skill variables were originally organized into a smaller number of higher-order aggregates of those skills, based on the available theoretical and empirical evidence. These higher-level organizations were evaluated using the incumbent and analyst data. This was accomplished by computing correlations among the descriptors within each type (e.g., skills), factor analyzing the correlation matrices, and comparing the results to the original organizations of descriptors. The resulting reorganizations of descriptors were called "rational/empirical models" since they combined rational and empirical analyses to arrive at the structures.
The alternative rational/empirical models based on analyst data, not too surprisingly, appeared to describe the underlying structure of the analyst or transitional database better than the original content models for the ability, skill, and generalized work activity descriptors, respectively. Thus, these hierarchical structures are probably most appropriate for many uses of the transitional analyst dataset, especially for purposes of developing occupational scores for higher-level aggregates of descriptors. Regarding these aggregates, the second-order categories (for example, there are 16 second-order skill categories) were thought to be more appropriate for the development of aggregates than are the highest-order categories (for example, there are 6 highest-order skill categories). These latter categories are extremely broad, and aggregates formed at this level would lose too much information for most purposes. Several methods of combining descriptor scores into the higher level scores were investigated.
It is well known that professional and legal guidelines stipulate that the use of selection tests should be based on job analysis information. Consequently, the use of information obtained from job analyses is a critical element for identifying and establishing requirements for jobs, and the identification of important work behaviors and the employee characteristics that underlie those behaviors leads to the choice of appropriate selection tests. Research was conducted to demonstrate the applicability of the