The effects of various error messages and error types on program debugging time.

Using the Shneiderrnan model, programs were bugged with three classes of errors and then flagged with five classes of error messages both to test the the Shneiderman theory and to attempt to develop more useful messages for programmers. Forty subjects, all of whom passed a general selection quiz on the programming language BASIC, participated in the study. Each subject saw three versions of a BASIC statistics program listing, the versions represented the three different types of errors and all shared a common sort of error message. The error types strongly affected the time subjects required to find the bug in the printed listing and correct it. As predicted by the theory, the syntax error was found most quickly. However, the speed at which the flow error and misuse error were detected was reversed from the order predicted by the theory. Using the scores on the BASIC quiz as a covariate, the error messages were found to affect the time to debug a listing with knowing which line caused the error reducing the time most but having a greater effect on the syntax error over the flow error