Noncentrality-Based Indices of Fit - McDonald's Index of Noncentrality
McDonald proposed this index of noncentrality in a 1989 article in the Journal of Classification. The index represents one approach to transforming the population noncentrality index F* into the range from 0 to 1. The index does not compensate for model parsimony, and the rationale for the exponential transformation it uses is primarily pragmatic.
The index may be expressed as
e(-F*/2)
Good fit is indicated by values above .95.