Meta-Evaluating Quantitative Internal Evaluation: A Practical Approach for Developers

Within the field of Computational Creativity, evaluation is one of the most important and more difficult tasks. Sometimes evaluation is part of the creative systems themselves, becoming an internal evaluation. Being a module of a creative system, it is useful to evaluate how effective this internal evaluation is. In this paper, we propose a procedure for the (meta-) evaluation of internal evaluation modules, that allows for incremental development of both the evaluation module and the creative system, which are considered fully independent of each other. The procedure works by statistically comparing the evaluation of the average output of the generation system with the best results from the same, to see if the evaluation procedure can statistically distinguish the two. We then show how to apply the procedure giving one example evaluating a module we designed to assess structural coherence in generated folk music.