Severity differences among self-assessors, peer-assessors, and teacher assessors rating EFL essays

► We investigated the rating behavior of three assessor types. ► The assessors scored essays that English-as-a-Foreign-Language students wrote. ► Teacher assessors and peer-assessors tended to rate more harshly than self-assessors. ► However, within each assessor type, assessors showed varying degrees of severity. We compared three assessor types (self-assessors, peer-assessors, and teacher assessors) to determine whether they differed in the levels of severity they exercised when rating essays. We analyzed the ratings of 194 assessors who evaluated 188 essays that students enrolled in two state-run universities in Iran wrote. The assessors employed a 6-point analytic scale to provide ratings on 15 assessment criteria. The results of our analysis showed that of the three assessor types, teacher assessors were the most severe while self-assessors were the most lenient, although there was a great deal of variability in the levels of severity that assessors within each type exercised.