The power of the procedure of W. Stout to detect deviations from essential unidimensionality in two-dimensional data was investigated for minor, moderate, and large deviations from unidimensionality using criteria for deviations from unidimensionality based on prior research. Test lengths of 20 and 40 items and sample sizes of 700 and 1,500 were…

The performance of the following four methodologies for assessing unidimensionality was examined: (1) DIMTEST; (2) the approach of P. W. Holland and P. R. Rosenbaum; (3) linear factor analysis; and (4) non-linear factor analysis. Each method is examined and compared with other methods using simulated data sets and real data sets. Seven data sets,…

The general intelligence factor (g) was investigated using 170 university students across three batteries of ability measures: (1) a short-term memory battery; (2) the Multidimensional Aptitude Battery; and (3) a reaction time battery. Results support the notion of g and suggest short-term memory as an essential aspect of intelligence. (SLD)