The Testing Effect

The Testing Effect is the well-established psychological effect that the mere act of testing someone’s memory will strengthen the memory, regardless of whether there is feedback. The following (Roediger et al, 2006: 181) shows the effect of a multiple choice test taken by students after reading an article on bamboo. They were tested once after a variable interval and then again the same number of days after the test. Those whose first test was after 1 day remembered more than those whose first test was 7 days or 21 days later. Notice that the number of correct answers at first test follows a perfect forgetting curve!

Again, this phenomenon is centuries old. In 1620, Francis Bacon wrote:

“If you read a piece of text through twenty times, you will not learn it by heart so easily as if you read it ten times while attempting to recite from time to time and consulting the text when your memory fails”

and in the Principles of Psychology, James (1890) also argued for the power of testing or active recitation:

“A curious peculiarity of our memory is that things are impressed better by active than by passive repetition. I mean that in learning (by heart, for example), when we almost know the piece, it pays better to wait and recollect by an effort from within, than  to look at the book again. If we recover the words in the former way, we shall probably know them the next time; if in the latter way,  we shall very likely need the book once more.” (p. 646)

The testing effect implies that, when you review material, you should actively challenge your memory to recall it rather than simply re-read or re-study that material. We call this ‘Active Review‘ just to be difficult. Everyone else calls it ‘Active Recall

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  • Roediger, H. and Karpicke, J. (2006) ‘The Power of Testing Memory, Basic Research and Implications for Educational Practice’, Perspectives on Psychological Science Volume 1—Number 3