extended · article · 2021

Applying the Rasch Rating Scale Model (RSM) to investigate the rating scales function in survey research instrument

Jimmy Chong; Siti Eshah Mokshein; Ramlee Mustapha; David Andrich

The functionality and quality structure of a rating scale are vital in a survey instrument. This article discusses the underlying assumption of a rating scale and addresses the application of the Rasch Rating Scale Model (RSM) to diagnose the rating scale structure in a survey instrument. The instrument used to demonstrate the process of diagnosis a rating scale functioning in this study was the Vocational Teachers' Assessment Literacy (VoTAL) instrument. The VoTAL instrument utilized the five-point Likert-type response format and consisted of 88 items representing three assessment literacy constructs. The data were obtained from 224 vocational teachers at five vocational colleges, which were randomly selected from the state of Selangor and the federal territory of Kuala Lumpur in Malaysia. The rating scale diagnosis results showed that the initial five steps of rating scale categories w...