Because writing Evergreen notes with dense associative structure (see Evergreen notes should be densely linked) requires that we constantly reread and revise our past writing, this type of note-taking approximates spaced repetition.
In particular, the spaced repetition follows your present interests. If you stop reading or writing about a given topic, you’ll mostly never revisit it. If you’re regularly reading or writing about a topic, you’ll revisit that prior material fairly constantly.
This isn’t an efficient spaced repetition, memory-wise: you’re not really taking advantage of the Testing effect. But it does take advantage of something like the Generation effect, and it may be a useful lens to think about managing your attention across the corpus of ideas you accumulate over time. Specifically, this practice will encourage you to repeatedly give attention to past ideas which seem relevant to your present work. And because you may find yourself revising your notes on those past ideas, the attention may be quite effortful.
This same effect occurs when maintaining systems which involve Transclusion.
Ahrens, S. (2017). How to Take Smart Notes: One Simple Technique to Boost Writing, Learning and Thinking – for Students, Academics and Nonfiction Book Writers.
We learn something not only when we connect it to prior knowledge and try to understand its broader implications (elaboration), but also when we try to retrieve it at different times (spacing) in different contexts (variation), ideally with the help of chance (contextual interference) and with a deliberate effort (retrieval). The slip-box not only provides us with the opportunity to learn in this proven way, it forces us to do exactly what is recommended just by using it.
When you try to recall some detail from memory, that act strengthens your memory of that detail. When exploited as a learning activity, this is called “retrieval practice.”
Experiment has demonstrated this effect even when the correct answer is not provided (though Retrieval practice may be less effective without feedback), and even when the test-taker is given “open-book” access to find a correct answer. The effect has been demonstrated in many fields and at many age levels.
This suggests a significantly different role for tests. In typical classrooms, teachers and students imagine that learning happens during lectures, or while reading the material. The tests are there to assess that learning. But in fact, the tests themselves are an important part of the learning process.
Retrieval practice leads to more durable long-term memory than simply studying material by e.g. re-reading, despite the fact that students will be less successful during practice itself (Roediger, 2006). Related: Desirable difficulties, after Bjork.
It also seems to lead to more durable memory (Karpicke and Smith, 2012) and improved learning performance in general (Karpicke and Blunt, 2011) relative to Elaborative encoding-based practice alone.
The testing effect may be diminished or inverted for immediate tests
The testing effect is generally measured to be more pronounced for production tests (short answer, essay) than for discrimination (multiple choice / true-false) (e.g. Kang et al, 2007). This may be due to the Generation effect.
A few cites to follow up on here from Agarwal, P. K., Nunes, L. D., & Blunt, J. R. (2021). Retrieval Practice Consistently Benefits Student Learning: A Systematic Review of Applied Research in Schools and Classrooms. Educational Psychology Review.:
n.b. that Pan, S. C., & Rickard, T. C. (2018). Transfer of test-enhanced learning: Meta-analytic review and synthesis. Psychological Bulletin, 144(7), 710–756 find a medium-large effect (d=0.58) for transfer across initial and final test formats
Pan, S. C., & Rickard, T. C. (2018). Transfer of test-enhanced learning: Meta-analytic review and synthesis. Psychological Bulletin, 144(7), 710–756, focused specifically on Retrieval practice and transfer learning
Branwen, G. (2009). Spaced Repetition for Efficient Learning. Retrieved December 16, 2019, from https://www.gwern.net/Spaced-repetition
Roediger, H. L., & Karpicke, J. D. (2018). Reflections on the Resurgence of Interest in the Testing Effect. Perspectives on Psychological Science, 13(2), 236–241. https://doi.org/10.1177/1745691617718873
Roediger, H. L., & Butler, A. C. (2011). The critical role of retrieval practice in long-term retention. Trends in Cognitive Sciences, 15(1), 20–27. https://doi.org/10.1016/j.tics.2010.09.003