Simon P. Davies

Knowledge restructuring and the acquisition of programming expertise

This paper explores the relationship between knowledge structure and organization and the development of expertise in a complex problem-solving task. An empirical study of skill acquisition in computer programming is reported, providing support for a model of knowledge organization that stresses the importance of knowledge restructuring processes in the development of expertise. This is contrasted with existing models which have tended to place emphasis upon schemata acquisition and generalization as the fundamental modes of learning associated with skill development. The work reported in this paper suggests that a fine-grained restructuring of individual schemata takes place during the later stages of skill development. It is argued that those mechanisms currently thought to be associated with the development of expertise may not fully account for the strategic changes and the types of error typically found in the transition between intermediate and expert problem solvers. This work has a number of implications. Firstly, it suggests important limitations of existing theories of skill acquisition. This is particularly evident in terms of the ability of such theories to account for subtle changes in the various manifestations of skilled performance that are associated with increasing expertise. Secondly, the work reported in this paper attempts to show how specific forms of training can give rise to this knowledge restructuring process. It is argued that the effects of particular forms of training are of primary importance, but these effects are often given little attention in theoretical accounts of skill acquisition. Finally, the work presented here has practical relevance in a number of applied areas including the design of intelligent tutoring systems and programming environments.

Effects of concurrent verbalization on design problem solving

Abstract A significant amount of recent research in design studies has focused on the development of tools and notations intended to support various design activities by capturing the chain of reasoning behind particular design decisions. However, in order to be considered useful it seems clear that such methods should not only be able to provide an accurate description of the design process, but must also leave the nature of that process largely unaffected. This paper presents empirical findings which challenge both of these assumptions. Experimental work is presented which suggests that concurrent verbal descriptions of a design activity may not map well onto the behaviour that such descriptions are intended to characterize. Secondly, the findings presented here suggest that having to describe the design activity may affect the design process itself. This paper suggests that design descriptions are not only mediated by cognitive limitations but also grounded in the conventions of practice surrounding design activities.

Delivering cognitive psychology to HCI: the problems of common language and of knowledge transfer

Abstract Although cognitive psychology showed much initial promise, it has failed to make significant contributions to the study of human-computer interaction, which has led to a rejection of cognitivism in favour of situated action theory. The authors accept that the critique has much to offer, but reject the outright abandoning of cognitivism. Cognitive psychology needs a common language in which to describe interaction between people and artifacts: two examples of research in progress are described, one focused on events, the other on representations and the relationship between the information display and the conceptual model. Cognitive psychology also needs a better delivery method than the traditional research paper, and the idea is proposed of a vocabulary of ‘cognitive dimensions’, terms which can be meaningfully used by non-specialists (who will recognise familiar but uncrystallised concepts) and which can be used as indexes to the professional literature. These two components form a proposal for improving the effectiveness of cognitive psychology. The paper ends with the hope that mainstream cognitive psychology will broaden its area of enquiry.

Contextualizing design: narratives and rationalization in empirical studies of software design

This paper addresses the notion that contextualization of the design process can lead to second-order accounts of design problem solving which may not adequately reflect the actual behaviour of designers. Experimental work is briefly reported indicating differences between described and actual behaviour in a software design task. We examine ways in which contextualization might affect individual cognitive behaviour and using this framework we suggest reasons why divergent perspectives of the design process might arise and continue to endure. Finally, we argue that design problem solving is host to a range of potential problems that are not typically encountered in psychological studies of other problem solving behaviours.

The structure and content of programming knowledge: Disentangling training and language effects in theories of skill development

This article reviews the extensive literature emerging from studies concerned with skill acquisition and the development of knowledge representation in programming. In particular, it focuses upon theories of program comprehension that suggest programming knowledge can be described in terms of stereotypical knowledge structures that can in some way capture programming expertise independently of the programming language used and in isolation from a programmers specific training experience. An attempt is made to demonstrate why existing views are inappropriate. On the one hand, programs are represented in terms of a variety of formal notations ranging from the quasi‐mathematical to the near textual. It is argued that different languages may lead to different forms of knowledge representation, perhaps emphasizing certain structures at the expense of others or facilitating particular strategies. On the other hand, programmers are typically taught problem‐solving techniques that suggest a strict approach to pr...

Embodying theory in intelligent tutoring systems: an evaluation of plan-based accounts of programming skill

Abstract It is clear that the way in which cognitive theories are implemented in intelligent tutoring systems will have implications for both the design and the evaluation of such systems. In this paper we discuss an important psychological theory of skill acquisition in the programming domain centred around the notion of programming plans. This theory has not only been used to account for the development of expertise in programming, but has also provided the basis for the design of a number of intelligent tutoring systems. In this paper we attempt to identify problems with this theory. In doing so we examine specific criticisms of the theory based upon recent empirical research and upon an exploration of the problems relating to the way in which the original theory has been expressed in the Bridge system. In conclusion we frame the results of this analysis in a way that might encourage a better awareness of the role of theory in the development, evolution and evaluation of intelligent tutoring systems.

From Individuals to Groups Through Artifacts: The Changing Semantics of Design in Software Development

In this chapter we chart the changing semantics of software design. Our concerns focus upon the way in which the disciplines that have traditionally informed our understanding of the design process have framed modes of discourse about design. We are interested in questions relating to the way in which these diverse disciplines may interact in order to contribute to common design theory and practice. Adopting a broadly historical perspective we have identified four specific approaches to understanding the design activity and the products of design. These approaches have been chosen in order to provide a broad historical view of the changing scope and focus within software design.

Linking Theory with ITS Implementation: Models of Programming and the Development of Programming Tutors

The way in which cognitive theories are implemented in intelligent tutoring systems has implications for the design and evaluation of such systems. In this paper we discuss a theory of skill development in programming centred around the acquisition of programming plans. We examine specific criticisms of the plan theory based upon recent empirical research into programming and upon an exploration of the problems relating to the way in which the original theory has been expressed in systems intended to support the learning process. Our contention is that the development of intelligent tutoring systems should not only be guided by theory but should also inform theory. In terms of the analysis outlined here, we present an example of how this might occur. In conclusion, we frame the results of this analysis in a way that might encourage a better awareness of the role of theory in the development and evolution of intelligent tutoring systems.