Desirable Difficulties

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Why it works

One of the most counterintuitive and important findings in the science of learning, associated above all with Robert and Elizabeth Bjork, is that the conditions which make learning feel easy and fluent in the moment are often the ones that produce the weakest long-term learning, while certain difficulties, introduced deliberately, strengthen it. The Bjorks call these desirable difficulties: challenges that slow acquisition and make performance during practice look worse, but that enhance retention and transfer. The classic examples are the engines of effective practice. Spacing practice out over time (rather than massing it in one block) makes each session feel harder because some forgetting has occurred, but that very effort of retrieval after a delay strengthens memory far more than cramming. Retrieval practice, recalling information from memory rather than rereading it, feels more effortful and error-prone than review, but it builds durable learning that rereading does not. Interleaving different problem types (rather than blocking one type at a time) makes practice feel confusing and performance drop, because learners must repeatedly discriminate which approach to use, but it dramatically improves the ability to choose the right strategy later. Varying the conditions of practice feels less smooth than repeating identical conditions, but it builds flexible, transferable skill. The deep point uniting them is a distinction between current performance and durable learning: how well a student performs during practice is a poor and often misleading indicator of how much they are actually learning, because the smooth, confident performance that easy practice produces can mask shallow learning that evaporates, while the halting, error-filled performance that desirable difficulties produce can signal deep learning taking hold. This matters enormously for teaching, because the pull toward fluency is strong and goes in the wrong direction. Students prefer easy practice because it feels productive and confirms competence; teachers are drawn to it because the room looks successful and students are not frustrated; and both mistake the comfortable feeling of fluency for learning. Teaching against this means designing practice that embraces productive difficulty, spacing, retrieving, interleaving, varying, while also helping students understand why the harder path works, so they do not interpret the struggle as failure or bad teaching. The difficulties must be desirable, not merely hard: challenges the learner can overcome with effort, not ones that exceed their capacity. The workshop helps teachers see the performance-versus-learning distinction, recognize where their practice is too smooth, and redesign it to include the right difficulties.

The research: Bjork, R. A. & Bjork, E. L. Making Things Hard on Yourself, But in a Good Way.

The run-of-show

Choose your slot. The agenda, timings, and length update to match.

The core activity: design practice for productive difficulty

The heart of the session is spotting where practice is too smooth and redesigning it to include the right difficulties.

Grasp the key distinction: current performance during practice is a poor, often misleading, indicator of durable learning.
Use the desirable difficulties: space practice over time, use retrieval instead of rereading, interleave problem types, and vary conditions.
Resist the pull of fluency: easy practice feels productive to students and teachers but can mask shallow learning that evaporates.
Keep difficulties desirable, not merely hard, challenges the learner can overcome with effort, and explain to students why the harder path works.

Harder in the moment, stronger for the long termThe smooth, easy practice that feels most effective is often the least. Design in spacing, retrieval, interleaving, and variation, and help students see that the struggle is the learning, not a sign of failure.

Facilitator notes

Performance is not learning; the comfortable fluency of easy practice masks shallow learning that fades.
Make difficulties desirable, not overwhelming; the challenge must be within reach with effort, or it just frustrates.
Explain the rationale to students; without it, they read the harder path as bad teaching rather than better learning.

Both students and teachers are pulled the wrong wayStudents prefer easy practice because it confirms competence; teachers like a room that looks successful. Both mistake fluency for learning, which is why designing in difficulty takes intention.

Adapt it

Elementary: build in spaced review and low-stakes retrieval; keep the difficulty achievable and framed positively.
Secondary: interleave problem types and vary conditions so students learn to choose strategies, not just execute them.
Any setting: tell students why practice feels harder; the rationale keeps struggle from reading as failure.

Participant handout

One page for every teacher. Print it, or save it as a PDF.

K12 Academics · Professional Learning

Desirable Difficulties: harder now, stronger later

Design for productive difficulty: use spacing, retrieval, interleaving, and variation, and help students see that the struggle is the learning.

Where my practice is too smooth and fluent:
A desirable difficulty I will add (spacing, retrieval, interleaving, variation):
How I keep it desirable, not overwhelming:
How I explain to students why the harder path works:
How I avoid mistaking performance for learning:

Make it stick

Difficulty pays off over time, not in the moment. Close by setting the follow-up:

Name a check-in: did the added difficulty improve later retention and transfer?
Bring one practice you redesigned and how students responded.
Keep resisting the pull of fluency; comfortable practice is the warning sign.

Common questions

Isn't making learning harder just going to frustrate and discourage students?

Only if the difficulty is the wrong kind. The Bjorks are precise that the difficulties must be desirable: challenges a learner can overcome with reasonable effort, not ones that exceed their capacity, which would indeed just frustrate. Spacing, retrieval, interleaving, and variation increase the effort of learning without putting the material out of reach. The other half of the answer is to help students understand why the harder path works, because a student who knows that effortful, error-prone practice is building durable learning reads the struggle very differently from one who thinks it means they are failing. Framed and pitched well, productive difficulty tends to build confidence over time, as students see their durable learning hold up.

If easy practice feels so effective, how do I know it isn't working?

By distinguishing performance during practice from durable learning afterward, which is the central insight. Easy, massed, re-reading-style practice produces smooth performance in the moment, which feels like success and is why both students and teachers are drawn to it, but that fluency often masks shallow learning that fades quickly once the practice stops. The real test is delayed: how much students retain and can transfer days or weeks later, not how well they perform right now. When you measure learning after a delay rather than judging it by in-the-moment smoothness, the practices that felt harder (spacing, retrieval, interleaving) reliably outperform the ones that felt effortless, which is exactly the counterintuitive finding.

Aren't desirable difficulties just the same as retrieval practice and spacing I already know about?

Spacing, retrieval, and interleaving are specific desirable difficulties, so there is real overlap, but desirable difficulties is the broader principle that unites and explains them, and that is worth grasping in its own right. The unifying idea, that difficulties which slow performance in the moment can strengthen long-term learning, tells you why those specific techniques work and gives you a lens for evaluating any practice design, including ones not on the standard list, such as varying the conditions of practice. Understanding the principle also guards against the common mistake of treating the techniques as isolated tricks; it keeps the focus on the real goal, durable learning over fluent performance, which is what makes the individual strategies make sense.