A tennis player might practice her forehand before building up to a backhand—mastering skills in isolation makes sense, and sequencing them from easiest to more difficult is a tried-and-true strategy. Eventually, though, alternating forehands with backhands and volleys makes for a more adaptable, flexible player.
Similarly, when we give students opportunities to work through combinations of related ideas and concepts—a technique called interleaving—instead of limiting them to a one-skill-at-a-time approach, it allows them to store information more deeply, challenging them to tease out patterns and form connections. It’s a practice that’s gaining attention among educators, writes teacher Larry Ferlazzo, who recently asked several educators to write about interleaving for his “Classroom Q&A” blog on Education Week.
“Many of us were taught that dogged, singularly focused practice is the way to mastery, and our belief in this runs deep,” writes Meg Riordan, chief learning officer for the after-school program The Possible Project, in the blog. “But research indicates that gains during interleaving promote longer-term skill development and retention, plus more seamless transfer to other contexts.”
With interleaving, students learn by tackling a mix of related concepts, forcing the brain to work hard to recall prior learning and determine which strategies or skills to use to solve them. It’s demanding work that helps make “long-term memory solid, problem solving easier, and mastery improve,” notes education consultant Margaret Searle. However, it’s not a replacement for traditional blocked practice work, Searle cautions. Massed practice remains an important component of initial learning, but interleaving can be especially valuable when used at strategic intervals to solidify deeper learning.
Here are a few strategies for teachers to consider when using interleaving in the classroom.
Because massed practice tends to be associated with learning in sequential chunks—first addition, then subtraction, multiplication, and division, for example—students are typically able to tackle a large number of problems at one time, relying on muscle memory and rote practice.
A student studying multiplication, for instance, might work through a 30-question multiplication worksheet at a relatively quick pace. But when teachers mix up different combinations of concepts, the learning tasks become more intellectually taxing and time-consuming, requiring kids to slow down and mentally toggle through lots of information, making connections in their thinking before arriving at the appropriate strategies to solve a problem.
In order for interleaving to appropriately challenge students but not overwhelm them, Riordan says it’s important to select fewer interleaved practice problems for students to tackle at one time—providing opportunities for them to work deeply rather than quickly. “Interleaving doesn’t mean dismissing the fundamentals or never employing blocked practice,” she clarifies. “Instead, it means avoiding the kind of massed practice that creates thoughtless repetition.”
A station rotation model can provide an engaging framework for trying out interleaving, allowing students to rotate quickly through different related concepts in small groups—scaffolded with a mix of teacher-led instruction, online learning, and collaborative activities.
Try introducing “several related concepts at an introductory level and then engage learners in practicing these various concepts,” at different stations, Riordan suggests. When students are studying volumetric problems related to cones, pyramids, cubes, and spheres, for example, set up a station rotation so they can practice working through a rich mix of varied problems. It’s a creative way to get kids recalling previous knowledge and applying it in unexpected ways, Riordan adds, ultimately “improving learning and increasing long-term proficiency.”
In a volleyball game, players don’t just face a constant stream of spikes; they face spikes, sets, blocks, passes, serves, and digs, writes Riordan. Similarly, in an engaging project, students often practice a myriad of skills, including design thinking, prototyping ideas, and problem-solving.
With interleaving, “subjects, topics, disciplines, even levels of mastery can all be stirred together to create an end project that’s pretty awesome,” writes Jen Schwanke, a former elementary and middle school teacher and administrator. “This is why I love project-based learning. It’s why I love units with multiple, varying, dynamic opportunities for students. It’s why I love choice and giving students the opportunity to showcase their learning in unique ways.”
When planning units, try incorporating activities that integrate a variety of concepts—both old and new—to help students refresh their memories, understand the materials in the context of related ideas, and extend their learning. “Students experience the world in an interleaving manner, so it follows that they learn best in a similar way,” writes Riordan.
And when wrapping up a unit, “do not let students completely move on from previous learning,” writes Rishi Sriram, an associate professor at Baylor University’s School of Education. To help students strengthen their long-term memory, Sriram suggests setting aside a few moments each day to review previous concepts and including some questions from past lessons on current tests, weaving a web of knowledge and connections. When teachers offer students challenging tasks like mixed practice, it encourages the type of productive struggle that results in better learning. “Students will make more mistakes, but these mistakes are productive because they build better roads in their brains."