This study aims to investigate how undergraduate trainee translators interpret guidelines for Chinese-to-Korean machine translation post-editing. To this end, 15 undergraduate trainee translators were asked to perform Chinese-to-Korean machine translation post-editing with two different types of text (a report and a speech). The machine translation engine used was NAVER Papago. After that, retrospective interviews were conducted with four students who had written commentaries on their own translations. Results show that some explanations of syntax and punctuation needed to be omitted, while some explanations of lexis needed to be revised to the level that students can understand. It was also found that students needed not only theoretical descriptions of editing criteria but examples of how the criteria can be applied in practice. It was thus necessary to add specific and detailed examples to items that students felt confused, such as style and consistency.