Keywords: POP-I.B. teaching specification, POP-II.B. formal specification, POP-III.C. cognitive dimensions This paper discusses research undertaken to look at the usability of Z –a formal specification notation and TranZit –a computer editor for writing Z specifications. The cognitive dimensions framework was the usability evaluation tool chosen for this research. This study focused on how particular cognitive dimensions were relevant to novice use and understanding of the Z notation when reading and writing specifications. This was investigated firstly by completing the ‘Cognitive Dimensions questionnaire optimised for users ’ (Blackwell & Green, 2000) and subsequently by an empirical study developed for some chosen dimensions. The study backed up the choices made and brought up other issues of interest. This has led to ideas for future studies. Further studies may focus on other cognitive dimensions which were found to be important for novice use of Z; or involve trying this experimental approach on other exploratory design activities. 1.

This document is the author deposited version. You are advised to consult the publisher's version if you wish to cite from it. Published version DEARDEN, A. M. (2006). Design as conversation with digital materials. Design studies, 27 (3), 399-421. Repository use policy Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Users may download and/or print one copy of any article(s) in SHURA to facilitate their private study or for noncommercial research. You may not engage in further distribution of the material or use it for any profit-making activities or any commercial gain.