## NCA Software

The NCA software is free software that can be used with the free programming language R.

**======VERSION 3.0.3 is now available======**

In *NCA 3.0.3 some minor technical changes are implemented. In the bottleneck table with percentiles, the percentiles are expressed as percentages rather than fractions. This allows for (1) interpreting the outcome values as the '100-percentage of cases that were able to reach the outcome' (e.g. the top '10 percent') and (2) interpreting the condition values as the percentage of cases that were not able to reach the threshold values of the conditions for a given outcome as 'percentage of cases that were not able to reach the required level of the condition'. Another change is that for small samples (up to N = 6), NCA’s statistical test can now be performed with all unique permutations such that the p-value is exact rather than an approximation. ** *

*A video *__explanation of the bottleneck table__* , and a video demonstration on how to produce the bottleneck table with the NCA software are available. *

A Quick Start Guide is available, and also a demonstration of conducting NCA in three steps.

A novice user without knowledge of R or NCA can install the software on the user’s computer and perform an NCA analysis within 15 minutes.

The software draws ceiling lines and produces several NCA parameters (including necessity effect size) to interpret the results.

An example is shown here.