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 calculator only works with CSV files using a comma ( , ) as delimiter, and a period ( . ) as separator. If needed, the delimiter and separator can be changed in Excel. With files that do not align with this format, the calculator will return an error message. 

 The NCA calculator is here

(for help click here)

An example of a bivariate necessary condition analysis is shown here. For further analyses (multiple NCA, additional NCA parameters, etc.) you can use the NCA software.