This paper describes a classification scheme that can be used to investigate the characteristics of introductory programming examinations. The scheme itself is described and its categories explained. We describe in detail the process of determining the level of agreement among classifiers, that is, the inter-rater reliability of the scheme, and we report the results of applying the classification scheme to 20 introductory programming examinations. We find that introductory programming examinations vary greatly in the coverage of topics, question styles, skill required to answer questions and the level of difficulty of questions. This study is part of a project that aims to investigate the nature and composition of formal examination instruments used in the summative assessment of introductory programming students, and the pedagogical intentions of the educators who construct these instruments