Alistair G. Sutcliffe

Towards a cognitive theory of information retrieval

Abstract A framework for constructing a cognitive model of users information searching behaviour is described. The motivation for the framework is to create explanatory and predictive theories of information searching to improve the design of information retrieval (IR) systems. The framework proposes a taxonomy of components for process models of the information seeking task, information need types and knowledge sources necessary to support the task. The framework is developed into a preliminary version of a cognitive theory of information searching by the addition of strategies and correspondence rules which predict user behaviour in different task stages according to information need types, facilities provided by the IR system and knowledge held by the user. The theory is evaluated by using claims analysis based on empirical observations of users information retrieval and by a walkthrough of an IR session to investigate how well the theory can account for empirical evidence. Results show that the theory can indicate the expert strategies which should be followed in different task contexts but predictions of actual user behaviour are less accurate. The future possibilities for employing the theoretical model as a tutorial advisor for information retrieval and as an evaluation method for IR systems are reviewed. The role and potential of cognitive theories of user task-action in Information Retrieval and Human Computer Interaction are discussed.

A comparison of usability techniques for evaluating design

We report on a series of experiments designed to compare usability testing methods in a novel information retrieval interface. The purpose of this ongoing work is to investigate the problems people encounter while performing information retrieval tasks, and to assess evaluation methods by looking at the problem focus, the quality of the results and the cost effectiveness of each method. This ftrst communication compares expett evaluation using heuristics [15] with end user testing [24].

Designing claims for reuse in interactive systems design

836,066. Transistors. SIEMENS & HALSKE A.G. July 19, 1957 [July 23, 1956], No. 23011/57. Class 37. An NPN or PNP transistor consists of a thick layer 3 and relatively thin layers 4 and 5, the intermediate layer 4 being exposed for attachment of the lead 6. The thin layers are produced by gaseous diffusion, and the lower layers are exposed by masking the wanted areas of the upper layers and then etching. Lead 6 may consist of gold with 1% gallium and is alloyed to the intermediate layer. Outer leads 7, 8 are of copper and are attached to the layers by tin-lead solder 1, 2. Lead 6 may lie obliquely to the exposed face of the intermediate layer. Suitable materials for the layers are germanium, silicon or an A III B V compound.

Analysing the novice analyst: cognitive models in software engineering

Abstract Cognitive problem-solving by novice systems analysts during a requirements analysis task was investigated by protocol analysis. Protocols were collected from 13 subjects who analysed a scheduling problem. Reasoning, planning, conceptual modelling and information gathering behaviours were recorded and subjects solutions were evaluated for completeness and accuracy. The protocols showed an initial problem scoping phase followed by more detailed reasoning. Performance in analysis was not linked to any one factor although reasoning was correlated with success. Poor performance could be ascribed to failure to scope the problem, poor formation of a conceptual model of the problem domain, or insufficient testing of hypotheses. Good performance concorded with well-formed conceptual models and good reasoning/testing abilities. The implication of these results for structured systems development methods and Computer-Aided Software Engineering (CASE) tools are discussed.

Task-related information analysis

Task analysis methods have paid little attention to specification of information displays. A method is described for analysing task-related information needs linked to design of information displays. The method starts by defining users requirements with information types. These are added to the task model to specify what type of information is required during the task. The next step selects appropriate means of information delivery according to the users needs. Different information access and display paradigms, e.g. hypertext, data retrieval and display media are considered. The method is illustrated with a case study of a shipboard information system.

Designing presentation in multimedia interfaces

Current Multimedia interfaces are created primarily by intuition. Development of a method for analysis and design of Multimedia presentation interfaces is described. The study investigates task based information analysis, persistence of information, selective attention and concurrency in presentation. The method gives an agenda of issues, diagrams and techniques for specification, and guidelines for media selection and presentation scripting. Use of the method is illustrated with an example from a shipboard emergency management system.

Interacting with virtual environments: an evaluation of a model of interaction

Abstract There is a need for interface design guidance for virtual environments, in order to avoid common usability problems. To develop such guidance an understanding of user interaction is required. Theoretical models of interaction with virtual environments are proposed, which consist of stages of interaction for task/goal oriented, exploratory and reactive modes of behaviour. The models have been evaluated through user studies and results show the models to be reasonably complete in their predictions about modes and stages of interaction. Particular stages were found to be more predominant than others. The models were shown to be less accurate about the exact flow of interaction between stages. Whilst the general organisation of stages in the models remained the same, stages were often skipped and there was backtracking to previous stages. Results have been used to refine the theoretical models for use in informing interface design guidance for virtual environments.

An empirical study of attending and comprehending multimedia presentations

The paper reports two studies concerning attention to and comprehension of Multimedia presentations. The MM sequence used was taken from a commercially produced CD-ROM, ‘The Etiology of Cancer’. First, an eye tracking study of the presentation is reported. A second study was then cortductekl ml the memorisation of the materials used in the eye tracking study. The results of the studies are used to propose guidelines to improve design of MM presentations.

Object-oriented systems development: survey of structured methods

Abstract Concepts of object-oriented system programming and system design are reviewed in the light of previous research on systems development methodologies. Key principles are identified and a selection of system development methods is then judged against these principles to determine their concordance with object-oriented design. The advantages of object-oriented system development are reviewed in the light of the study of structured system development methods.

Integrating methods of human-computer interface design with structured systems development

Abstract Various methods for specification and design of the human-computer interface have been proposed but practice of such methods is not widespread. Possible reasons for this may be the lack of integration of human-computer interface design with software engineering and the specialized nature of HCI methods. A method of interface design is proposed which integrates the development of the human-computer interface with structured systems analysis and design. The method covers task and user analysis, interface specification and dialogue design. A case study of a library system is used to illustrate the method which is discussed in relation to different approaches that have been adopted for interface specification and design. It is argued that software design methods should cover all aspects of process design and the human-computer interface.