Title Optimizing Self-organized Study Orders: Combining Refutations and Metacognitive Prompts Improves the Use of Interleaved Practice Summary This study examines the efficacy of a strategy intervention designed to promote the self-regulated use of interleaved practice within a learning task where students can arrange learning materials themselves by making item-based decisions (i.e., which next category to study). Interleaving is defined as switch decisions from one category to another while blocked practice occurred when students stayed within the same category. This intervention consists of two main components: Refutation-based instructions and visual metacognitive prompts. Participants were undergraduate students at Maastricht University. The study was designed and conducted on SoSciSurvey platform. Main research questions were associated with the use of interleaving, students’ learning strategy beliefs, and their classification performance. Data Description 1. Nsw. Number of switches • Chronologically ordered (per task) 2. Sw. Proportion of switches. • Chronologically ordered (per task) 3. PE. Perceived effectiveness of learning strategies • PE_B for blocked practice • PE_I for interleaved practice • Chronologically ordered (per measurement) 4. Condition. Whether students were assigned to the intervention. 5. Classification performance • Experimenter controlled: test.i and test.b; i for interleaved artists and b for blocked artists. • Test 2 and Test 3 scores. 6. Dist. Distance measurement, i.e., second operationalization of interleaving.