Seven deadly sins of introductory programming language design

Discusses seven undesirable features that are common to many programming languages used to teach first-time programmers: (1) less is more; (2) more is more; (3) grammatical traps; (4) hardware dependence; (5) backwards compatibility; (6) excessive cleverness; and (7) violation of expectations. We illustrate typical pedagogical difficulties which stem from these features, with examples drawn from the programming languages ABC, Ada, C, C++, Eiffel, Haskell, LISP, Modula 3, Pascal, Prolog, Scheme and Turing. We propose seven language design (or selection) principles which may reduce the incidence of such undesirable features: (1) start where the novice is; (2) differentiate semantics with syntax; (3) make the syntax readable and consistent; (4) provide a small and orthogonal set of features; (5) be especially careful with I/O; (6) provide better error diagnosis; and (7) choose a suitable level of abstraction.