Rating Scales in Survey Research: Using the Rasch model to illustrate the middle category measurement flaw

Abstract

The quality of the instrument used in the measurement process of survey data is fundamental to successful outcomes. Issues regarding content and structure are primary during instrument development, but the rating scale is just as important. Specifically for Likert-type questionnaires, the words used to describe rating categories and the placement of a neutral or not sure category is at the core of this measurement issue. This study utilizes the Rasch model to assess the quality of an instrument and structure of the rating scale for a typical data set collected at an institution of higher education. The importance of category placement and an evaluation of the use of a neutral middle category for Likert-type survey data is highlighted in this study. Introduction