Summary writing assessment concerns persist regarding its reliability, validity, and practicality in educational settings, as evaluating various abilities and skills complicates the process. Therefore, this investigation aimed to examine the rating strategies and awareness of assessing summaries written by Japanese university students, focusing on raters with diverse backgrounds, such as native or non-native English speakers and novices or experts.

The study results show that some items did not provide sufficient reliability among experienced raters, even with adequate training. In contrast, it produced higher reliability among inexperienced ones. Furthermore, rating agreements and score decisions did not differ by raters' native language. Instead, these differed depending on the raters’ experience. However, no significant differences were found among the raters’ strategies during the evaluation.