Bookmark: E.vanderVeer.92.3
Title: Task Knowledge Structures: Psychological Basis and Integration into System Design
Section: Theoretical Issues
Author: Johnson, Hilary
Author: Johnson, Peter
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 3-26
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: A major goal of HCI is to assist software designers to construct useful and usable computer systems. One way to approach this problem is to provide software designers with information about the knowledge users utilize in performing tasks. This paper first outlines the psychological basis for our approach to task modelling, Task Knowledge Structures (TKS) and then considers how to achieve the ultimate objective in developing TKS, i.e. to integrate task models into system design by providing information about users and tasks at appropriate stages in design. To facilitate the integration of TA into system design, a survey of designers was conducted to identify where, when and how task data can be represented to aid integration into system design and the designers' requirements for tools to support task model and system design integration. The results from the survey are then summarised and the designers' requirements for TA tools are outlined, followed by a discussion as to how these requirements might be met. Finally, brief details of design specifications for the proposed tools are presented.

Bookmark: E.vanderVeer.92.27
Title: Formal Modelling Techniques in Human-Computer Interaction
Section: Theoretical Issues
Author: de Haan, G.
Author: van der Veer, G. C.
Author: van Vliet, J. C.
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 27-67
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: This paper is a theoretical contribution, elaborating the concept of models as used in Cognitive Ergonomics. A number of formal modelling techniques in human-computer interaction will be reviewed and discussed. The analysis focusses on different related concepts of formal modelling techniques in human-computer interaction. The label 'model' is used in various ways to represent the knowledge users need to operate interactive computer systems, to represent user-relevant aspects in the design of interactive systems, and to refer to methods that generate evaluative and predictive statements about usability aspects of such systems. The reasons underlying the use of formal models will be discussed. A review is presented of the most important modelling approaches, which include External-Internal Task Mapping Analysis; Action Language; Task-Action Grammar; the Goals, Operators, Methods and Selection model; Command Language Grammar and Extended Task-Action Grammar. The problems associated with applying the present formal modelling techniques are reviewed, and possibilities to solve these problems are presented. Finally, we conclude with a discussion of the future work that needs to be done, i.e., the development of a general design approach for usable systems, and the need to focus attention on the practice of applying formal modelling techniques in design.

Bookmark: E.vanderVeer.92.69
Title: Errors and Theory in Human-Computer Interaction
Section: Theoretical Issues
Author: Booth, Paul A.
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 69-96
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: The problem of human-computer interaction (HCI) is an issue of, not only matching system functionality to the needs of the user in a specific work context, but also a question of presenting an image of the system that can be easily understood. Attempts to support design in such a way so as to overcome these problems are characterized as having moved through the 'guidelines' approach of the 1970s, to an 'analytic methods' perspective in the 1980s. However, existing approaches account for only limited aspects of interaction, and areas such as the misunderstandings (errors) that users experience have received less attention. In addition, attempts to construct methods that might allow designers to analyse and understand user errors have met with only limited success. It has been suggested that the theories and constructs embodied within some of the analytic methods might be of use (although such claims have not been made by the originators of these methods). We consider the failure of a usable tool (ECM), and the limited HCI theories embodied in TAG and GOMS, to adequately account for three example errors. This failure, it is argued, suggests that the next stage is for those within the HCI field to develop broad theories of understanding and action, that can form the basis for design tools, and be communicated to designers.

Bookmark: E.vanderVeer.92.97
Title: Knowledge Retrieval and Frequency Maps
Section: Theoretical Issues
Author: Brown, Gill M.
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 97-110
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: This paper attempts to reconcile some of the explanations of expert error (i.e. slips and lapses) with some of the theory relating to the use of frequency information. Although there have previously been suggestions that novice errors may be accounted for in terms of frequency gambling, it has been assumed that experts do not use anything as crude as frequency. A study is reported that investigates the use of frequency information during learning in an everyday context. An analysis of the errors that subjects made during this study, as they learnt more about the domain, suggests that 'experts' use frequency to as large a degree as novices, The factor that may differentiate experts from novices in any domain is not just the possession of domain knowledge, but also a sophisticated frequency map of the domain. Overall, these results suggest that expert errors are just as likely to be influenced by frequency of encounter in the everyday world as novice errors.

