The Effects of Semantic Complexity on Expert and Novice Computer Program Recall and Comprehension

Three experiments were conducted to test the role that semantic knowledge plays in expert programmer ability. In Experiments 1 and 2, changing the normal semantic structure affected experts more than novices, although experts still outperformed novices. Experiment 3 showed that the experts' advantage was not due merely to their better knowledge of the keywords used in the programming languages. They were also better at searching for types of keywords. Recall and comprehension measures showed the same effects only in Experiment 1. Overall, the results suggest that the role of semantic knowledge in computer programming is more complex than has been previously thought. Merely substituting for keywords or swapping the order of lines still allows the experts to search and attend better to the functions of the program. When semantically complex functions are used, experts are at an equal disadvantage but still outperform novices.