Any system designed for people to use should be easy to learn and remember, effective, and pleasant to use. Over the years there has been a considerable increase in designing interfaces that score highly on these issues. This experience has been documented in a number of guidelines for constructing good human-computer interfaces [5, lo]. Following these guidelines is commonly considered a necessary but insufficient condition for constructing good human-computer interfaces. Most often, following such guidelines during the design phase imposes little extra effort on a development project. Guideline reports, however, are often lengthy. Documents of more i.han 400 pages are not uncommon. The mere size of a guideline report often means that it is not consulted during design or design review simply because the work of locating relevant guidelines is not considered worth the effort. This article describes a survey that we undertook to investigate whether industrial data processing professionals would be able to recognize serious interface problems in simple but realistic dialogues. Seventyseven designers and programmers from industry and academia participated. Fifty-one were from industry, 10 were teachers or students from universities or high schools, and 16 had occupations that were not specified. Many of them were designers and programmers of administrative systems-the people who design, write, and maintain our daily programs. This article consists of four parts. We first present the survey and a number of conclusions from it. The second part of the article presents the exercise used in the survey-a dialogue that we asked the participants to evaluate as expressed in Appendix 1. The third part contains our annotated solution as shown in Appendix 2 and a suggestion for an improved design as characterized in Appendix 3.