Page 63 contains a footnote where I give the formula for the phi coefficient. Unfortunately, the denominator mixes up products and sums, so is incorrect. The correct formula should be:
phi = ad - bc / SQRT [(a + b) x (c + d) x (a + c) x (b + d)]
I'm grateful to John van den Bercken for pointing this out.
David
Showing posts with label phi coefficient. Show all posts
Showing posts with label phi coefficient. Show all posts
Saturday, 17 October 2009
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