Dan Diaper

World Wide Web working whilst ignoring graphics: good news for web page designers

Abstract Many web pages are made up of blocks of text with surrounding graphics. In some cases these graphics are animated in a variety of different ways. A common task of web users is to search the text on a web page for some information of interest and, often, this is what such pages’ designers expect. Where information extraction from text is likely to be the primary concern of both web users and designers, then it is useful to know if typical, current examples of surrounding graphics, animated or static, distract people from their primary information extraction task. An experiment using realistic web pages supports the view that experienced web users are not distracted by surrounding graphics. This is good news for web page designers because such graphics are often considered highly desirable, and are sometimes commercially essential as paid advertising. Data on the time it takes to search for information on web pages and their perceived complexity are also presented.

Scenarios and task analysis

Abstract A Critical Review of Carrolls book on scenario-based design is offered [Making Use: Scenario-Based Design of Human–Computer Interactions (2000)]. Carroll characterises scenarios as ‘stories about use’. The paper demonstrates that Carrolls proposals about scenarios and their use in software engineering can be fitted into the broader framework of task analysis in Human–Computer Interaction.

Task analysis and systems analysis for software development

Abstract The paper offers a commentary on Benyon (1992). It questions the absence of a role for task analysis in the early stages of system development and attempts to refute many of Benyons assumptions and criticisms concerning task analysis methods, at least by showing that his criticisms do not apply to all of them. The commentary also questions Benyons systems analysis model for software development and suggests that it is unrealistic.

Two Falls out of Three in the Automated Accessibility Assessment of World Wide Web Sites: A-Prompt vs. Bobby

The results of comparing two World Wide Web accessibility assessment tools, Bobby and A-Prompt, is reported. The two tools were applied to a sample of 32 UK university Web site home and search pages. Relating the tools’ outputs to the Web Content Accessibility Guidelines, A-Prompt found all the guideline compliance failures that Bobby did at both priority levels 1 and 3 and some more that Bobby did not detect. At priority level 2 there was no agreement between the tools as to the compliance failures they detected.

Software requirements validation via task analysis

As a baseline for software development, a correct and complete requirements definition is one foundation of software quality. Previously, a novel approach to static testing of software requirements was proposed in which requirements definitions are tested on a set of task scenarios by examining software behaviour in each scenario described by an activity list. Such descriptions of software behaviour can be generated automatically from requirements models. This paper investigates various testing methods for selecting test scenarios. Data flow, state transition and entity testing methods are studied. A variety of test adequacy criteria and their combinations are formally defined and the subsume relations between the criteria are proved. Empirical studies of the testing methods and the construction of a prototype testing tool are reported.

Task analysis for knowledge descriptions (TAKD): A requiem for a method

The primary purpose of this paper is to stop people using the Task Analysis for Knowledge Descriptions (TAKD) method. Secondly, by describing the history of TAKDs development and demise over nearly two decades, it allows lessons to be learned that may be relevant to existing methods and to those being developed. Both the adequacy of TAKD as a product and its delivery to HCI and software engineering practitioners is examined, and TAKDs failure on both these aspects is described. The value of developing software tools to support analysts is emphasised and illustrated by the development of the LUTAKD toolkit. It is argued that it is essential for task analysis to be able to model software if it is to be used as part of a software requirements and design specification process.

The discipline of HCI

The subtitle of the journal interacting with Computers: the Interdisciplinary Iournal of Human-Computer Znteraction was chosen because Human-Computer Interaction (HCI) is an endeavour that involves many disciplines. It is debatable whether HCI is a discipline. What should not be debatable is that the ‘I’ in ‘HCI’ stands for ‘interaction’ and not for ‘interface’. The latter assumes that solutions to problems in HCI always involve the interface between a computer and its operator. However, unless ‘interface’ is defined too broadly to be useful, there are solutions in HCI that do not involve changing the interface at all. For example, some problems may be solved by providing training, or by changing the operators’ tasks or the practices of their organisation. One of the few apparent agreements in HCI is that it enjoys input from a variety of different disciplines. It has been described as pluralistic (Norman and Draper, 1986) and multidisciplinary (Baecker and Buxton, 1987). However, these terms could be interpreted as implying that HCI is not a discipline, but an area to which other, true disciplines, contribute. Norman and Draper, for example, state, ‘We are prepared to take on board any discipline, any approach that helps.’ This editorial argues that there is a discipline of HCI, albeit an engineering, rather than a scientific, one. If HCI is a discipline then it should possess at least a set of common goals, if not common axioms. This editorial proposes that the goals of HCI are: ‘to develop or improve the safety, utility, effectiveness, efficiency, and usability of systems that include computers’. The term ‘system’ here derives from systems theory and HCI systems are not computer systems, nor only operator-computer systems, but need to be represented as richer, more complex systems. This led Diaper (1986) to suggest that HCI safety issues, for example, need to encompass not only the computer system and its individual users, but also colleagues who do not use the computer, the organisation that owns the computer, and also those less immediately involved including households, other organisations, classes within society and society itself, both national and global. A concern with systems of this breadth clearly requires an eclectic approach involving many disciplines. However, these goals often conflict. For example, a commonly used command might, on the grounds of efficiency, be implemented so as to require a minimum of keystrokes. This can have serious consequences if a keystroke error is

Collaborative document annotation using electronic mail

The primary purpose of this paper is to describe an approach to software development, the small scale approach, that is particularly appropriate for groupware that has a target user population that is truly global. Many of the reasons why the small scale approach is appropriate are described.To support the papers primary purpose, the domain of document annotation in collaborative writing is used to illustrate the requirements of such global groupware. A simulation shows how the proposed software might be used by individuals and how annotations might be automatically combined. The requirements analysis from this leads to a high level program design which is implemented, for illustration, as a PERL program.

Do-It-Yourself Electronic Lectures in Microsoft Powerpoint

Do-It-Yourself Electronic Lectures (DIYELs) are intended to allow academics to easily and effeciently convert lecture material in Microsoft Powerpoint into an e-lecture that can be delivered to students on their own computer. Our current design of DIYELs is described, and how these can be created. Example tricks when using Powerpoint are provided to illustrate how to increase the ease and efficiency of DIYEL production. The potential, global market for e-lectures is discussed.

Hardening Soft Systems Conceptual Modelling

There are many ways in which Soft Systems Methodology (SSM) is soft to advantage. While ‘bubble and arrow’ diagrams are a popular style of depicting SSM conceptual models, SSM explicitly accommodates alternative systems modelling approaches, without affecting its other desirable soft properties. Two, harder notations and methods to the ‘bubble and arrow’ style of conceptual modelling are proposed. First, if a similar graphical notation to it is to be used, then SSM conceptual analysts should profit from adopting the more rigorous notation and methods of software engineering’s Data Flow Diagram (DFD) analyses. Second, the formal method Simplified Set Theory for Systems Modelling (SST4SM) has been designed so that it requires little mathematical knowledge to understand and use. The SST4SM algebraic expressions in tabular systems models are claimed to be easy to construct and reason with, even by the mathematically challenged. The use of the SST4SM method is claimed to lead to systems models that are better in many ways from those likely to arise from the ‘bubble and arrow’ type approaches. Furthermore, the size of an SST4SM system model, which can be grown iteratively, is not as limited as graphically based conceptual models.