We remember things better when repeated over time and across environments. #cognition ##### Related studies: 1. Kahana, M. J., & Howard, M. W. (2005). Spacing and lag effects in free recall of pure lists. _Psychonomic Bulletin & Review_, _12_(1), 159-164. **[https://doi.org/10.3758/bf03196362](https://doi.org/10.3758/bf03196362)** 2. Hintzman, D. L. (1976). Repetition and memory. _Psychology of Learning and Motivation_, _10_(1), 47-91. **[https://doi.org/10.1016/s0079-7421(08)60464-8](https://doi.org/10.1016/s0079-7421(08)60464-8)** 3. Küpper-Tetzel, C. E., Erdfelder, E., & Dickhäuser, O. (2014). The lag effect in secondary school classrooms: Enhancing students’ memory for vocabulary. _Instructional Science_, _42_(3), 373-388. **[https://doi.org/10.1007/s11251-013-9285-2](https://doi.org/10.1007/s11251-013-9285-2)** 4. Koval, N. G. (2019). Testing the deficient processing account of the spacing effect in second language vocabulary learning: Evidence from eye tracking. _Applied Psycholinguistics_, _40_(05), 1103-1139. **[https://doi.org/10.1017/s0142716419000158](https://doi.org/10.1017/s0142716419000158)**