Recently, flipped classrooms have received increasing research interest in various disciplines (Gaughan, 2014).Although researchers have identified major psychological factors affecting the quality of the flipped classroom, these factors have not been systematically or simultaneously examined.Drawing on the questionnaire data obtained from 39 university second-language learners of different achievement profiles, this study explores the relative effects of students' accepted workload, preferred form of work (group vs. individual) and perceived usefulness of flipped classrooms on these learners' perceptions and acceptance of a flipped classroom.Additionally, based on these university L2 learners' questionnaire responses, we examined if achievement levels (high vs. low achievers) would modulate the effects of the aforementioned factors.The results showed that high achievers could accept 2 hours of preparatory work prior to class, but that low achievers could only accept 1 hour of work.Additionally, while high achievers prefer individual work, low achievers like to work in groups.Based on the findings of the study, pedagogical implications for the implementation of the flipped classroom for mixed-level students are discussed.