Most people treat practice tests as a way to figure out what they don't know yet. A diagnostic. Something you do right before an exam to see where you stand. But the research says something even more interesting: the act of taking the test itself builds your memory. If this sounds like you, reframe your perspective; you shouldn't take a practice test because you're ready. You should take it because taking it makes you ready. And that same principle applies to everything you're trying to learn.
What is it?
Active recall is the umbrella principle: instead of passively re-exposing yourself to information, you force your brain to retrieve it from memory. Closing your notes and trying to write down everything you remember. Answering questions before looking up the answer. Explaining a concept out loud without looking at your slides. Any time your brain is pulling information out rather than taking it in, that's active recall. You often store much more than you know. All it takes is some deep digging, and you can solidify the information that you have already exposed yourself to, instead of just trying to jam more information in.
The testing effect is the most well-documented and powerful version of this. It refers to the finding that being tested on material produces dramatically stronger long-term retention than spending the same amount of time restudying it. And crucially, this holds even when you get answers wrong. The attempt to retrieve, successful or not, strengthens the memory trace in a way that rereading simply cannot replicate.
The Neuroscience
When you retrieve information from memory, something fundamentally different happens compared to when you simply reread it. Each time your brain successfully pulls out a memory, the synaptic connections associated with it get strengthened through a process called long-term potentiation, essentially the cellular mechanism behind how memories are consolidated and made more durable. Think of it like pushups: the more you do them, the easier they get. Passive review, on the other hand, lets information wash over you without triggering the deeper reconstructive work that actually builds lasting neural pathways. You aren't able to do more pushups just from watching a video; at some point, you need to practice the movement itself to actually improve.
A big part of why retrieval works so well comes down to a small, seahorse-shaped structure deep in the brain called the hippocampus. It acts as the brain's gatekeeper for long-term memory, deciding what gets stored and what gets lost. When you passively reread your notes, the hippocampus barely engages. When you actively retrieve, it kicks into gear, reconstructing the memory and in doing so, making it stronger and easier to access next time. This is also why getting something wrong and then looking up the correct answer tends to make it stick better than if you had just read it passively. The failed attempt followed by the correction creates a stronger impression than no attempt at all.
The testing effect specifically refers to what happens when this principle is applied through self-testing. Active recall activates the testing effect, whereby your brain is more likely to move information from short-term memory, held temporarily in the prefrontal cortex, into long-term storage in the cortex via hippocampal consolidation. Repeated testing during learning has been shown to produce substantially greater retention than repeated studying over the same period, even when no feedback is given on whether answers were correct.
This is also why you shouldn't view getting an answer wrong on a practice test as a setback, because it is actually an inherent part of the mechanism. The attempt to retrieve, even a failed one, strengthens the memory trace in a way that rereading simply cannot replicate.
How Can You Use It This Week?
- Swap the last 10 minutes of every study session for a self-quiz instead of more reading.
- Use the blank page method at the end of class.
- Try a spaced repetition flashcard app like Quizlet, Anki, or Brainscape.
- Make your own practice tests from your notes before an exam — use AI to do this to cover everything efficiently!
Close your notes completely and write down everything you can remember about what you just studied. Don't check anything until you're done. Whatever you can't recall is exactly what needs more attention.
- After a meeting or important conversation, write down the 3 most important points discussed before doing anything else.
- After reading a book, article, or even a podcast, pause and summarize the main ideas in your own words before moving on.
