Getting lost in an infinite design space is no solution.

Almaatouq et al. argue that an "integrative experiment design" approach can help generating cumulative empirical and theoretical knowledge. Here, we discuss the novelty of their approach and scrutinize its promises and pitfalls. We argue that setting up a "design space" may turn out to be theoretically uninformative, inefficient, and even impossible. Designing truly diagnostic experiments provides a better alternative.