Part II. Application

Part II of the book demonstrates how to apply the principles of NCA in an empirical study, whether in research or in a practice setting. The primary aim of an NCA study is to identify conditions \(X\) (e.g., actionable factors) that enable or constrain an outcome \(Y\), which may be either desirable (e.g., performance) or undesirable (e.g., disease). Identifying necessary conditions rather than average contributing factors provides novel insights in research and opens new possibilities for effective action in practice. Once the specific goal of the empirical study is defined, the NCA method involves formulating a formal necessity hypothesis (\(X\) is necessary for \(Y\)) and testing this hypothesis using empirical data.

After establishing the goal, the application of NCA consists of four stages:

  1. Formulate the necessary condition hypothesis.
  2. Collect the data.
  3. Analyze the data.
  4. Report the results.

The first chapter (Chapter 7) discusses the steps that are needed for developing a formal necessity hypothesis. The next chapter (Chapter 8) discusses data collection in terms of the selection of study design (observational study, longitudinal study, case study, experimental study), sampling and selection of cases, measurement (getting scores for \(X\) and \(Y\)), and the dataset. This is followed by Chapter 9, which discusses NCA’s data analysis. Chapter 10 provides guidance on reporting an NCA study. Chapter 11 illustrates the use of NCA in multimethod studies (NCA with regression and NCA with QCA) and Chapter 12 describes the application of NCA in practice. This part ends with a summary and personal reflections.