Abstract: This paper argues that it is possible to gain good design information from low-cost user trials of low-fidelity prototypes early in the design process, and that simple prototyping is a valuable tool in the user-centred design of new technology especially “smart” consumer products. The value of that design information depends on the stage of the design process at which user testing is carried out and the associated level of realism or fidelity of the prototype. The first stages involve testing simple prototypes which examine the cognitive, or information processing, needs of the user, followed by higher-fidelity prototypes which examine the physical (visual, auditory and tactile) needs of the user.The results of four studies are discussed to illustrate: the extent and nature of the design information gathered, the relative merits of varying the fidelity of the prototypes, and the benefits and costs associated with using different levels of fidelity of prototypes in a user-centred approach to design. Finally, and based on that discussion, an appropriate and practical design strategy is suggested.

Requirements trawling

Abstract: If you approach someone in the street and ask for directions then, provided that person knows the way and speaks the same language as you do, it should be easy for him to help you. But often, when you try to follow the directions, you become more confused and lost. Perhaps the person giving the directions has assumed that you know about a local landmark or has forgotten to mention that there is another small street on the left before the one you are seeking. Or maybe the director has not understood your request and has sent you to a place with a similar name?there are so many reasons why the transfer of information from one person to another is fraught with difficulties.When you try to discover the requirements for any kind of product the difficulties are even more complex because the source of the requirements is not just one person, it is all of the people who are stakeholders in the project. Moreover, all of these people have their own view of what is important, along with their own experience, prejudices and views of the world. Considering the variations between your sources of requirements (stakeholders) it makes sense to have a variety of techniques for discovering the requirements. We call these as trawling techniques because, like fishing, we run a net through the organization and trap as many requirements as we can. Then, using the appropriate technique, we identify the relevant requirements (the juicy codfish) and separate them from the irrelevant (the minnows). We also look for rare and amazing fish that nobody has ever seen before. We are not just concerned with finding existing requirements, we are also concerned with generating new requirements by using techniques that encourage creativity. This paper summarizes a number of techniques that we have found useful when trawling for requirements.

Embodied models as simulated users: introduction to this special issue on using cognitive models to improve interface design

Abstract: Cognitive models provide a means for applying what is known from psychology to the design of interfaces, thereby improving their quality and usability. Existing uses of models include predicting time and errors for users to perform tasks, acting as embedded assistants to help users perform their tasks, and serving as surrogate users. Treating the design of human–computer interfaces as a form of engineering design requires the development and application of user models. A recent trend is for models to be built within the fixed framework of a cognitive architecture, which has been extended by the addition of simulated eyes and hands, enabling the construction of embodied models. Being embodied allows models to interact directly with interfaces. The resulting models can be used to evaluate the interfaces they use, and serve as explanations of users' behavior. The papers in this Special Issue point to a new route for the future, one in which models built within embodied cognitive architectures provide information for the design of better interfaces.

Graphic and numerical methods to assess navigation in hypertext

Abstract: User navigation has been a central theme in both theoretical and empirical work since the earliest days of hypertext research and development. Studies exploring user navigation have, however, tended to rely on indirect navigational measures and have rarely tried to relate navigation to performance-solving problems or locating information. This paper proposes methods that lead to a more direct representation and analysis of user movement in hypertext and empirically explores the relationship of these measures to performance in a hypertext search task. Results of the study indicate that the proposed graphical and numerical methods have empirical significance and may be useful in assessing and modeling user navigation.

How do operators monitor a complex, dynamic work domain? The impact of control room technology

Abstract: This article describes part of a research programme whose goal is to develop a better understanding of how operators monitor complex, dynamic systems under normal operations. In a previous phase, field observations were made at two older nuclear power plant control rooms (CRs) consisting primarily of analogue, hard-wired instrumentation. In this phase, additional field observations were conducted in a newer computer-based CR to determine the impact of CR technology on operator monitoring. Eleven different operators were observed in situ for a total of approximately 88 h. The findings indicate that there are many similarities in the monitoring strategies adopted by operators in the two types of CRs. However, in most cases, these same strategies are performed using different behaviours, thereby showing the shaping effect of the CR technology. A new way of conceptualizing the difference between traditional analogue CRs and modern computer-based CRs is proposed.

Assessing users' subjective quality of experience with the world wide web

Abstract: Contemporary information technology?(IT)-related research has focused on use or user acceptance as a key dependent measure for valuing IT. By understanding the determinants of IT use, we gain descriptive information about successful IT, and prescriptive information for better deploying IT resources and improving their utility. Although there are several competing theories regarding IT use, research findings often cite their inability to account for temporal changes in usage behaviors. Furthermore, contemporary human?computer interaction perspectives often focus on the robust and growing literature surrounding usability and likeability; however, few studies have provided insight into the components of, or antecedents to, the utility dimension. This research attempts to address these gaps by introducing the construct of users'quality of experience as a potential mediator between the determinants of use and actual usage behaviors and their outcomes. A pilot survey concerning Internet usage generated potentially relevant items which were later refined into a questionnaire assessing each item's relative importance to perceptions of quality of experience. Initial indications suggest 10 of the items represent a temporally stable and unidimensional construct. Findings are also interpreted within the context of IT and cognitive/behavioral science perspectives, further providing for face validity of the quality of experience construct.

