Singer-Loomis Psychometrics

Interpretive Notes

Beginning with Loomis and Singer’s initial evaluation of the performance of the Singer-Loomis, Chronbach’s Alpha was used to assess the reliability and the internal consistency of the various scales in the Inventory. This well-regarded measure was used by all of the subsequent evaluations of the Singer-Loomis. The measures reported in each of the four tables below are alpha coefficients. Consequently, comparison of the several studies is remarkably straightforward. Interpretation of the scores is dependent upon the number of items in the scale with the level of acceptable performance being lower with Type Modes (20 items), higher with Type Functions (40 items) and highest with Extraverting, Introverting, Perceiving and Judging—each of which is based on 80 items.

The internal consistencies of the shorter scales (the lowest level of aggregation) were somewhat smaller than those of the longer scales. However, this is to be expected, because coefficient alpha is partially dependent on item variances, which can be affected by the number of items. ….Nevertheless, despite the relatively lower reliability of scores from these shorter scales, the internal consistencies are in the acceptable range.[i]

Some of these studies, most notably Arnau, et. al. and Illiescu and Minulescu, employed additional forms of evaluation.

*Aggregate measure based on 4 variables measured 20 times each = 80 items/observations

*Aggregate measure based on 2 variables measured 20 times each = 40 items/observations

*Single variable 20 items/observations

*Single variable, 20 items/observations

References

Arnau, R, Rosen, D. & Thompson, B. (2000). Reliability and validity of scores from the Singer-Loomis Type Deployment Inventory, Journal of Analytical Psychology, 45, 409-426

Illiescu, Dragos and Minulescu, Mihaela (2010). Singer-Loomis Type Deployment Inventory. D&d/Test Central: Bucharest, Romania.

Kirkhart, Elizabeth and Kirkhart, Larry (1996). Comparison of Eight Psychological Inventories. Revised. Moving Boundaries, inc.: Gresham, Oregon.

Kirkhart, Elizabeth and Kirkhart, Larry (1999). Statistical Performance of the Singer-Loomis Type Deployment Inventory: An Interim Report. Moving Boundaries, inc.: Gresham, Oregon.

Kirkhart, Elizabeth and Kirkhart, Larry (2003). Technical Manual for the Singer-Loomis. Moving Boundaries, inc.: Gresham, Oregon.

Singer, June and Loomis, Mary (1980). Technical Manual for the SLIP. Consulting Psychologists Press: Palo Alto, CA.

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[i] Illiescu, Dragos and Minulescu, Mihaela (2010). Singer-Loomis Type Deployment Inventory. D&d/Test Central: Bucharest, Romania, p. 143.

[ii] Kirkhart, Elizabeth and Kirkhart, Larry (2003). Technical Manual for the Singer-Loomis. Moving Boundaries, inc.: Gresham, Oregon. p. 16.

[iii] T1 and T2 represent a Test-Retest administered two weeks apart. Arnau, R, Rosen, D. & Thompson, B. (2000). Reliability and validity of scores from the Singer-Loomis Type Deployment Inventory, Journal of Analytical Psychology, 45, 416-417

[iv] Kirkhart, Elizabeth and Kirkhart, Larry (1999). Comparison of Eight Psychological Inventories. Revised. Unpublished manuscript. p5

[v] Kirkhart, Elizabeth and Kirkhart, Larry (1996). Comparison of Eight Psychological Inventories. Revised. Moving Boundaries, inc.: Gresham, Oregon, p. 5.

[vi] Singer, June and Loomis, Mary (1980). Technical Manual for the SLIP. Consulting Psychologists Press: Palo Alto, CA, 13

[i] Arnau, R, Rosen, D. & Thompson, B. (2000). Reliability and validity of scores from the Singer-Loomis Type Deployment Inventory, Journal of Analytical Psychology, 45, ???