noun
working hypothesis
A provisional assumption used as a starting point for research or planning, subject to revision.
この研究では、まず作業仮説を立ててから実験を始めた。
In this research, we first set up a working hypothesis and then began the experiment.
仮説 is a general hypothesis, while 作業仮説 specifically refers to a provisional, practical hypothesis used as a tool for further investigation.
Compound of 作業 (work, operation) and 仮説 (hypothesis). The term is a direct translation of the English 'working hypothesis'.