Development milestones towards a tool for working with guidelines Jean Vanderdonckt * Université catholique de Louvain, Institut d'Administration et de Gestion, Place des Doyens, 1 - B-1348 Louvain-la-Neuve, Belgium Abstract Several tools for working with guidelines already exist, both as commercial products as well as within research and development. Since these tools frequently manipulate guidelines during many de- velopment steps of a user interface of an interactive application, they can overthrow any approach fol- lowed to develop this application. They also raise the fundamental question of to what extent can we trust these tools. To answer this question, we introduce five development milestones through which we must pass to produce a high quality tool for working with guidelines: 1. an initial unstructured but comprehensive set of guidelines is formed by collecting, gathering, merging, compiling guidelines from all available world-wide ergonomic sources; 2. the initial set is sorted and classified within a single organising framework; 3. a methodology, paying particular attention to finding and applying relevant guidelines is devel- oped for grounding interactive applications on the organised set of guidelines; 4. the structured guidelines and the supporting methodology are given computational representa- tions for manipulation by computer-based tools; 5. the methodology developed in 3. is further modified to optimise the effectiveness of computer- assisted user interface design . In this paper, we define these milestones and their associated goals, specify a general procedure and discuss some problems raised at each milestone. We then deliver an analytic synthesis of various expe- riences acquired to solve these problems and we discuss the validity of these experiences from the point of view of completeness, consistency and correctness. From these experiences, we finally draw some lessons useful for any future usage and development of a tool for working with guidelines. © 1999 Elsevier Science B.V. Keywords: Computer-Aided Design of User Interfaces; Development methodology; Ergonomic algo- rithm; Evaluation; Guidelines; Human-computer interaction; Interactive application; Software devel- opment methodologies; Software engineering; Software ergonomics; Standard; Style guide; Tools for working with guidelines; Usability; User interface. 1. Introduction Ensuring the ergonomic quality of user interfaces (UIs) has become a major concern when devel- oping interactive applications for over a decade. To characterise this quality, utility and usability are often distinguished. Utility translates the appropriateness of a UI with respect to the functional goals of an interactive application ; in this way, it remains user independent. In contrast, usability relates to the appropriateness of this UI with respect to the operational user’s goals ; it therefore heavily depends on the user. The UI of a word processor could be considered as useful in providing a facility for com- puter-aided creation of a table of contents of a given document ; the usability of this UI will depend on the easiness with which a user will be able to carry out this task, without being blocked by an error, but being supported to fix it. The suitability of interactive applications which are functionally rich (thus, useful), but operation- ally poor (thus, unusable) still gives rise to dilemmas: intensive, experienced users tend to prefer a useful interactive application, even when it is not usable rather than a usable interactive application which lacks utility; casual or novice users tend to reject an interactive application as soon as it is unusable, even if it is very useful; they prefer an application which is a little useful, but usable. * Corresponding author. Editor-in chief of this special issue on “Tools for Working with Guidelines”; Tel: +32- 10/47.85.25; Fax: +32-10/47.83.24; e-mail: vanderdoncktj@acm.org, vanderdonckt@qant.ucl.ac.be; WWW: http://www.qant.ucl.ac.be/membres/jv/jv.html