Imagine that you are an art student tasked with learning the painting styles of 12 different landscape artists by studying examples of their paintings — so that when you are shown new paintings by the studied artists you will be able to identify the artist responsible for each new painting. Imagine further that you will get to study the paintings one at a time, but have to choose between studying the paintings one artist at a time (i.e., blocked by artist), or with paintings by different artists mixed together (i.e., interleaved). Which study schedule would you choose, blocked or interleaved?
Like most people, you would probably choose the blocked schedule, but recent findings have demonstrated that interleaving — not blocking — the exemplars of to-be-learned categories, such as artists' styles, species of butterflies, families of birds, mathematics, or categories of novel objects, enhances such inductive learning.
However, even after taking a final test on which interleaving led to better classification performance, participants tend to say the opposite: Nearly 80% of the participants in Kornell and Bjork's (2008) experiment thought blocking had been as good or better for learning than interleaving. Additionally, when Tauber, Dunlosky, Rawson, Wahlheim, and Jacoby (2012) allowed participants to choose the order in which to see different exemplars of the to-be-learned families of birds, the participants overwhelmingly chose to block their study.
In the featured article published in the Journal of Experimental Psychology: General, Yan, Bjork, and Bjork (2016) (PDF, 434KB) set out to examine why the illusion that blocking enhances inductive learning is so compelling and to explore what information or experiences might lead participants to understand the benefits of interleaving. The participants' faith in blocking proved remarkably difficult to dislodge.
- When the researchers attempted to alert participants to the link between study schedule and test performance by asking them, on the final test, whether the artist responsible for the painting had been in the blocked or interleaved condition, the participants, rather than coming to realize the benefits of interleaving, appeared to use the heuristic, "If I was wrong on this artist, the correct artist's paintings must have been interleaved."
- When the researchers told participants (after they had studied some artists' paintings blocked and other artists' paintings interleaved) that "90% of participants learn better with interleaving," a clear majority of the participants still said that blocking helped them learn better — that is, they said they were in the other 10%.
- When the researchers told participants how they actually had done in identifying new paintings by artists they had studied interleaved or blocked and then asked them why, the small number of participants who did better on the blocked artists tended to attribute their performance to blocking being a more effective schedule, whereas the participants who did better on the interleaved artists (the majority) tended to attribute their performance to the interleaved artists being easier to learn.
- Even after receiving feedback about their own test performance, about half of those whose own test performance showed an interleaving benefit still said that they would use a blocked schedule to teach hypothetical students.
In fact, it required very explicit separation of blocked and interleaved study-test experiences to get a majority of participants to acknowledge that interleaving was superior to blocking.
Why is the illusion that blocking enhances inductive learning so difficult to dislodge?
One factor is that blocking creates a sense of fluent identification of the features that are shared by the exemplars of a given category or concept, whereas interleaving creates a sense of difficulty and confusion.
Another possible factor is that participants may come to such experiments with a pre-existing belief that blocking is better, given the likelihood that their prior instructors — in both school and training contexts, such as sports training — tended to block instruction by topic or skill component.
And, finally, why are these findings important?
Learning is increasingly self-regulated, and not falling prey to illusions of learning is an important component of becoming an effective learner. Knowing how to learn has always been important, but never more so than in our complex world, and not simply during our years of formal schooling, but also across our lifetimes as careers, job-demands, and technologies change.
Citation:
- Yan, V. X., Bjork, E. L., & Bjork, R. A. (2016). On the difficulty of mending metacognitive illusions: A priori theories, fluency effects, and misattributions of the interleaving benefit. Journal of Experimental Psychology: General, 145(7), 918–933. http://dx.doi.org/10.1037/xge0000177
Note: This article is in the Basic / Experimental Psychology topic area. View more articles in the Basic / Experimental Psychology topic area.