The NCA calculator can be used for a bivariate necessary condition analysis to calculate the effect size of a necessary condition. The effect size d can have values between 0 (no effect) and 1 (maximum effect). An effect size of 0 < d < 0.1 can be considered as a ‘small effect,’ 0.1 ≤ d < 0.3 as a ‘medium effect,’ 0.3 ≤ d < 0.5 as a ‘large effect,’ and d ≥ 0.5 as a ‘very large effect’.(Dul, 2016, p.30).

Prepare a CSV file where rows correspond to cases, and columns correspond to the X and Y variables.

 The NCA calculator is here

(for help click here)

An example of a bivariate necessary condition analysis is shown here.

For further analyses (multivariate necessary condition analysis, additional NCA parameters, etc.) you can use the NCA software.