Desirable Difficulties

After 13 years of K-12 education (and many more beyond that if you are anything like me), you’d think that we’d all be experts in how to learn. But it turns out that we’ve all likely wasted many hours studying with subpar learning techniques. Approximately 80% of people have never been specifically taught how to study, and for those who have been taught specific strategies, most rely on intuition rather than empirical research (Kornell & Bjork, 2007). In fact, many teachers endorse ideas about learning that are not supported by the research community (Morehead, Rhodes, & DeLozier, 2016).

A key distinction many fail to recognize is the difference between current performance and learning. If, for example, you cram for an exam the night before, dump everything you studied out, get a good grade, and move along, you are demonstrating immediate performance with the materials. A better measure of how much you learned is demonstrated by how much of that information you’d be able to remember on a surprise pop quiz a few weeks later.It turns out that many of the strategies that support immediate performance do not support lasting learning (Soderstrom & Bjork, 2013). Research shows that activities that appear to impair initial performance and thus may feel counterintuitive to learners, support long-term and flexible learning. These activities, a few of which are discussed below, are known as "desirable difficulties" (Bjork, 1994).

Before an exam, many students will simply reread textbook chapters or review their notes. While these activities feel useful, only incremental gains in learning occur relative to the amount of time spent. A more productive use of time would be to engage in retrieval practice. Research shows that repeated retrieval of studied information increases long-term retention of information (Roediger & Karpicke, 2006). Taking practice tests or answering practice questions are thus learning opportunities in addition to assessing how well something has been learned. Not being given questions, however, does not preclude retrieval practice. Simply covering up areas of text and trying to recall that information is an easy way to engage in retrieval practice.

Think back to your days of learning math. Your teacher probably spent an entire class period going over one type of problem. Then you went home that night and completed a homework sheet, practicing that type of problem until you could do it without really even thinking.Just because someone appears to demonstrate mastery on a homework sheet the day of learning does not mean that this learning will stick. A better approach for long-term success, is to interleave or mix up different problem types. While it may initially seem that learning is being slowed, shuffling the problem types requires discriminating between different types of problems which enhances learning as assessed by a later test (Rohrer & Taylor, 2007).

Another area of research involves the metacognitive aspects of "desirable difficulties" and their incorporation into self-regulated studying. Many of the above findings are in direct contrast to what learners feel is best for their learning. For example, in an inductive learning task where the goal is to learn the painting styles of various artists, interleaving paintings from different artists overwhelmingly enhances learning relative to blocking the paintings. Individuals, however, largely feel that blocking is a better study strategy (Kornell & Bjork, 2008). How to overcome these metacognitive deficits remains an important area of continued research.

For more even more information on "desirable difficulties," please visit the Bjork Lab website.