Roediger and his coauthors in Make It Stick describe it this way: “Unsuccessful attempts to solve a problem encourage deep processing of the answer when it is later supplied, creating fertile ground for its encoding, in a way that simply reading the answer cannot” (Brown, Roediger, and McDaniel 2014, p. 88). The ground is fertile because the learner's brain has now activated several connections between the question and other possible contexts, and when the answer arrives in the soil it takes hold more quickly and firmly because of the link between the answer and those other contexts.
