Desirable Difficulties Perspective on Learning

Learning versus Performance

Basically, current performance, which is something we can observe, is an unreliable index of learning, which we must infer. The distinction between learning and performance goes back to research carried out during the 1930s and into the 1950s—research that demonstrated that considerable learning could take place across periods when there were no systematic changes in performance. Experiments on latent learning, for example, showed that rats, after a period of wandering, apparently aimlessly, in a maze, exhibited considerable learning once some target behavior, such as finding a baited goal box, was reinforced. Similarly, human and animal experiments on overlearning—that is, providing additional learning trials after performance had reached an asymptotic level and was no longer changing—demonstrated that such trials continued to enhance learning, as measured by reduced forgetting or accelerated relearning. More recently, a variety of human memory experiments have shown the converse is true as well: Substantial changes in performance can be accompanied by little or no learning. Massed [Page 243]practice on a task, for example, often leads to rapid gains in performance but little or no effect on learning, as measured by long-term retention or transfer.

Perspective on Learning

That certain difficulties can enhance learning highlights some unique characteristics of how humans learn and remember or fail to learn and remember. We do not store information, for example, by making any kind of literal copy of that information. Rather, we encode and store new information by relating it to what we already know—that is, by mapping it onto, and linking it up with, information that already exists in our memories. New information is stored in terms of its meaning to us, as defined by its relationships to other information in our memories. Storing information, rather than using up memory capacity, creates opportunities for additional storage.

The retrieval processes that characterize human memory are unique, too, and differ markedly from a playback of the type that might characterize a typical recording device. Retrieval of information is inferential and reconstructive rather than literal, and it is also fallible, in part because what is accessible from memory is heavily dependent on current cues, including environmental, interpersonal, body-state, and mood-state cues. In addition, and importantly, the act of retrieving information is itself a potent learning event. Retrieved information, rather than being left in the same state it was in prior to being recalled, becomes more recallable in the future than it would have been otherwise, and competing information associated with the same cues can become less recallable in the future. Using our memories, in effect, alters our memories.

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