Monday, February 26, 2007

Personality testing basics: Part 2


There continues to be great interest in using personality tests for personnel selection. In Part 1 of this series I reviewed some of the major modern research on personality testing. In this post I will review some of the major commercial personality tests that can be used for selection.

This is by no means an exhaustive list, but these tests have been around for a while, have generally withstood professional scrutiny, and are used by many organizations as part of their hiring process. While not all of them are strict measures of the Big 5, all are based or strongly related to those factors. I mentioned that while not everyone agrees that the Big 5 is the best way to describe normal personality, it does have considerable support.

Below I have provided a brief description of these tests along with any evaluative comments (if I had them) from the Mental Measurements Yearbook (MMY), one of the few objective reviewers of commercial tests. All can be administered via computer or paper-and-pencil and vary somewhat in price (approximately $10-30 per test--contact publisher for details).

The Tests

1. Hogan Personality Inventory (HPI) - The HPI, created by the well-known Dr. Robert Hogan, is based on the Big 5 but actually has seven scales--Adjustment, Ambition, Sociability, Interpersonal Sensitivity, Prudence, Inquisitive, Learning Approach (note that several names have changes in the last few years). The HPI consists of 206 true/false items that according to Hogan Assessment Systems are written at a 4th grade reading level and take 15-20 minutes to complete.

MMY (1998) quotes on HPI:
"...[the HPI] appears to be a theoretically sound, carefully conceptualized, and well-validated instrument offering practical utility for organizations."
"...[the HPI] is a valid and reliable test..that is recommended for use as part of a battery in vocational and personnel selection settings.
"

2. 16PF - The 16PF is published by IPAT and is based on the research of Dr. Raymond Cattell, one of the most famous psychologists who (among other things) is credited with theorizing the existence of fluid and crystallized intelligence. The 16PF measures sixteen "primary factors" as well as the Big 5, contains 185 three-choice items, and IPAT states it is written at a 5th grade reading level and takes 35-50 minutes to complete.

MMY (1995) quotes on 16PF:
"This psychometrically sophisticated measure is a valuable contribution to the testing repertoire of counselors and clinicians."
"
...this well-known research instrument has stood the test of time and is supported by a vast body of data."

3. Personal Characteristics Inventory (PCI) - The PCI is a measure of the Big 5 (and subscales) and was developed by Drs. Michael Mount and Murray Barrick, authors of a very influential study on personality testing. It consists of 150 three-choice items that Wonderlic claims are written at 3rd-4th or 8th-9th grade level depending on the scale, and takes about 25-30 minutes to complete.

MMY (2005) quotes on PCI:
"The authors have devised a simple, clear measure of [the Big 5] that may be helpful in some personnel work. Presently available evidence suggests more development work would be necessary...before this reviewer could recommend its use."
"...a good first step in the development of a personnel selection instrument...There are some important reliability and validity issues the authors must address in their revisions."

4. NEO Personality Inventory-Revised (NEO PI-R) - The NEO PI-R is one of several tests of the Big 5 offered by Psychological Assessment Resources (PAR). The test authors, Drs. Paul Costa and Robert McCrae, are well-known researchers and authors of several influential studies on personality testing (hey, who said psychological research doesn't pay?). The test (available in both self-report and observer-report versions) contains 240 items that PAR claims are written at a 6th grade reading level; the test takes 35-45 minutes to complete.

MMY (1995) quotes on NEO PI-R:
"These scales should be considered a standard set of useful tools for personality assessment and may provide a useful bridge between basic research in personality psychology and applied psychology."
"...a reliable and well-validated test of personality features...an instrument that represents a comprehensive operational translation of the Five Factor Model of personality."

So which do I use?

Good question, and there's no easy answer. My advice? First analyze the job(s) and make sure that a test of the Big 5 makes sense given job requirements. Then contact the test publishers and get demonstrations (they should all be willing to do this)--this will allow you to get a feel for the exam as well as the customer service offered by the company. Whatever you do, don't try coming up with a personality test yourself!

1 comment:

Joseph P. Murphy said...

Personality has two distinct variations, as defined by the underlying premis of the instrument used to measure it. A careful examination of the publisher's User's Guide and Technical Manual or Validation Analysis will reveal if the assessment was intended to support a clinical diagnosis or describe occupational traits.

A few publishers and developers of assessments have moved toward the use of the term 'work style' in referring to the preferred approch an individual might take in dealing with job demands.

Work style distances job relevant behaviors from clinical dimensions of personality. This clear distinction adds value to the recruiters in maintaining their objective focus on the work relatedness of candidate evaluation. In addition, work style adds value to the candidate experience in that it directs their attention to their own preferred approach to work.

Both of these distinctions can improve the face validity of the assessment and open the door for candid feedback with candidates. Recruiters find it easier to interpret assessment results reported in terms of work style.

Take time to read the manuals, know what you are measuring.