The pattern here runs differently from a simple "popular claims get less scrutiny" story. Highlighting and re-reading are extremely popular study habits, and yet every usable result we checked disclosed that the research rates them low-utility; the low-utility finding itself has become common knowledge, so the disclosure IS the popular narrative now.

Learning styles is the opposite case: it is arguably the single most debunked idea in education research, cited in dozens of studies as a myth, but the pages that rank for the term overwhelmingly describe how to identify and teach to a "style" rather than noting the idea does not hold up. A reader who searches "learning styles" today is more likely to get a quiz than a correction.

Two findings that frame everything above

1. Desirable difficulties

Several of the most effective techniques (retrieval, spacing, interleaving) share a counterintuitive property: they make studying feel harder and slower in the moment, yet produce stronger long-term retention. Conditions that speed up apparent learning during practice often weaken it long term, and vice versa.

This is Robert Bjork's concept of "desirable difficulties," and it explains why learners systematically prefer less effective strategies: the easy ones feel like they are working.

2. The performance-learning distinction

Performance is what you can do during or immediately after study, under supportive conditions. Learning is what remains after a delay and generalises to new contexts. They frequently dissociate.

Because learners and instructors usually observe performance, not learning, intuitive judgments about "what's working" are unreliable - which is the practical reason this evidence map exists.

Methodology and scope notes

  • What counts as evidence here: peer-reviewed experimental research and meta-analyses/syntheses. Where a row cites a synthesis (e.g. Dunlosky et al., 2013), the rating reflects that synthesis's assessment of utility, not a single study.
  • Effect sizes are conditional. They depend on population, material type, retention interval, and design. This map reports evidence strength and direction, not guaranteed magnitudes for any individual.
  • Lab vs. classroom. Much of the strongest evidence comes from controlled studies; classroom replications generally support the same directions but with smaller and more variable effects. Treat real-world gains as smaller than lab maxima.
  • This is not advice for a specific person or condition. It summarises general findings about typical learners; it is not individualised educational, clinical, or accessibility guidance.
  • Maintenance: this page is updated when the underlying evidence base changes materially, not on a fixed schedule. A visible "last reviewed" date reflects a real review.
  • Search transparency gap methodology: for each technique, we searched its plain common name and checked the top 10 organic (non-ad, non-video) results, real general-audience articles, encyclopedia entries, or reference pages. Pages that could not be fetched or parsed were excluded from the denominator rather than counted as non-disclosing, so sample sizes actually checked ranged from 5 to 10 usable pages per technique. A single disclosing sentence anywhere on the page counted as disclosure, a low bar, so the percentages likely understate rather than overstate the real transparency gap. This is one search snapshot, not a tracked index; a different query phrasing would return a different set of pages. Measured August 2026; we plan to re-run this measurement periodically.

Sources checked: the raw audit

For transparency, every page we checked for the search transparency gap measurement above is listed below, one collapsible section per row, with our verdict and the exact disclosing sentence where one was found. This is the full working, not a summary of it.

