ABSTRACT
This chapter describes an in-depth analysis of the errors made by novice programmers learning to write programs in a language called SOLO. It then analyzes the underlying causes of these errors, based upon in-depth analyses of session transcripts. The relative importance of different types of error is very hard to assess, particularly across different languages, programmer skill levels, and types of programming environment. The trap philosophy allows the user to enter nearly-correct lines of a program, and then relies on the user-interface to make sense of obvious errors. J. B. H. duBoulay looked in depth at programming errors made by school teachers learning the language LOGO. Naturally, users of interactive computing environments, especially beginners, are destined to make some mistakes. Semantic and conceptual errors can be characterized by the presence of ill-formed plans in a programmer's emerging repertoire of skills.
