A questionnaire generation process presents a first subset from a set of questions of the questionnaire and receives first answers from a user. The first answers are used to determine whether the first answers are sufficient to give definite values to conditions of first rules, wherein the first rules have conditions for providing output. When the first answers are not sufficient, the conditions of the first rules can be used to identify a second subset of the questions, wherein the second subset of questions has second answers such that a combination of the first and second answers is sufficient to give definite values to the respective conditions of the first rules, and the second subset of questions can be presented to the user.