Implications For Interface Design Research Articles

The Effect of Age-Related Cognitive Differences, Task Complexity and Prior Internet Experience in the Use of an On-line Grocery Shop

This study examined navigation and search in an on-line grocery store, and how solving those tasks was related to subjects' age, spatial ability, working memory, computer- and Internet experience. Task complexity was also included in the design of the experiment. In the study 48 subjects participated, there was one group of elderly and one group of younger subjects. The results showed that the elderly subjects needed more time to complete the tasks. Both age groups spent more time to find the items in the complex task, but there were also age differences for the complex task, where the elderly subjects spent more time with the complex task. It turned out that age, spatial visualisation ability and working memory had the strongest impact on performance for the complex task. For the easy task, on the other hand, Internet experience had the strongest impact on performance. Though this may seem discouraging to elderly users, it was also the case that the elderly, less experienced, subjects underestimated the time they spent performing the tasks. Thus, even if it took long time to solve the tasks, these elderly users did not experience it as such. Finally, implications for interface design of on-line grocery stores are discussed.

Naïve and experienced judgments of stimuluS—Response compatibility: implications for interface design

Many design guidelines encourage maintaining stimulus—response compatibility whenever possible. Payne found that naïve judgments for different stimulus—response (S—R) mappings were not very accurate, and suggested that designers may not be able to predict whether a particular display-control configuration will lead to better performance than another. Three experiments were conducted to determine whether naïve judgments for two-choice tasks in which stimuli and responses involve left—right spatial information are sensitive to (a) the influence of S—R mode relations and (b) pure versus mixed presentation of compatible and incompatible mappings. Initial performance judgments for these conditions were not very accurate, nor were those for four-choice tasks of the type studied by Payne, but subjects' estimates of performance improved with relatively little experience using the different S—R configurations.

A pilot study exploring electronic (or e-mail) mail in users with acquired cognitive-linguistic impairments

This paper reports the results of an exploratory study into the usability of a simplified e-mail interface for eight individuals with acquired cognitive-linguistic impairments. Participatory Action Research, a qualitative research method, was used to capture the range of performance variables and to emphasize a 'user-centred' approach to the research process. The participants were asked to read and reply to e-mails across four writing prompt conditions. An analysis of errors and participant preferences for the prototype e-mail system was conducted. Errors fell into two general categories: (1) computer usability (e.g. conceptual understanding of mouse/cursor operation) and (2) message composition (e.g. generating ideas for a message). Participant preferences for the writing prompt conditions varied considerably. All participants endorsed the use of customized e-mail interfaces as a means of connecting with friends and family, thereby reducing social isolation. Implications for interface design, rehabilitation and future research into assistive technology are discussed.

Spatially Oriented and Person Oriented Thinking—Implications for User Interface Design

Identifying aspects of individual cognitive variation of relevance for the design of instructional multimedia is argued to be an important research task. A study is presented in which two candidates, person oriented thinking and spatially oriented thinking, were explored. Two different user interfaces to an application, one with a person related format and the other with a spatial format, were used, and participants were asked to choose between the two versions and to motivate their choice. Two main tendencies appeared. Interface preferences tended to correlate with style of thought as well as with gender.

A Field Study of Collaborative Work in Network Management: Implications for Interface Design

To inform the design of interfaces in real-time network management, a field study of telecommunication engineers was conducted at a corporate network operating centre. Eighty hours of direct observations, spanning ten different shifts, were carried out. This study focused on the nature of collaboration between network managers and stakeholders who were internal and external to their organization, how they communicated with one another, and how network managers distributed responsibilities and information. The characteristics of network management, and thus the collaboration, differ substantially in some ways from other complex work domains. This work helped to identify novel opportunities for enhancing and redesigning current interfaces to provide better support for communication and coordination in network operating environments.

Voice dialling can reduce the interference between concurrent tasks of driving and phoning

Previous research has found that using a mobile phone while driving can be detrimental to driving performance. Voice dialling has the potential to reduce the interference between concurrent tasks of driving and phoning. A laboratory experiment was designed to test two variations of a speech interface against a standard manual interface. Forty-eight participants carried out driving-related tasks while simultaneously dialling familiar numbers. The speech interfaces significantly reduced both tracking error and the reaction time to peripheral targets, compared to the manual interface. Despite an increase in dialling transaction times, speech was preferred by users, and felt to be less demanding than manual control. The speech interface with visual plus auditory feedback of recognition results performed worse than the audio-only condition. The results are explained in terms of the physical and cognitive demands of phoning while driving, and have important implications for interface design.

