INSIGHT Inventory Research & Development

Statistics, Reliability & Validity

Users of personality measures, type indicators, or behavioral assessments can learn a great deal about an instrument’s usefulness by examining its test statistics. These consist of reliability, validity, and normative data supported by descriptive information about the underlying theory and process of development.

When publishers and authors don’t provide test statistics, won’t make research information available, or maintain this data is private or confidential (by claiming they are “protecting trade secrets”) then, those instruments should be considered suspect and are likely invalid. When good solid data is available, authors are proud of it, seek to share it, and strive to encourage more research.

The INSIGHT Inventory has been thoroughly researched and carefully developed by Patrick Handley, Ph.D. and licensed psychologist. The data is openly available in a published technical manual. To further insure unbiased reporting, an independent review and analysis was conducted by Dr. Thom Krieshock, Chairman of the Department of Counseling Psychology, at the University of Kansas. In addition, the INSIGHT Inventory has received favorable reviews by the independent test review authority, the Buro’s Mental Measurement Yearbook. Plus, numerous doctoral and master’s theses have been completed on the INSIGHT Inventory.

Dr. Handley is proud of the INSIGHT Inventory’s strong research base and makes all statistics public. A 100+ page technical manual is available for review or purchase. The information on this web site has been abbreviated and condensed and is meant only to serve as a short overview and summary of key data.

Reliability

Reliability is the degree of consistency with which a test measures what it is said to measure. Test length greatly affects reliability coefficients, with longer tests traditionally producing higher scores. Dr. J.C. Nunnally stated in the classic reference book, Psychometric Theory, © 1978, that internal consistency reliability coefficients for short personality tests should range in the .70’s to .80’s. For example, the well-researched Myers-Briggs Type Indicator reports internal consistency reliability for its four scales on general population samples to range from .61 to .87. Internal consistency reliability was computed on each of the four scales of the much shorter INSIGHT Inventory and the results ranged from .71 to .85. Thirty day test-retest reliability produced scores ranging from .76 to .82. Given its very short length, the INSIGHT Inventory produced very solid reliability coefficients.

Validity

The validity scores of a test estimate how well the test measures what it purports to measure. Personality assessment tests usually produce validity scores for each of the individual traits measured. When scores on the traits of a test correlate well with scores on similar traits on other tests, the test is said to have good concurrent validity. Validity coefficients were computed on each of the four INSIGHT Inventory traits by comparing these to the traits measured by the Myers-Briggs Type Indicator (MBTI), Sixteen Personality factors (16PF), and Holland Self-Directed Search (SDS). This data comprises a large section of the INSIGHT Technical Manual and users are encouraged to review those pages and tables. Very strong support for the validity of the traits measured by the INSIGHT Inventory was garnered.

Technical Characteristics

The INSIGHT Inventory is a self-report, personality inventory that measures the intensity of four bipolar traits: Scale A–Influencing, Direct or Indirect; Scale B–Responding, Reserved or Outgoing; Scale C–Pacing, Urgent or Steady; and Scale D–Organizing, Unstructured or Precise. Thirty-two terms, primarily adjectives and short descriptive phrases derived through factor analysis, make up the item pool. Based on Kurt Lewin’s Field Theory, the INSIGHT Inventory measures behavior in two environments (fields); participants first rate how they see themselves at work (field 1); then rate how they see themselves at home (field 2). The Inventory takes approximately ten minutes to complete and an additional five to ten minutes to score. The step-by-step participant’s booklet provides an interpretation of the results and guidelines for applying the information.

Item Analysis

Item analysis establishes the statistical relationship between items of an inventory and the traits they measure. If no item analysis is done then the matching of an item to a particular trait is essentially a guess on the test developer’s part. An initial sample of 1540 individuals completed the INSIGHT Inventory and a factor analysis of their scores was computed to select the items which loaded most heavily on the four factors (scales).