Bookmark: E.vanderVeer.92.111
Title: Event Controllability in Counterfactual Thinking
Section: Theoretical Issues
Author: Girotto, Vittorio
Author: Legrenzi, Paulo
Author: Rizzo, Antonio
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 111-133
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: The counterfactual assessment of events, i.e. is the mental construction of alternatives to factual events, is a pervasive mental process that is quite natural for people. For example, people easily make counterfactual statements when reflecting on dramatic events ('If only I hadn't drunk alcohol the night of the car accident...'). The way in which people select the events to mutate when requested to undo a scenario outcome seems to be governed by general rules. One is that subjects tend to select exceptional (i.e. unusual or surprising) rather than normal events (Kahneman and Tversky 1982a,b; Kahneman and Miller 1986). Another is that subjects prefer to select the first rather than the subsequent events in a causal chain (Wells, Taylor and Turtle 1987). We hypothesized that events corresponding to controllable actions (i.e. voluntary decisions) by the protagonist of a scenario are more mentally mutable than events which occur in the surrounding background. In experiment 1, we manipulated the order and the controllability of four events in a scenario. Contrary to the causal order effect hypothesis, subjects preferred to change the event corresponding to a voluntary decision of the scenario actor, regardless of its relative position in the scenario. Experiment 2 showed that subjects made this choice regardless of the normal vs. exceptional status of the voluntary action event. Experiment 3 gave evidence that an unconstrained action performed by the focal actor of a story is more mutable than a constrained action performed by the same actor. The implications of these findings for the analysis of accidents involving human errors are discussed.

Bookmark: E.vanderVeer.92.137
Title: Training of Pascal Novices' Error Handling Ability
Section: Computer Programming and Program Debugging
Author: Allwood, Carl Martin
Author: Bjorhag, Carl-Gustav
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 137-150
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: The present study reports on the effects of providing novices in Pascal one hour of training in the debugging of their own programs. The training presented subjects with results from previous research on novices' debugging as well as fairly detailed instructions on how to debug a program Furthermore, the instructions included explanations of common error messages from the computer. The debugging performed by the eleven subjects who received training was compared with the debugging performed by ten control subjects who programmed on their own during the training hour. The results show that the subjects who received training debugged a significantly larger proportion of their errors compared with subjects who received no training. The results suggest that especially the semantic programming errors were easier to debug for the trained group. No differences in detailed debugging behaviour were found between the groups.

Bookmark: E.vanderVeer.92.151
Title: Models of Debugging
Section: Computer Programming and Program Debugging
Author: Gilmore, David J.
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 151-172
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: This paper proposes a view of computer program debugging, which tackles some of the simplifying short-comings of existing models. The paper begins by reviewing some of the existing models of debugging and their assumptions, before looking in more detail at one of the dominant paradigms for investigating debugging, that of predicting bug detection success. A reanalysis of the bug detection data from Gilmore and Green (1988) provides evidence that the assumptions of existing models are not valid. The important part of this result is the realisation that these assumptions have been derived from a view of debugging as fault diagnosis, rather than as a critical component of design. In conclusion, the paper describes the important features of debugging as a design activity, before outlining some predictions and implications which can be derived from the model.

Bookmark: E.vanderVeer.92.173
Title: Analogical Software Reuse: Empirical Investigations of Analogy-Based Reuse and Software Engineering Practices
Section: Computer Programming and Program Debugging
Author: Sutcliffe, Alistair
Author: Maiden, Neil
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 173-197
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: This paper presents three empirical studies of software engineering behaviour during systems analytic and analogical reuse tasks. The motivation behind these studies was to inform the design of support tools for the early stages of software development. A first study investigated inexperienced software engineers during a systems analytic task and revealed that they encountered considerable difficulties. The second and third studies investigated analogical software reuse as one means of overcoming these difficulties. The second study involved an experimental investigation of the effectiveness of specification reuse on analytic performance. Reuse proved beneficial, although it appeared to lead to mental laziness manifest as specification copying. In contrast, a third study investigated analogical specification reuse by expert software engineers, to determine how successful analogical comprehension and reuse may best be achieved. Implications of findings from all three studies for the design of support tools during software development are reported.

Bookmark: E.vanderVeer.92.201
Title: An Experimental Study of the Interpretation of Logical Operators in Database Querying
Section: Database Interrogation
Author: Essens, Peter J. M. D.
Author: McCann, Carol A.
Author: Hartevelt, Mark A.
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 201-225
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: The use of logical operators in query languages is considered to be a major source of user problems in database querying. The present study investigated whether people untrained in logic could successfully interpret logical operators; and, how errors and latencies are related to the structure of the query. In an experiment, the logical complexity of an SQL-style query formulation was varied in using AND, OR, and NOT operators in either single or combined form. The latency and error data converged to show that subjects had increasing difficulty with queries constructed with a combination of different operators. The inclusion of parentheses had a strong positive effect on task performance. Verbal protocols were used to identify sources of errors in query processing. A model of query processing was formulated and predictions of latencies and errors on the basis of processing components were tested.

Bookmark: E.vanderVeer.92.227
Title: Analysing the Deep Structure of Queries: Transfer Effect on Learning a Query Language
Section: Database Interrogation
Author: Linde, Lena
Author: Bergstrom, Monica
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 227-241
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: This experiment was designed to investigate the impact on performance, while learning a query language, of specific instructions pertaining to the 'deep-structure' of the queries. The instructions related to deep-structure comprised training in analysing queries in natural language in terms of logical constituents. The effect of such instructions was investigated for two different query languages. One was a textual and one was a 'graphic' query language. The results suggested that the usefulness of explicit training in analysing queries in terms of logical deep-structure is dependent on the semantic constraints in the query language. The textual query language, which had keywords and a syntactical template such as GET_WHERE_ EQ_ assumedly induced analysis of the query regardless of pretraining, while the graphic used in this study tended to encourage a trial-and-error approach, especially when no prior training in analysing queries was given.

