Science is praxis relevant to the extent that it guides goal-directed action by telling us how to act in order to achieve the goals. Investigations aiming at high praxis relevance are performed in various disciplines under names such as clinical trials, evaluation research, intervention research and social experiments. In this contribution, the notion of (direct) praxis relevance is delineated, and it is distinguished from related properties of science such as those of being applied and being practically useful in a wider (...) sense. Recommendations for the achievement of praxis relevance are offered in the form of five principles: the prerogative of direct experiments, minimized theory-induced uncertainty, multiple approximations, causal chain decomposition and successive improvements. (shrink)