This paper provides a theoretical review of self-rated competences questionnaires. This topic is influenced by the ongoing world-wide reform of higher education, which has led to a focus on the learner outcomes of higher education. Consequently, questionnaires on self-rated competences have increasingly been employed. However, self-ratings are often criticised for their lack of validity. Our intention is to outline some principles of good questionnaire design and to use these principles to contrast questionnaires on self-rated competences. We begin with an overview of research about questionnaire design. Then we introduce seven questionnaires and portray them in terms of their design characteristics. A comparison reveals some significant points: biographical data need to be handled more carefully, and there is an overuse of vague and abstract language. On the positive side, all of the questionnaires that were examined provide reliable sub-scales covering important facets of competences. (Contains 1 table.)