Bookmark: E.vanderVeer.92.243
Title: Adapting Systems to Differences between Individuals
Section: Database Interrogation
Author: Jennings, Frances
Author: Benyon, David
Author: Murray, Dianne
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 243-256
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: Adaptive systems should be able to accommodate the preferred interface styles of different users. An experiment was conducted in order to determine whether significant differences exist between individuals performing the same task, using different interfaces. Individual users' performances on five different interfaces to a computer database system, after the initial learning stage, were compared with their scores on various cognitive and personality tests. The results suggested that two interface styles are necessary for database systems in order for them to suit a range of users: an aided-navigation interface with a constrained dialogue for low spatial ability users, and a non-aided navigation interface with a flexible dialogue for high spatial ability users. Both interfaces should minimize the amount of verbal input necessary.

Bookmark: E.vanderVeer.92.259
Title: Interference among Text-Editing Commands: Fan-Effects and the Role of System Consistency
Section: Text Editing
Author: Heydemann, Martin
Author: Hoffmann, Rudolf
Author: Schmidt, Rainer
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 259-285
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: Interference effects among several commands offered by an experimental text editor were demonstrated. The experiment involved 24 computer novices correcting texts with a computer in several working sessions. The interference effects are interpreted as 'fan-effects', similar to those studied with propositional material (Anderson 1976). During the processing of editing tasks, increased latencies for key-strokes were observed with rising degrees of fan. Two sorts of fan degrees were manipulated in the experiment. Firstly, fan-effects arise if the same features of editing tasks occur for different commands (task fan). Secondly, fan-effects also arise if the same user action (e.g. key-stroke) is required for the execution of different commands (key fan). The mapping from task features to command names was varied. Consistent editors were compared to inconsistent ones. In consistent editors the same task features were mapped to the same key-strokes for different commands, while in inconsistent editors the mapping from task features to command keys was random. For consistent editors, interference due to fan is reduced as compared to inconsistent editors. The interference effects, as well as their qualitative dependence on consistency, point to functional equivalences among interference effects as observed here and as studied previously with propositional materials.

Bookmark: E.vanderVeer.92.287
Title: On the Microstructure of Learning a Wordprocessor
Section: Text Editing
Author: Wærn, Yvonne
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 287-304
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: This paper aims at studying the microstructure of computer users' actions when learning a wordprocessing system. Latencies for different actions, i.e. identifying task, planning method, selecting command, typing argument, closing command and evaluating result, during the performance of editing tasks were registered. It was found that the learning curves for latencies for all actions except identifying task, could be fitted by a power function, with a power constant around 0.90. The fit was good and the constants similar for two different commands (delete and insert). Also for the different actions observed the power constants were similar, although the curves started at very different points, ranging from 4.31 sec to 21.72 sec. Further, a model was proposed for basic operations behind the observed actions. The model proposes a sequential procedure, where planning and recalling precede action. This model was tested against two different commands and was found valid for all data on the 2% level for the delete command and on the 8% level for the insert command. The model was also tested for individual subjects, where it was found that it was adequate for at least 80 percent of the subjects in three out of four cases tested. A closer study of the model fit suggested that the recall of a command was often performed in parallel with the planning of a method. Three subjects refuted the model by reflecting after their actions instead of before as proposed by the model.

Bookmark: E.vanderVeer.92.307
Title: The Constraint Satisfaction Approach to Design: A Psychological Investigation
Section: Graphics Design
Author: Darses, Francoise
Book: Cognitive Ergonomics: Contributions from Experimental Psychology
Editor: van der Veer, Gerrit C.
Editor: Bagnara, Sebastiano
Editor: Kempen, Gerard A. M.
Date: 1992
Pages: 307-325
City: Amsterdam
Publisher: North-Holland, Elsevier Science Publishers
Copyright: © Copyright 1992 Elsevier Science Publishers
Note: Based on papers presented at the Fifth European Conference on Cognitive Ergonomics, Urbino, Italy, September, 1991. Reprinted from the journal, Acta Psychologica, Volume 78, Numbers 1-3.
Absract: More and more CAD systems are constraint-based. This raises the question whether this view is compatible with the cognitive processes involved in design. This paper presents a first psychological assessment of the constraint satisfaction approach. An empirical study, conducted in the domain of computer network design, outlines the resuits of the comparison between constraint-directed reasoning and designers' cognitive processes. It is stressed that some of the artificial intelligence (AI) formalisms which support constraint-based systems are relevant to the characteristics of psychological behaviour. Furthermore, the concept of constraint is not sufficient to describe the mental processes of design: some additional cognitive concepts have to be developed and taken into consideration in the implementation of CAD systems.