Cognitive Dimensions Analyses of Interactive Systems

Software	None
Covers	Usability of interfaces
Skills Required	Knowledge of HCI, competence with some complicated computer tool, ideally some interest in psychology
Challenge	Conceptual ???? Technical ?? Programming

Brief Description

Thomas Green has argued that information artefacts such as programming languages and word processors differ along a number of cognitive dimensions, that influence how easy they are to use for different tasks. Designing an interactive system involves making trade-offs between cognitive dimensions: improving one aspect of a system may involve making it worse on another dimension.

The cognitive dimensions framework is a good lightweight analysis tool for evaluating interactive systems and making reasoned design decisions. The cognitive dimensions of artefacts include viscosity (effort involved in making local changes), hidden dependencies (connections between components that you can't see), visibility and juxtaposability (how easily you can view components), imposed lookahead (how much the system forces you to do things in a particular order), and closeness of mapping (how closely the objects and operations used by the system are related to the objects and operations you think about in the task domain).

The project deliverable is a detailed cognitive dimensions analysis of a complex interactive system, including consideration of how the design of the system might be different, and how this would affect its place on the cognitive dimensions.

The most appropriate systems to look at are tools for creating some kind of complex product, such as programming language interactive develeopment environments, or CAD systems, or sophisticated editing tools like Photoshop.

Variants/Extensions

Compare two systems (as different as possible) to do the same job (as similar as possible) - this will make the project much stronger and more interesting.

Use more than one HCI evaluation technique. Compare the results you obtain using the different techniques - are they complementary or redundant?

Resources

See http://homepage.ntlworld.com/greenery/workStuff/Papers/introCogDims/index.html for an introductory paper explaining the cognitive dimensions idea. Alan Blackwell of the University of Cambridge maintains an archive of cognitive dimensions papers.

Back to