In developing the Skills Profiler, the purpose of the instrument was to measure skills, not aptitude. Several approaches where considered, including measurements of General Cognitive Ability, Complexity Indices, and Vocational Preparation Metrics. The following section details this discovery phrase and presents high-level findings. The final section examines the chosen methodology.

There are many ways to measure skill and to represent the dimensions of skill required for various careers. This section describes the different quantitative composite metrics considered for use in the Skills Profiler. This analysis also considered complexity requirements and the alternative views of how one attains the capacity to cope with the complexity level of occupational demands (as in cognitive ability versus specific vocational preparation).

General cognitive ability (g). Some researchers (e.g., Gottfredson, 1986) have used general cognitive ability (g) to represent levels of required job skill or knowledge. Measures of g can be obtained from various aptitude or ability instruments like the General Aptitude Test Battery (GATB; USDOL, 1983a). However, g is not (arguably) a direct determinant of being able to perform successfully in an occupation. It does predict (with varying efficacy) individual degrees of success in the acquisition of knowledge and skill, which are presumably more direct causes of performance. Measures of g also have the unfortunate property of emphasizing large, arguable, and sporadically irrelevant subgroup differences (Flynn, 1997).

Complexity Indices. Another possible metric is some measure of occupational complexity (where high complexity infers a lack of routine repetitive work in favor of work involving high intellectual demands and/or frequent changes in task-related requirements — often involving the synthesis or interpretation of complex data (Cain, 1980, and Hunter,1986). Complexity Indices represent a viable metric because a significant amount of incumbent data exists for extrapolation (it was the approach applied to the U.S. Employment Service validation database). However, Complexity Indices correlate strongly with cognitive ability, showing significant covariance with averaged incumbent g (the validity is lower for lower complexity jobs than for higher complexity jobs). Finally, while much data exists for extrapolating complexity indices to all the careers in the MyPlan.com/O*NET database, there is no simple method for user self-assessment – that is, there is no analog among user characteristics with which this can be matched.

Specific Vocational Preparation. The necessary level of knowledge and skill for an occupation could also be represented by the amount of occupation-specific education, training, and experience that is required to perform successfully in the occupation. Ratings of Specific Vocational Preparation (SVP) are intended to be measures of the required level of specific occupational training and experience. The definition of SVP given by The Revised Handbook for Analyzing Jobs (U.S. Department of Labor, 1991b) is “the amount of lapsed time required by a typical worker to learn the techniques, acquire the information, and develop the facility needed for average performance in a specific job-worker situation”. An applicant’s, user’s, or student’s investment in a given degree of specific vocational preparation does not assure adequate acquisition of the necessary knowledge and skills, but among various indices, SVP is arguably the most direct reflection of the time investment required.

The SVP rating has two important advantages, as compared to other metrics. First, the level of the SVP requirement for an occupation can be directly linked to the level of specific occupational education and training achieved by a person. It also can be used to describe the future level of SVP that a person might intend to achieve. Consequently, people also can ask what new occupations they should explore if they are planning to pursue certain education/training opportunities. This could be used to illustrate in a very concrete way the value of additional training. Any method used to stratify occupations should provide this illustrative capability. For present purposes, it was also a key criterion that the selected stratification method would be easily communicated as user-relevant.

Secondly, using SVP rather than g-laden requirements or “complexity” reduces the direct effects of g on the procedure for linking individuals to occupations. Although there is a significant correlation between general cognitive ability and the level of training achieved by individuals, there are many other determinants of education and training success (e.g., motivation). Stratifying occupations on SVP first would reflect these other determinants while reducing the degree to which the occupational linkage was a direct function of g.

Therefore, in keeping with the goal of measuring skills, not natural ability, the SVP rating was chosen as the underlying metric for development of the Skills Profiler. The next chapter describes the development of the test instrument, followed by a chapter on stratifying careers to match the rating system of the test instrument.