(2007), 481– 498. The standard practice in mathematics textbooks is to cluster practice problems by problem type. This laboratory experiment demonstrated that this standard practice produced inferior per for mance on a fi nal test in which new problems of each problem type were given relative to a practice procedure in which the practice problems from different problem types were shuffl ed (interleaved).
5. The study relating differences in practice strategies to differences in motor- memory consolidation was by S. S. Kantak, K.
J. Sullivan, B. E. Fisher, B. J. Knowlton, & C. J. Winstein, Neural substrates of motor memory consolidation depend on practice structure, Nature Neuroscience 13 (2010), 923– 925.
6. The anagram study was by M. K. Goode, L. Geraci, & H. L.
Roediger, Superiority of variable to repeated practice in transfer on anagram solution, Psychonomic Bulletin & Review 15
(2008), 662– 666. These researchers gave subjects practice on solving anagrams for a set of words: one group was given the same anagram for a par tic u lar target word on every practice
Notes to Pages 54–60 ê 265
trial (massed practice), whereas another group was given a different anagram for a par tic u lar target word on each practice trial (varied practice). Surprisingly, varied practice produced better per for mance on a fi nal trial in which the anagrams were the very ones that were practiced in the other group that had practiced the tested anagram repeatedly.
7. The study about learning of artists’ styles was by N. Kornell & R. A. Bjork, Learning concepts and categories: Is spacing the
“enemy of induction”?, Psychological Science 19 (2008), 585–
592. In these experiments, college students attempted to learn the painting style of a number of relatively unknown artists.
Students learned the styles better when the paintings of the artists were interleaved compared to when each artist’s paintings were massed during learning. Yet, at odds with the objective learning outcomes, most of the learners insisted that they learned better with the massed pre sen ta tions. Another informative study is S. H. K. Kang & H. Pashler, Learning painting styles: Spacing is advantageous when it promotes discriminative contrast, Applied Cognitive Psychology 26 (2012), 97– 103, which showed that mixing the examples of paintings helped to highlight the differences among paint ers’ styles (what we are calling discriminative contrast).
8. The fi nding that improving discrimination among examples contributes to conceptual learning is from L. L. Jacoby, C. N.
Wahlheim, & J. H. Coane, Test- enhanced learning of natural concepts: effects on recognition memory, classifi cation, and metacognition, Journal of Experimental Psychology: Learning, Memory, and Cognition 36 (2010), 1441– 1442.
9. Peter Brown interview of Doulas Larsen, December 23, 2011, St. Louis, MO. All quotes from Larsen are from this interview.
10. Doug Larsen’s work can be found in D. P. Larsen, A. C. Butler, & H. L. Roediger, Repeated testing improves long- term retention relative to repeated study: a randomized controlled trial. Medical Education 43 (2009), 1174– 1181; D. P. Larsen, A. C. Butler, A. L. Lawson, & H. L. Roediger, The importance of seeing the patient: Test- enhanced learning with standardized patients and written tests improves clinical application of knowledge, Advances in Health Science Education 18 (2012), 1– 17; and
Notes to Pages 62–69 ê 266
D. P. Larsen, A. C. Butler, & H. L. Roediger, Comparative effects of test- enhanced learning and self- explanation on long-term retention, Medical Education 47, 7 (2013), 674– 682.
11. Peter Brown interview of Vince Dooley, February 18, 2012, Athens, GA. All quotes of Dooley are from this interview.
12. Psychologists interested in learning have long distinguished between momentary per for mance and underlying learning (as mea sured after a delay with intervening reminders). As a simple example, someone might tell you that James Monroe was the fi fth US president. You would probably be able to answer correctly if asked about the fi fth president for the rest of the day or the week. That would be due to having just heard it (thus boosting the momentary strength or what the psychologists Robert and Elizabeth Bjork call retrieval strength). However, if someone asks you a year later about the fi fth president, this would be a mea sure of habit strength or, as the Bjorks call it, storage strength. See R. A. Bjork & E. L. Bjork, A new theory of disuse and an old theory of stimulus fl uctuation, in A. F.
Healy, S. M. Kosslyn, & R. M. Shiffrin (eds.), From learning pro cesses to cognitive pro cesses: Essays in honor of William K. Estes (vol. 2, pp. 35– 67) (Hillsdale, NJ: Erlbaum, 1992).
For a recent discussion, see N. C. Soderstrom & R. A. Bjork, Learning versus per for mance, in D. S. Dunn (ed.), Oxford Bibliographies online: Psychology (New York: Oxford University Press, 2013) doi 10. 1093/obo/9780199828340-0081.
4. Embrace Diffi culties
1. All quotes of Mia Blundetto are from telephone conversations between Peter Brown, in Austin, TX, and Blundetto, at Camp Fuji, Japan, on February 9 and March 2, 2013.
2. The phrase “desirable diffi culties in learning” originated in the article R. A. Bjork & E. L. Bjork, A new theory of disuse and an old theory of stimulus fl uctuation, in A. F. Healy, S. M.
Kosslyn, & R. M. Shiffrin (eds.), From learning pro cesses to cognitive pro cesses: Essays in honor of William K. Estes (vol.
2, pp. 35– 67) (Hillsdale, NJ: Erlbaum, 1992). The idea seems counterintuitive— how can making a task more diffi cult lead
Notes to Pages 73–78 ê 267
to it’s being learned better and retained longer? The rest of this chapter explains this puzzle and why it seems to arise.
3. Psychologists distinguish among three stages in the learning
/memory pro
cess: Encoding (or acquisition of information); storage (per sis tence of information over time); and retrieval (later use of the information). Any time you successfully remembered an event, all three stages were intact. Forgetting (or the occurrence of false memories— retrieving a wrong “memory” of some event but believing it to be right) can occur at any stage.
4. For a classic article on consolidation, see J. L. McGaugh, Memory— a century of consolidation, Science 287 (2000), 248– 251. For a somewhat more recent and lengthy review, see Y. Dudai, The neurobiology of consolidations, or, how stable is the engram?, Annual Review of Psychology 55 (2004), 51–
86. For evidence that sleep and dreaming helps with memory consolidation, see E. J. Wamsley, M. Tucker, J. D. Payne, J. A.
Benavides, & R. Stickgold, Dreaming of a learning task is associated with enhanced sleep-
dependent memory consolida-
tion, Current Biology 20 (2010), 850– 855.
5. Endel Tulving emphasized the critical role of retrieval cues in remembering by stressing that remembering is always a product of both the information stored (the memory trace) and the cues in the environment that might remind you of the information. With stronger cues, even weaker traces become accessible for recall. See E. Tulving, Cue dependent forgetting, American Scientist 62 (1974), 74– 82.
6. Robert Bjork has emphasized the role of forgetting of an original event to some degree as aiding the amount of learning from a second pre sen ta tion of the same event. The power of spacing of events on memory (the spacing effect) is one example. For examples see N. C. Soderstrom & R. A. Bjork, Learning versus per for mance, in D. S. Dunn (ed.), Oxford Bibliographies in Psychology (New York: Oxford University Press, in press).
7. The problem of old learning interfering with new learning is called negative transfer in psychology. For evidence on how forgetting of old information can help in learning of new
