Construct Validity Study
Laura Gilbert Ph.D.
Organizational Development and Research Consultant
September 8, 1997
International Assessment Network 7600 France Avenue South Suite 550 Minneapolis, MN 55435
Re: Construct Validity Study Between MAPP and Strong
This document sets out the process that was used to conduct the construct validity study which compares the MAPP to the Strong Interest Inventory. The current analysis yielded correlations which suggest similarity between the underlying constructs of the MAPP and those of the Strong. Additional studies with larger sample populations are expected to further illuminate this relationship as well as satisfy future reviews by educational professionals.
Process for analysis of construct validity between the MAPP and the Strong
In the first step of analysis of construct validity between the MAPP and the Strong, predictions were made as
to the occupational matches between MAPP and Strong. Predictions were made and noted by three senior managers with an average of 17
years experience with job analysis, career development, and performance management. Each represented a different discipline (human
resources, finance, and technology). Differences were discussed and final agreement was reached on each match. Although predicted
matches for each MAPP occupation were held to a standard of three Strong occupations or less, agreement was reached for a single or
dual occupation prediction for the majority of MAPP occupations. Four exceptions were made to allow for more than three predicted
Strong matches in the case of single, broad MAPP occupations such as "Scientific Research" which could equally be predicted to match
Strong occupations "Biologist", "Chemist", Physicist", and "Geologist". (see Appendix A)
Both instruments were then administered to 30 individuals ranging in age from 26-67, with 12 men and 18 women. Scores
were calculated and a full correlation of all MAPP occupations with all Strong occupations was conducted. (see Appendix B) Correlations
for the occupation-match predictions were identified and a single best predicted match was determined. (see Appendices C and D) Of the 80
Strong occupations with a predicted MAPP match, 5 correlations were shown to be reflective of opposing instrumental themes (e.g. Mental Health
v. Social) and had correspondingly low correlations (.14-.41). The remaining 75 correlations between the predicted occupational matches ranged
from .50-.92 with a median correlation of .67. This is particularly noteworthy given that this average correlation is nearly as high as the
average correlation found in an earlier study between the Strong and another assessment tool which was designed to measure the same key
dimensions as the Strong (Harmon, 1994, p. 59).
An earlier comparative study between the Strong and yet a different instrument found only 3 correlations (out of 182) to be
over .30 (Harman, 1994, p. 59). Approximately 85% of the totality of correlations in the current study fall above this marker. The earlier
study did find several interesting directional correlations between itself and the Strong (e.g. Strong "Artistic" correlated negatively
with 'Order" and positively with 'Change' on the comparing instrument). Similar and stronger directional correlations were observed
between the MAPP and the Strong. These relationships are found in the form of negative as well as positive correlations. For example,
MAPP's "Consulting, Business Services" correlated positively to the Strong's "Realtor" (.73), "Corporate Trainer" (.72) and "Chiropractor"
(.69) and negatively to "Farmer" (-.65) and "Plumber" (-.75). These directional correlations reflect the specific instrument's definitions
of these occupations. A chart including all directional relationships with correlations > + or -.65 within the current study can be seen in
Appendix E. The cutoffs of + or -.65 were chosen to be reflective of the median correlation between predicted occupational match items.
Further analysis of the full correlational matrix between MAPP and Strong occupations revealed additional correlations greater than
.65 or less than -.65 beyond those predicted prior to testing. These correlations were identified for each individual MAPP occupation
(see Appendix #) and hypotheses were formulated regarding potential underlying themes using pattern matching among these highly
correlating occupations (see Appendix F). These hypotheses might serve as the basis for further research exploring potential additional
or specific cross-utilizations of the MAPP and Strong. It must be noted, however, that within the limits of the current study these
hypotheses are merely exploratory in nature.
Laura Gilbert, Ph.D. Lgilbert@gw.hamline.edu
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