Static vs. dynamic type systems: an empirical study about the relationship between type casts and development time

Static type systems are essential in computer science. However, there is hardly any knowledge about the impact of type systems on the resulting piece of software. While there are authors that state that static types increase the development speed, other authors argue the other way around. A previous experiment suggests that there are multiple factors that play a role for a comparison of statically and dynamically typed language. As a follow-up, this paper presents an empirical study with 21 subjects that compares programming tasks performed in Java and Groovy - programming tasks where the number of expected type casts vary in the statically typed language. The result of the study is, that the dynamically typed group solved the complete programming tasks significantly faster for most tasks - but that for larger tasks with a higher number of type casts no significant difference could be found.