Investigating the Effect of Rater Training on Differential Rater Function in Assessing Academic Writing Skills of Higher Education Students

This study aimed to examine the effect of rater training on differential function (rater error) in process assessing academic writing skills higher education students. The was conducted with a pre-test and post-test control group quasi-experimental design. research consisted 45 raters, whom 22 came from experimental, 23 groups. raters were pre-service teachers who did not participate any before, it investigated that they had similar experiences assessment. data collected using an analytical rubric developed by researchers opinion-based task prepared International English Language Testing System (IELTS). Within scope research, compositions 39 students written foreign language (English) assessed. Many Facet Rasch Model used for analysis data, this under Fully Crossed Design. findings revealed given effective function, suggestions based these results presented.