An outline history of the programming language conditional is given, followed by a description of some experiments to find which form of conditional is easier to use. Experiments on whether improved teaching methods and structure aids can help users of programming languages with conditional GOTOs to write and debug their programs more easily are then described. It is concluded that behavioural experiments on programming languages can be useful to the language designer, and that the teaching of desirable program structure, rather than just programming language structure, is useful to the student.