Validity & Reliability of Our Assessment Instruments

Our assessment instruments include inventories that measure interests, values, skills and abilities, personality type, leisure time interests, and career planning readiness. Our data analysis is based on several groups of system users as follows:

Sample	Sample Size
High School Students	1122
College Students	1651
Adults in Career Transition	996
Prisoners, Parolees, Persons on Probation	564
Youth Development Services - Teenagers	687

Statistical Methods Used
Item-scale correlations and item-factor analyses were calculated for all samples.

• Reliability Measures: Two measures of reliability were computed, one for internal reliability (Alpha coefficient), and one for stability (test-retest).

• Validity Measures: Content Validity and Construct Validity were assessed for all sets of items.
• Content validity was established by (1) examining the face validity of items (2) reviewing the theoretical models and methods used to develop the items, and (3) item-scale correlations
• Construct validity was established by comparing the results of the factor analysis across the different samples. The essential question was, did the factor structure remain the same across the four different population samples.

For all instruments, all items had factor analysis loadings reached or exceeded .67 on their respective factors. Two measures of reliability were computed, one for internal reliability (Alpha coefficient), and one for stability (test-retest). The reliability coefficients for all items reached or exceeded .85. Close inspection of the factor structure across the samples gives support to the construct validity