The sampling plan was designed to (1) target groups of users most likely to use the Career Personality Test upon its completion, and (2) sufficiently supply “anchor data” for the subsequent career profiling phase of research.

Participants and Design. 1,242 individuals from across the U.S. participated in the main study. 68% of respondents were in careers. The remaining respondents were students (13% in high school and 19% in college). These participants were administered the final form of the Career Personality Test comprising 60 questions. A small subset of the respondents also participated in the test-retest portion of the study, where they were administered the same instrument on two separate occasions, with approximately one month elapsing between the two administrations.

There are several ways to assess the reliability of measurement, depending on the type of consistency with which one is most concerned, including internal consistency and test-retest reliability. The following subsections will highlight the evidence gathered on the Career Personality Test that related to each of these two types of reliability.

Internal Consistency. This type of reliability is used to determine whether different questions, which are measuring the same subject on the same scale, have highly related results. For example, if a test included 10 items on math ability and 10 items on reading ability, one would expect to see higher interrelationships within the set of 10 math ability items and within the set of 10 reading ability items than between items from the two different sets. Thus, internal consistency reliability is important for the Career Personality Test because one would expect high internal consistency among the questions that comprised each of the four scales.

The instrument did, in fact, exhibit very high internal consistency estimates across all four scales (coefficient alphas ranging from .86 to .95), indicating that each of the scales “hangs together” well. Thus, it could be said that on the basis on internal consistency the instrument has very high reliability.

Test-Retest Reliability. This type of reliability refers to the consistency of results when the same individual is administered on the same test at two points in time. This information is obtained by looking at the degree of relationship (i.e., correlation) between an examinee’s two scores. Estimates of test-retest reliability are particularly useful if the characteristic being measured is not expected to change over time between the two measurement periods. Given that the personality characteristics are considered to be relatively stable characteristics, one would expect that the participants’ responses would be very stable across a short period of time.

The instrument did, in fact, exhibit very high test-retest reliability (ranging from .81 to .92), providing evidence that clients’ scores are likely to be similar if the instrument is taken more than once within a short period of time.

The term validity, as used here, refers to whether or not an instrument functions as it was intended to function. The Career Personality Test was designed to measure personality preferences on four scales according the archetypes and typology pioneered by Carl Jung in his landmark book, Personality Types. The Career Personality Test is intended to measure personality according to these constructs in much the same way as the MBTI and other modern personality assessment instruments.

Before starting the test, respondents in the study were asked if they had ever taken the MBTI (or other similar Jungian personality test), and if they had, could they remember their composite personality type (e.g. “ESFP”). A small subset of the participants in this study reported having previously taken a Jungian personality test. 65% were able to recall their reported personality type.

On the basis of this small sample, a preliminary validity analysis indicated that the type correlations of the summary composite scores were fairly high at an average of .77 (ranging from 0.0 to 1.0). This indicates that, at least to the extent of recall in this sample, the Career Personality Test converges well with other popular measures of personality such as the MBTI. Further evidence of validity should be forthcoming in the next year.