Tests for independence between two sets of Number - Multi (see Variable Sets) questions, containing \(p\) and \(q\) variables respectively. The test statistic is:
\[\begin{align} V = -((n - 1.5) - (p + q) / 2.0)\sum^m_{i=1} \log(1 - r^2_i) \end{align}\]
where:
\(n\) is the is the Effective Sample Size (see Weights, Effective Sample Size and Design Effects),
\(p \approx \Pr(\chi^2_{pq} \ge \Lambda)\)