Languages which are routinely used by industry, such as Basic, FORTRAN, C, C++, etc., are often not entirely suitable for expository presentation of topics in the introductory computer science curriculum. Frequently, students entering computer science programs have already studied one of these languages and have some programming experience. Choosing a language which is better suited for expository presentation of computer science topics, such as Scheme or J, can have a leveling effect amongst students who have different preparation for college level training in computer science. Moreover, choosing a language which allows expression of powerful ideas helps give the mindset which allows students to think what might otherwise have been "unthinkable" thoughts. Such notation should foster development of formal methods in addition to the practical aspect of design, analysis and programming. An important method of exposition involves building small working models of each topic. Once built, such models provide the basis for laboratory experimentation which can involve measurements, formulation and verification of hypotheses and analysis.
Programming notation becomes a powerful tool of exposition by making an appropriate choice of language. The decision about choice of programming language should be made primarily on the basis of how well key concepts in computer science may be expressed in the language. For these reasons Scheme or J is preferable to other languages commonly used in introductory computer science courses.