Factors Affecting Memory for Dynamically Changing System Parameters: Implications for Interface Design

Factors that delimit the performance of human operators monitoring dynamic information are essential considerations for interface designers. Using a procedure pioneered by Yntema and colleagues (1962, 1960), the present research examines the effect of the configuration of visual information (i.e., whether the subject is presented with multiple objects, mapped to a single attribute or multiple attributes mapped to a single object) on subjects' memory for that information. Results suggest that the similarity between bits of information, rather than how the information is organized, is the critical factor in determining memory performance for dynamic information. These results suggest implications for the design of visual displays.

Influences of general computer experience and age on library database search performance

Two experiments examined the effects of general computer experience and age on library system search performance among novice library system users. Twenty younger adults (10 with high and 10 with low computer experience) and 20 older adults (10 with low and 10 with no computer experience) performed 10 search tasks of varying difficulty. Search success, syntax errors, database field specifications, keyword specifications, and use of Boolean operators were examined. Among younger novices, high computer experience was associated with slightly better performance than low computer experience. Among older novices, having some computer experience was associated with much better performance than no computer experience. Older computer users showed lower overall success rates, made more syntax and field specification errors, and demonstrated poorer understanding of Boolean logic and keyword matching algorithms than younger adults with similar computer experience. Implications for interface design and training interventions for novice on-line library system users are discussed.

Effects of Humor in Task-Oriented Human-Computer Interaction and Computer-Mediated Communication: A Direct Test of SRCT Theory

Little published research exists on whether humor is a positive or a negative in task-oriented human-computer interaction (HCI). The prevailing notion is that humor distracts users, wastes their time, and may cause them to take their work less seriously. Two experiments examined the effects of humor in task situations involving HCI and computer-mediated communication (CMC). The studies used the same two-condition (humor or control) between-subjects design and essentially the same experimental method. Thus, data from the studies can be compared in a direct test of the social responses to communication technologies (SRCT) claim that people respond to humans and computers in identical ways. In the first experiment, participants worked on a task, ostensibly with another person in a different room, via a networked computer (CMC). All participants received preprogrammed comments, differing only in whether they contained humor. Humor participants rated the "other person" as more likable and reported greater cooperation with and similarity to this other person. They also made more jokes and responded more sociably. Task time and the amount of effort participants put into the task were unaffected by humor. In the second experiment, participants were told they were interacting with a computer in another room (HCI). The results from Experiment 2 were generally consistent with those from Experiment 1; however, HCI participants were less sociable, demonstrated less mirth, felt less similar to their interaction partner, and spent less time on the task. The results suggest both that humor may enhance likability of an interface and that SRCT theory should be revised. Implications for user-interface design and guidelines for the use of humor in HCI are discussed.

The Value of Assistance: An Onboard Diagnostic Interface for Navy Rotorcraft Operations

User interfaces capable of providing intelligent assistance to people are becoming a viable solution to the problem of human interaction with complex systems. In this paper we present a number of important factors and discuss their implications for intelligent assistance, with specific emphasis on user interface design. We will present those factors in the context of empirical data obtained during two studies of aircrew performance conducted in a helicopter simulator. The paper will begin with a discussion of the background to the project, and then turn to the factors revealed in the two studies and the data which indicated to us the importance of those factors. The paper will conclude with a discussion of the implications for user interface design, and our plans for further research and development in this area.

