A system of pragmatic philosophy that considers idea to be instruments that should guide our actions and their value is measured by their success WordNet 3.0 & Open English WordNet

In philosophy of science and in epistemology, instrumentalism is a methodological view that ideas are useful instruments, and that the worth of an idea is based on how effective it is in explaining and predicting natural phenomena. Wikipedia

Position in the philosophy of science Wikidata

In the philosophy of science, the view that concepts and theories are merely useful instruments whose worth is measured not by whether the concepts and theories are true or false (or correctly depict reality), but how effective they are in explaining and predicting phenomena. Wiktionary