The research described here examines the problems encountered by people when filling in forms. Subjects were required to complete forms on the basis of a situation sketch, while thinking aloud. From the completed forms, the observations, and the subjects' comments, conclusions could be drawn about the types of problems the subjects had encountered and about the strategies they had used. These conclusions, together with various suggestions found in the literature, provided a guideline for a thorough revision of seven forms. A test showed that, after revision, the number of forms completed unacceptably was reduced by about half.