Asghar Minaei; marzieh hasani
Abstract
The current study aimed to improve precision and item functioning of the OHQ by applying Rasch analysis to a sample of 212 participants. A convenience sample of 212 college students (139 girls and 78 boys) from a number of universities in Tehran city completed the OHQ questionnaire. Data were analyzed ...
Read More
The current study aimed to improve precision and item functioning of the OHQ by applying Rasch analysis to a sample of 212 participants. A convenience sample of 212 college students (139 girls and 78 boys) from a number of universities in Tehran city completed the OHQ questionnaire. Data were analyzed using Rasch analysis approach using RUMM2030 software. Results indicated that a number of the OHQ items displayed disordered thresholds. Therefore, items were rescored in a uniform fashion to correct the thresholds. Furthermore, three items (18, 19, and 25) displayed poor fit to Rasch model and were removed. Best fit to the unidimensional Rasch model was achieved after rescoring items in uniform fashion and removing items number 18, 19 and 25. Using the ordinal-to-interval conversion tables published here, ordinal OHQ scores can now be transformed to interval level data and thus subjected to parametric statistical analysis without violating fundamental assumptions. The precision of the instrument can be improved significantly by these minor modifications without the need to modify the original response format.
