The measurement error in principal components extracted from a set of fallible measures is discussed and evaluated. It is shown that as long as one or more measures in a given set of observed variables contains error of measurement, so also does any principal component obtained from the set. The error variance in any principal component is shown…

Complete paired comparisons data was obtained by use of multiple rank order (MRO) in the context of gathering rank order preferences of grade six students, their parents, and teachers for instructional objectives. Partially balanced incomplete block designs with two associate classes were used in the MRO instruments instead of the usual balanced…

The stability of psychometric "g," the general factor of intelligence, is investigated in simulated correlation matrices and in typical empirical data from a large battery of mental tests. "G" is robust and almost invariant across methods of analysis. A reasonable strategy for estimating "g" is suggested. (SLD)