The third part is about the research topic and methods, including limiting concepts, the research topic as well as research methods.

第三部分是研究问题与研究方法，包括概念界定、研究问题和研究方法。

youdao

Let me be clear, applicability is about limiting the effort the reader needs to make to translate the concepts conveyed in the book into applying them to his own work setting.

让我说得更清楚一点，适用性指的是让读者将书中的概念应用于实际操作所要花费的精力降至最低。

youdao