Learning styles (meshing hypothesis): 2 of 7 disclosed
Spaced practice: 4 of 10 disclosed
Worked examples: 4 of 8 disclosed
Interleaving: 5 of 8 disclosed
  • effectiviology.com: disclosed. "in some cases, it's no better than blocked practice, and can even be worse"
  • psychology.ucsd.edu: disclosed. "Examples of materials that interleaved practice can benefit include similar types of math problems, easily confused grammatical tenses, and similar classes of visual stimuli."
  • arc.duke.edu: not disclosed
  • structural-learning.com: disclosed. "the benefits may reverse if topics are too dissimilar, particularly with vocabulary learning"
  • edweek.org: disclosed. "Neither massed practice nor interleaving alone results in deep mastery. It takes both."
  • ctl.wustl.edu: not disclosed
  • mlpp.pressbooks.pub: excluded, page unreadable
  • cei.umn.edu: excluded, page unreadable
  • coursera.org: not disclosed
  • scientificamerican.com: disclosed. "Otherwise, interleaving can sometimes be more confusing than helpful."
Elaborative interrogation: 5 of 7 disclosed
  • en.wikipedia.org: not disclosed
  • vaia.com: excluded, page unreadable
  • litfl.com: excluded, page unreadable
  • learningscientists.org: not disclosed
  • structural-learning.com: disclosed. "If students do not yet know enough to generate a plausible explanation, they will produce incorrect elaborations."
  • arc.duke.edu: excluded, page unreadable
  • learningscientists.org: disclosed. "Elaboration has been shown to help students who are more familiar with the topic, while those who are less familiar don't benefit as much."
  • uwlax.edu: disclosed. "Some research indicates that students need background knowledge of a topic in order to produce good explanations."
  • smowl.net: disclosed. "One of the main mistakes often made when implementing this technique in the classroom is that students do not have prior knowledge of a topic."
  • frontiersin.org: disclosed. "Elaborative interrogation are especially beneficial for learners that already possess a relatively high amount of prior knowledge, but less for learners with rather low prior knowledge."
Retrieval practice: 8 of 10 disclosed
  • en.wikipedia.org: disclosed. "Some researchers have applied aspects of cognitive load theory to suggest the testing effect may disappear with increasing task difficulty due to increased element interactivity."
  • ctl.wustl.edu: disclosed. "One possible disadvantage to open-book settings is that they may have the unintended effect of reducing student time spent studying if the students know that the future activity will be open book."
  • structural-learning.com: disclosed. "Feedback significantly changes how well retrieval practice works"
  • studyingmachine.com: not disclosed
  • mike-taylor.org: not disclosed
  • ncbi.nlm.nih.gov: disclosed. "generalization from the laboratory context to educational environments may not be entirely warranted"
  • ncbi.nlm.nih.gov: disclosed. "the testing effect is more robust when test-trials involve more effortful retrieval (e.g., recall vs. recognition)"
  • ncbi.nlm.nih.gov: disclosed. "The backward testing effect is often quite small or even absent when the retention interval between study and test is relatively short."
  • ncbi.nlm.nih.gov: disclosed. "A 2021 meta-analysis found virtually no advantage (Hedges' g = 0.095) of retrieval practice over various forms of elaborative learning strategies."
  • frontiersin.org: disclosed. "virtually no advantage of retrieval practice over various forms of elaborative learning strategies"
Highlighting / re-reading: 8 of 8 disclosed
  • psychologicalscience.org: disclosed. "Rereading and highlighting , seem to provide minimal benefits to their learning and performance."
  • ideas.time.com: excluded, page unreadable
  • edutopia.org: disclosed. "Most studies have shown no benefit to highlighting (as it is typically used) over and above the benefit of simply reading."
  • learningcenter.unc.edu: disclosed. "Highlighting tends not to be a very effective reading strategy."
  • kent.edu: disclosed. "Rereading and highlighting , seem to provide minimal benefits to their learning and performance."
  • pubmed.ncbi.nlm.nih.gov: excluded, page unreadable
  • facultyfocus.com: disclosed. "Research on study strategies rated rereading as having low utility."
  • lawschooltoolbox.com: disclosed. "Both highlighting text and rereading text surprisingly received a Low Utility rating."
  • innerdrive.co.uk: disclosed. "Compared to other learning strategies, such as Retrieval Practice, research has shown that highlighting to improve learning and memory tends to fare quite poorly"
  • learningscientists.org: disclosed. "Never use highlighting as the ONLY means of studying."
Self-explanation: 5 of 5 disclosed
  • learning.northeastern.edu: disclosed. "After-the-fact explanation also has an impact, but it is not as effective as explaining in the moment."
  • psychology.ucsd.edu: disclosed. "Other methods may also be helpful (however there is less available research and/or only specific types of information may benefit)."
  • lib.sfu.ca: excluded, page unreadable
  • innerdrive.co.uk: disclosed. "Other research has suggested that self-explanation is more beneficial for subjects such as science and maths, as it is particularly suited to subjects that require reasoning or problem solving."
  • biointeractive.org: excluded, page unreadable
  • takinglearningseriously.com: disclosed. "Self-explaining will not be very effective if you have very little knowledge of the material."
  • activerecalling.com: excluded, page unreadable
  • kaporfoundation.org: disclosed. "Can be less effective if students do not have any prior knowledge to make connections with new material."
  • ablconnect.harvard.edu: excluded, page unreadable

Sources

All sources are peer-reviewed and linked to their DOI or canonical record. These are the primary references behind the ratings above.

  • Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students' learning with effective techniques: Promising directions from cognitive and educational psychology. Psychological Science in the Public Interest, 14(1), 4-58. View source
  • Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249-255. View source
  • Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354-380. View source
  • Kornell, N., & Bjork, R. A. (2008). Learning concepts and categories: Is spacing the "enemy of induction"? Psychological Science, 19(6), 585-592. View source
  • Rohrer, D., & Taylor, K. (2007). The shuffling of mathematics problems improves learning. Instructional Science, 35, 481-498. View source
  • Sweller, J. (1988). Cognitive load during problem solving: Effects on learning. Cognitive Science, 12(2), 257-285. View source
  • Pashler, H., McDaniel, M., Rohrer, D., & Bjork, R. (2008). Learning styles: Concepts and evidence. Psychological Science in the Public Interest, 9(3), 105-119. View source
  • Bjork, R. A., & Bjork, E. L. (1992). A new theory of disuse and an old theory of stimulus fluctuation. In A. Healy, S. Kosslyn, & R. Shiffrin (Eds.), From Learning Processes to Cognitive Processes (Vol. 2, pp. 35-67). Erlbaum.