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“For example, many teachers and practice review sources firmly linked retrieval practice and spaced practice. Both are forms of desirable difficulty for which the effects may not be entirely additive, as explained in a point by Putnam and Roediger:
‘Combining retrieval practice with spacing creates an interesting situation, however, because retrieval practice is more effective when it is successful, but increasing the gaps between retrieval practice opportunities makes retrieval more difficult (less successful). Thus, the positive effects of spacing and retrieval practice may be working against one another, at least when no feedback is provided on the test.’ (Putnam and Roediger, 2018, p. 177) page 84.
However if one can get the timing right, and timely practice usually can, get the timing right so one can increase the spacing between retrieval practices and ensure the learner is successful (because the timing is personalised, so one can gradually increase the durability of recall-ability) we should see the benefits of retrieval practice and spacing.
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