The Psychology of Attention

MIT Press, 1998. £38.50 (xiv + 494 pages)ISBN 0 262 16165 6Patrick Cavanagh (1998) recently noted that research on attention has ‘increased by 400% relative to other categories of cognitive publications’ over the past two decades1xAttention: a peaceful haven for studies of conscious information processing. Cavanagh, P. Perception. 1998; 27: 23See all

Representation still matters: Cognitive engineering and user interface design

With the increased utilization of cognitive models for designing user interfaces several disciplines started to contribute to acquiring and representing knowledge about users, artifacts, and tasks. Although a wealth of studies already exists on modeling mental processes, and although the goals of cognitive engineering have become quite clear over the last decade, essential epistemological and methodological issues in the context of developing user interfaces have remained untouched. However, recent challenging tasks, namely designing information spaces for distributed user communities, have led to a revival of well known problems concerning the representation of knowledge and related issues, such as abstraction, navigation through information spaces, and visualization of abstract knowledge. All of these issues are associated with mental processes and thus, might become part of cognitive models. In this paper we reveal epistemological and methodological assumptions in the field of cognitive modeling as well as their implications for user interface design. It turns out that in order to achieve the goal of developing human-oriented (in contrast to technology-driven) human-computer interfaces developers have to develop knowledge of the structure and the representational dynamics of the cognitive systems which are interacting with the computer. We show that in a first step it is necessary to study and investigate the different levels and forms of representation that are involved in the interaction processes between computers and human cognitive systems. We propose a hybrid user modeling approach as part of the task-based development procedure in TADEUS (Task Analysis/Design/End User Systems). The hybrid approach does not only enable the representation of functional roles end users have to perform, but also how end users perform these roles, i.e. the representation and reflection, if not prediction of their behavior. This way, holistic system development that equally takes into account the organizational requirements and the end user reality at work places is facilitated.

Individual Differences in the Use of Command Line and Menu Computer Interfaces

This article presents an experimental investigation of the process of computer-based command generation. The comparative cognitive demands imposed by menu and command line interfaces are examined in relation to individual differences in expertise and cognitive ability. Three-way interactions between associative memory, expertise, and command generation method indicated similarities in the performance of expert participants with low associative memory and that of novices. Spatial memory also interacted with expertise, with novices with low spatial memory performing more poorly than any other group. Implications for interface design are considered.

Spatial ability and visual navigation: an empirical study

In this paper, we describe an empirical study of individuals' spatial navigation strategies and a number of performance and preference measures with regard to the design of a novel 3D visualisation. The underlying semantic space of the user interface consists of a collection of papers from the three most recent ACM SIGCHI conference proceedings, visualised as a virtual reality network. This network was automatically constructed based on semantic similarities derived from latent semantic analysis. We studied die search strategies and general preferences of eleven subjects who used this system to find papers on various topics. The study has led to a number of interesting findings, which should be valuable for designers and evaluators of 3D user interfaces. The results highlight the importance of structural elements in the design of a semantically based user interface, because search strategies of users relied heavily on these mechanisms in the design. The results of this study also demonstrate that we are able to characterise and learn from users search strategies in a visual environment strongly shaped by semantic relationships of the information content. Implications for user interface design based on users psychological models of a semantic space are described.

Computerized information retrieval: individual differences in the use of spatial vs nonspatial navigational information.

Although a number of experiments have demonstrated the importance of spatial ability as a predictor of computer-based performance, there is little evidence relating to the mechanics of this association or the implications for interface design. Two experiments on the relative importance of spatial and nonspatial semantic information within the context of computerized information retrieval are described. The first experiment indicated that spatial ability did not interact with the spatial information content of the computer interface. The second experiment indicated that the effects of spatial ability are attenuated when additional nonspatial semantic information is provided.

A Comparison of Graphical User Interface Widgets for Various Tasks

The purpose of the present study was to compare user performance, accuracy and preference while using standard user interface controls or “widgets” to complete specific types of tasks. Radio buttons were significantly faster, accurate, and preferred than any outer widget for the mutually exclusive selection tasks. For the non-mutually exclusive selection tasks, check boxes were significantly faster and preferred. These widgets were superior due to the fact that all possible options were initially visible. As the number of options increased, the time to complete each task also increased. A practitioner's table for selecting effective widgets for specific types of tasks is provided. Further implications for user interface design and research are discussed.

