research methods; method of study
Refers to the systematic approach or techniques used in academic or scientific investigation.
In this paper, I will explain the research methods in detail.
When choosing a research method, you need to select one that fits your purpose.
研究手法 is a near-synonym, but 研究方法 is more common and general; 研究手法 can sound slightly more technical or specific to a particular technique.
Compound of 研究 (research) and 方法 (method).