David Ackermann

The role of mental models in programming: from experiment to requirements for an interactive system

We will outline some basic psychological aspects in the process of programming and discuss them in a first case study showing different developments of mental models. We will exemplify the role of visualization for the support of mental models, working memory and knowledge structure and consequent thinking. In a second case study we will demonstrate the possibility of graphical representation of command language with predefined syntax but semantic flexibility.

INDIVIDUAL DIFFERENCES IN HUMAN—COMPUTER—INTERACTION: HOW CAN WE MEASURE IF THE DIALOG GRAMMAR FITS THE USER'S NEEDS?

The human-computer interaction for two calculator tasks and one drawing task was investigated. It was found that individual differences exist and have to be considered in system design. Methods that indicate individual preferences and difficulties with task structuring and single commands are presented. Results of one task domain turned out not to be transferable to other domains. This questions the generality of results in human—computer interaction.

A context-oriented approach for decision support

In this paper we address the question, how to design a DSS-generator, such that the effort for building a specific DSS is small but at the same time the user-interface reflects the individual semantic structuring of the scope of actions. A conceptual answer to the question raised above is proposed in the rest of the paper. Through the a-priori specification of a context underlying a DSS-generator a mental frame is defined for 1. confining the problem-domain, 2. integrating harmonically the various components of a DSS-generator, 3. defining, representing and manipulating objects, relations and operations compatible to the users mental processes and hence 4. facilitating the design of specific DSS reflecting the individual scope of actions.

Visualization of program structures: support concepts and implementation

The programming process is a highly demanding intellectual activity requiring visual support at all stages of development. In this paper, we discuss the implications for the user-interface of software development tools and describe how Macpeth, a program editor for educational purposes, meets these requirements.