Yvonne Waern

On the interaction between system and user characteristics

Abstract Abstract. The development of a representational framework, based on Morans Command Language Grammar, for constructing adaptive computer systems is the main topic of this paper. A model of the user interface is developed of which two aspects are discussed: the mental model in the mind of the user and the perceptual model on the side of the machine. Cognitive style and personality factors are considered in their relation to the development of the mental model. The concept of metacommunication is analysed and discussed on all levels of Morans CLG.

Learning computerized tasks as related to prior task knowledge

Abstract This paper presents a theoretical analysis of the relationships between the requirements of a computerized task and peoples knowledge of this task outside the computer system. The analysis is based on the goals to be reached, the methods which may be used, and the conditions which must be satisfied for each method to be used, with or without the computer system. It is suggested that it will be most difficult to learn a computerized task when new methods are related to old goals and/or when old methods require new conditions to be satisfied. Emperical observations supporting analyses of different tasks are presented. The empirical data reveal difficulties which are not predicted by the theoretical analyses, and it is concluded that a good prediction of the ease with which a new system is learnt can only result from a combination of theoretical analyses and empirical observations of users working with the system.

On the implications of user variability in open systems An overview of the little we know and of the lot we have to find out

Abstract As the use of computers increases, the cost of educating computer users rises. Therefore the need for extensive education of users should be avoided as much as possible. Instead computer systems should be adapted to the requirements and characteristics of computer users. Hereby the need to identify user characteristics arises. The less computer educated the users, the more their requirements of the systems will differ. Where user characteristics are difficult to change, it will be worthwhile to attend to user differences in the design of systems. The implications of user differences may vary depending upon the type of task to be performed. The present paper presents an analysis of different user characteristics and their possible interactions with different task requirements. Hereby some recommendations regarding the need to educate users or adapt systems to the user were derived.

Communication knowledge for knowledge communication

Abstract Knowledge systems can be regarded as agents communicating between domain experts and end users. We emphasize the concept of “communication knowledge”, distinct from the domain knowledge. Three aspects of communication knowledge are identified and research related to them presented. These are domain-related knowledge, discourse knowledge and mediating knowledge. This frame of reference is applied in the contexts of knowledge acquisition, user interface management in knowledge systems, text generation in expert critiquing systems and tutoring systems. We discuss the implications of the proposed framework in terms of implemented systems and finally suggest a future research agenda emanating from the analyses.

Reading text from visual display units (VDUs)

Abstract This article presents an analysis of the task facing people, who have to read text from VDUs. Psychological research related to different aspects of this task is reviewed. First, situational factors are considered. It is suggested that the VDU situation may lead to fatigue and stress, which may decrease performance. Then a task analysis is performed, where potential difficulties and advantages of the VDU presentation are pointed out. Psychological investigations of text processing are then reviewed, with particular consideration of research methodology and text processing theory. Finally, some conclusions for planning research in this area are presented.

Office Automation and Users' Need for Support

We investigated a recently introduced office automation system at Swedish Telecom. In a first study, where 275 users answered an inventory, the users indicated that they found the system useful, b ...

Human factors in electronic mail system design

The current paper analyses how human factors aspects and system design aspects may co-operate in the design of a particular application, i.e. electronic mail systems. A review of research on the experience of electronic mail systems is presented, as well as a pilot study covering the experience of mail systems in different user groups. The users were found to differ mainly in terms of the tasks they performed and wanted to perform. It is therefore suggested that a task analysis is essential in system design. Current practice on task analysis is presented, which shows that a more detailed task analysis is needed to be useful. In order to achieve flexibility, the subtasks found should be designed in a modular way. Here the system designer will need different supports. To facilitate co-operation between end-users and system designers some kind of communication support is also suggested.

On search in an incomplete database

Abstract The purpose of this investigation is to determine the psychological factors which are important for the efficient use of information from an incomplete database. Ten psychology students were instructed to answer a question by searching for information in a database. The question was not directly answerable but required the subjects to make inferences from the information retrieved. The following differences were found between the most and the least efficient subjects: the more efficient subjects started by obtaining an overview of the alternative search words available. They used the information obtained both to find possible answers and to exclude impossible ones. The more efficient subjects used prior knowledge schemata to make inferences, which yielded fewer possible candidates than the prior knowledge schemata used by the less efficient subjects. The less efficient subjects became more confused by the different possibilities, forgot information retrieved and repeated searches. It was concluded than an efficient search in an incomplete database requires that people have an overview of the alternatives offered. It also requires that one should make inferences from the information obtained in order to form possible hypotheses and to reject impossible alternatives.

A MODEL FOR MULTIDIMENSIONAL SIMILARITY

A multiplicative model is proposed for the similarity between stimuli varying in easily discerned dimensions. According to this model, the multidimensional similarity estimate equals a product, weighted by exponents, of the unidimensional estimates. The multiplicative model, together with two alternative ones, a vector model and an additive model, are tested in two experiments where the stimuli are varied in two dimensions. The multiplicative model seems to describe the empirical data most closely.

How do You Fill in This xxx? On Some Interpretation Processes

This report aims at describing how readers reason as they search and interpret a missing word in a given text. Each of thirty-seven psychology students were instructed to think aloud while they attempted to interpret a missing word in short texts. The thinking-aloud protocols indicated that the protocols differed, depending upon how the text was encoded. The common thought operations consisted in 1) locating schemata from prior knowledge, 2) suggesting an interpretation, within the restrictions of the schemata and encoding, and 3) checking. Different strategies were used to decide which operation to use and when.