Computer-based system access by persons with disabilities: Differences in the effects of interface design on novice and experienced performance

It is well accepted that with even very simple tasks, a user's performance with a manual control device improves substantially over some period of time before stabilizing. Past studies with computer input devices have shown that the overall period of time required to learn to physically interact with a system is, however, generally quite short. For users with mobility impairments, however, not only may the overall physical learning phase be significantly longer than for nondisabled users, but certain features of the interface design may require a longer learning period than others. Depending on how different “initial” performance is from “practiced” performance, systems intended for “walk up and use” applications or casual use may need to be designed differently to allow easy access for persons with mobility impairments. Twenty persons with impaired hand and arm function (as a result of spinal cord injury) performed a target acquisition task with five manual computer input devices. Task completion times and errors were recorded. The results indicate that some devices and screen design features required significantly longer periods of time than others for the participants to become proficient at using them. The results also suggest not only that some physical design attributes negatively effect performance, but that the magnitude of the effects differ for “initial” performance and “practiced” performance. In fact, in some cases attributes which had no effect once performance had asymptoted were shown to have a significant effect on novice performance. The implications for interface design are discussed.

Experiences in providing a white pages directory service based on the X.500 standard

Abstract This paper is based on the author's experience of designing a white pages user interface to the X.500 Directory. The paper examines two issues. First, a number of problems arose during the design process which are perceived as being due to inadequacies in the 1988 protocol and service interface. In cases where these issues have been addressed in the 1992/3 standard, the proposed remedies are noted. Second, whilst access to an X.500 directory service is by protocols which have been standardised, the environment in which it runs can vary in many ways: hardware and network infrastructure; directory information tree structure; naming policies; access policies; data coverage and management; effort required for system management. However, new users of the Directory have no knowledge of this lack of uniformity, and often, quite reasonably, expect a fully populated Directory with all information accessible at high-speed. The paper suggests a range of approaches to help the directory user cope with this diversity: some of the recommendations require service agreements and coordination, whilst others have implications for user interface design.

The Effects of Physical Attributes of Computer Interface Design on Novice and Experienced Performance of Users with Physical Disabilities

It is well accepted that with even very simple tasks, a user's performance with a cursor control device improves substantially over some period of time before stabilizing. Although no systematic studies are available concerning how particular attributes of screen or device design affect the rate at which users learn to interact with a system, past studies with input devices have shown that the overall period of time required to learn to physically interact with a system is generally quite short. Hence the lack of attention paid to the “learning” phase with respect to physical interaction is probably justified. For users with mobility impairments, however, not only may the overall physical learning phase be significantly longer than for nondisabled users, but certain features of the interface design may require a longer learning period than others. Depending on how different “initial” performance is from “practiced” performance, systems meant for “walk up and use” or casual use may need to be designed differently to allow easy access for persons with mobility impairments. In addition, adaptive interfaces which change the physical design of features over time as a user becomes more proficient may facilitate access for individuals with impaired motor control. Twenty persons with impaired hand and arm function (as a result of spinal cord injury) performed a target acquisition task with five cursor control devices. The task required that the user select targets of different sizes and distances using both “point and click” and “drag” modes of interaction. Time and errors were recorded. The results indicate not only that some physical design attributes negatively effect performance, but that the magnitude of the effects differ for “initial” performance and “practiced” performance. In fact, in some cases attributes which had no effect once performance had asymptoted were shown to have a significant effect on novice performance. Also, some features required significantly longer periods of time for the users to become proficient at using than others. The implications for interface design are discussed.

How should Fitts' Law be applied to human-computer interaction?

The paper challenges the notion that any Fitts' Law model can be applied generally to human-computer interaction, and proposes instead that applying Fitts' Law requires knowledge of the users' sequence of movements, direction of movement, and typical movement amplitudes as well as target sizes. Two experiments examined a text selection task with sequences of controlled movements (point-click and point-drag). For the point-click sequence, a Fitts' Law model that used the diagonal across the text object in the direction of pointing (rather than the horizontal extent of the text object) as the target size provided the best fit for the pointing time data, whereas for the point-drag sequence, a Fitts' Law model that used the vertical size of the text object as the target size gave the best fit. Dragging times were fitted well by Fitts' Law models that used either the vertical or horizontal size of the terminal character in the text object. Additional results of note were that pointing in the point-click sequence was consistently faster than in the point-drag sequence, and that pointing in either sequence was consistently faster than dragging. The discussion centres around the need to define task characteristics before applying Fitts' Law to an interface design or analysis, analyses of pointing and of dragging, and implications for interface design.