描述性研究法一共分为三类：观察法，案例分析法以及调研法。
There are three main types of descriptive methods: observational methods, case-study methods and survey methods.
因为很难再有一种更具有描述性的观察，而它也确实如描述的那样说了。
There could hardly be a more descriptive observation, and it means exactly what is says.
观察法和专题讨论法适用于探索性调研，问卷调查法适用于描述性调研，而实验法适用于因果性调研。
While observation and focus groups are best suited for exploratory research, surveys are best suited for descriptive research and experiment for causal research.
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