AbstractIt is very important to check for validity and reliability of self-report scales or measures. This study aimed to determine the validity and reliability of an instrument which is adapted from Harris and Brown (2008) known as ‘Teachers' Conceptions of Feedback (TCoF) inventory’. The instrument consists of 37 items from 9 constructs namely irrelevance, improvement, accountability, encouragement and self-type, task, process, self-regulation, peer and self-assessment and timeliness. One hundred and eighty-five (N=185) undergraduate students who are also the student teachers had completed the questionnaire. Respondents used a six-point agreement rating scale coded as strongly disagree=1, mostly disagree=2, slightly agree=3, moderately agree=4, mostly agree=5 and strongly agree=6. The content was validated by three experts in the field of measurement and evaluation. Data analysis was completed using the Rasch measurement model. The findings revealed that most items fit the model as their.....