Evaluating the human-machine interface to vehicle navigation systems as an example of ubiquitous computing

Abstract: In-vehicle navigation systems are an example of ubiquitous computing, where the computing facility is embedded in an everyday object (car) for an everyday task (driving). The maturing navigation systems market of the last 10 years has prompted academic and commercial research into the human?machine interface (HMI) for these systems. A significant body of research now exists in this specialized area and a contribution has been made towards guidelines for interface design. This paper presents an overview of evaluation methods used to date (in terms of context of use, techniques, measures and evaluators) and the pros and cons of the different approaches. It ends with a discussion of how the resulting knowledge can assist in the evaluation of other ubiquitous technologies.

Implications of buyer decision theory for design of e-commerce websites

Abstract: In the rush to open their website, e-commerce sites too often fail to support buyer decision-making and search, resulting in a loss of sale and the customer's repeat business. This paper reviews why this occurs and the failure of many B2C and B2B website executives to understand that appropriate decision support and search technology cannot be fully bought off-the-shelf. Our contention is that significant investment and effort is required at any given website in order to create the decision support and search agents needed to properly support buyer decision-making. We provide a framework to guide such effort (derived from buyer behavior choice theory); review the open problems that e-catalog sites pose to the framework and to existing search engine technology; discuss underlying design principles and guidelines; validate the framework and guidelines with a case study; and discuss lessons learned and steps needed to better support buyer decision behavior in the future. Future needs are also pinpointed.

Virtual reality for interactive training

Abstract: The closing years of the 20th Century were associated with the advent of affordable Windows-based technologies for popular computer configurations, from powerful PCs in the home to workstations for small business communities. Such machines are readily capable of exploiting the power of real-time interactive 3D computer graphics, popularly referred to asvirtual reality (VR). VR has rapidly evolved into a technology that today offers a cost-effective means of supporting the development of human skills in all manner of applications, from automotive engineering to defence, surgery to education, retail, petrochemical exploration, and heritage to micro-robotics. This paper reviews some of the important human performance results to emerge from the academic and commercial application of VR technologies, and notes some ergonomic issues to be resolved in developing techniques for training and performance assessment that can be used cheaply and efficiently in industrial settings.

Informing the design of a virtual environment to support learning in children

Abstract: This paper describes how different kinds of research activities (theory building and application, exploratory and experimental studies, prototyping, user testing) are instrumental for informing the design of virtual environments. We show how general user-centred design methods can be used when dealing with specific issues concerned with the properties of virtual environments. To illustrate our approach we describe how we have designed a virtual theatre for young children to support learning through playing. We conclude with a general discussion of the core issues that need to be considered when designing virtual environments.

Theme-based content analysis

Abstract: Virtual environment and multimedia technology are developing rapidly in many areas. These include visual complexity, the opportunity to provide multi-sensory input and output, affordability and a variety of system designs and applications. Involving the users in the design and development process can result in more appropriate and usable interfaces. In addition, an iterative evaluation throughout the process of technology development can result in a large amount of useful information being gathered from users. However, there can be problems with this?the data collection and analysis process can be time consuming; it can be difficult to report information back to the developers in a meaningful form, and thus the results of the evaluation may not get incorporated into interface design; and some evaluation techniques can be specific to the application (e.g. assessment of learning from an educational virtual environment application) or user group (e.g. people with learning disabilities).This paper presents an evaluation method that has been successfully used in virtual environment and multimedia evaluation at the Virtual Reality Applications Research Team (VIRART), and has overcome some of these problems. Theme-based content analysis (TBCA) is a qualitative method that provides useful, detailed information about user opinions or behaviour, and can also provide general indications of results in the user population by the grouping of data into meaningful categories. A number of different data collection methods can be used (e.g. short interview, open-ended questionnaire questions, observation) allowing the time and expertise of the virtual environment researcher to be most usefully employed, and the needs and abilities of the user population to be met. The analysis process is less time-consuming, and allows both summarization of the results and retention of the raw data. As described in the paper, this flexible method can be applied in a number of different circumstances, with a variety of different virtual reality technologies (desktop, projection or head mounted display (HMD) systems). In addition, the results from this method can be presented in a simple format to allow an easy feedback of user opinions and behaviours to virtual environment developers, providing contextual examples and an indication of the proportion of users experiencing usability problems. This facilitates a direct input of the evaluation data into the virtual environment development process.

A perception/action substrate for cognitive modeling in HCI

Abstract: This article describes a general-purpose programmable substrate designed to allow cognitive modeling systems to interact with off-the-shelf interactive applications. The substrate, called VisMap, improves on conventional approaches, in which a cognitive model interacts with a hand-constructed abstraction, an artificial simulation or an interface tailored specifically to a modeling system. VisMap can be used to construct static scenarios for input to a cognitive model, without requiring its internal modification; alternatively, the system can be integrated with a cognitive model to support direct control of an application.

An exploratory study of program comprehension strategies of procedural and object-oriented programmers

Abstract: This exploratory study examines the nature of program understanding strategies employed during a series of comprehension and maintenance activities carried out over time. Two dimensions of comprehension were examined: the direction of comprehension and the breadth of comprehension. Thirty expert procedural and object-oriented (OO) programmers studied a program and then performed modifications during two sessions held 1 week apart. The results showed that the direction of comprehension was mixed. The OO programmers tended to use a strongly top-down approach to program understanding during the early phase of familiarization with the program but used an increasingly bottom-up approach during the subsequent maintenance tasks. The procedural programmers used a more bottom-up orientation even during the early phase, and this bottom-up approach became even stronger during the maintenance tasks. The breadth of the programmers' comprehension was found to be greater for the procedural programmers than for the object-oriented programmers. However, after carrying out a series of tasks, all programmers had examined the majority of the program code. The results suggest that, regardless of paradigm, expert programmers eventually build a broad systematic, rather than a localized, view of a program over time.