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


Good fit is indicated by values above .95.