• Chanchai Hosanguan B.Sc. (Hons), D.D.S. (Hons), M.S.

Objective The Professional Role Orientation Inventory has been cross-culturally adapted for Thai
dentists. The purpose of this study was to evaluate reliability and validity of its Thai version.

Materials and methods A random sample of 792 dentists (Sample A.) responded to mailed questionnaires.
Factorial validity of the inventory was assessed by exploratory factor analysis. Item-level
construct validity was assessed by convergent and discriminant validities. Cronbachûs alphas were
computed for assessing internal consistency as well as Spearman-Brown coefficients for split-half
reliability. In addition, a sample of 234 dentists (Sample B.) returned a second questionnaire for
assessing test-retest reliability using intraclass correlation coefficients (ICC).

Results An exploratory factor analysis revealed a five-factor structure consisting of authority, responsibility,
autonomy, agency, and authority-responsibility. All dimensions, excepting autonomy, demonstrated
good item convergent and discriminant validities. Cronbachûs alphas ranged from 0.25 to 0.85.
Spearman-Brown coefficients were between 0.34-0.87. Item-level ICCs were between 0.32-0.60.

Conclusion Some dimensions of the inventory displayed unsatisfactory level of reliability and validity.
Specifically, the factorial structure of the Thai version did not conform to the original inventory.
Psychometric properties of the inventory need further improvement before meaningful assessment of
professionalism among Thai dentists could be achieved.

(CU Dent J. 2009;32:53-68)