We investigated how using a ready-made versus self-generating a graphic organiser (GO) affected undergraduate students’ learning from an educational document. Two groups of students were compared: students who learned from an educational document accompanied by a ready-made GO (n = 19) and students who were instructed to self-generate a GO from the same educational document using an editing tool (n = 18). Previous research has shown that adding GOs to educational documents improves students’ learning by highlighting the main ideas of the text and their interrelations. However, studies focusing on self-generation effects have reported mixed results on learning when comparing ready-made versus self-generated GOs. In this study, we investigated a new mode of GO self-generation in which students were asked to create one by simply organising the main ideas of the text. The results showed that this self-generation activity negatively influenced the students’ retention and transfer scores compared with those of the students who viewed a ready-made GO. We hypothesise that the self-generation activity distracted the students, thereby hindering their learning. Future studies should provide learners with guidance during the learning process so that they can benefit from self-generative activities.