Testing builds memory

Testing isn’t just a way of assessing whether things have been learned – it’s one of the most effective ways to learn.

Its primary benefit is as a way of helping us to learn, due to the ‘testing effect’. By trying to recall something (i.e. testing ourselves), we strengthen our memory. This effect seems to be most powerful when we are on the cusp of forgetting something. That’s because the greater the cognitive effort involved in trying to recall something, the more it strengthens memory.

Active recall (or retrieval practice) strengthens long-term memory significantly more than re-reading. Even when we feel we don’t know anything about a topic, just the act of guessing results in improved retention when we are subsequently presented with the information.

Research evidence

In a 2006 study, researchers Roediger and Karpicke gave three groups a short text to read and remember. The first group re-read the text several times before taking a memory test a week later, the other two groups had at least one practice test before the final memory test.

Students who did practice tests and no re-reading (Group 3) recalled 50% more after a week than those who only re-read the texts (Group 1), even though students in Group 3 read the passage only 3.4 times and those in Group 1 read it 14.2 times.

There is good evidence that simply re-reading or highlighting has very little effect. Rather than re-read information, we’ll get more value from trying to recall it.

An interesting metacognition point is that in research studies, participants were convinced that re-reading and highlighting was more effective – but the results proved otherwise.


As a learner, try to think of the answers before they’re revealed. Test yourself rather than re-reading. Research shows that testing ourselves on things we don’t even know at all makes it more likely that we’ll remember them when we’re subsequently presented with the information or answer. Alternatively, try writing down everything you can think of about the topic before studying it

As a learning designer, don’t spoon feed the answers to learners – build in frequent low-stakes tests.