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Research School Network: Bjork’s Desirable Difficulties A look into the ways that teachers can create desirable diffculties in their teaching, based on the work of Robert Bjork


Bjork’s Desirable Difficulties

A look into the ways that teachers can create desirable diffculties in their teaching, based on the work of Robert Bjork

by Durrington Research School
on the

When it comes to the concept of desirable difficulties” there is only one place or person to turn to – Professor Robert Bjork. Bjork first introduced the term in his seminal 1994 work, and since he and Elizabeth Bjork have produced various pieces of follow up work further examining the theory. The theory is based within Bjork’s concerns that many students believe memory works like a tape or video” recorder, with repeated exposure to the same material enabling it to be written into their memory. Such a belief means that students often engage in learning strategies that involve re-exposing themselves to the same material, in the false belief that this will result in effective learning. 

Students can often misjudge their understanding and comprehension due to the subjective impression that can be created when re-reading notes, as it creates a sense of perceptual fluency that can be misinterpreted as understanding. Furthermore students can often recall information quickly due to environmental cues, for example those in their study area, creating further sense of fluency that is unlikely to be sustained. The issue is that these perceptual fluencies create a nice” feeling for our students, and such practices often create observable and measurable performance gains that led to our students misinterpreting their learning. Unfortunately conditions that lend themselves to rapid performance gains, often fail to support long term retention, whereas the conditions that do, seem to create challenges and slow the rate of apparent learning, thus making them uncomfortable and unpopular with many students. It is these uncomfortable, but necessary challenges that Bjork deems to be the desirable difficulties”.

Bjork goes to great lengths to explain that this does not mean we should make everything we teach more difficult. He admits that many difficulties students are confronted with when learning our undesirable, and that students must have a degree of background knowledge with which to overcome any desirable difficulties embedded into the learning progress. Desirable difficulties trigger encoding and retrieval processes that support learning, and include things such as varying the conditions of learning, interleaving instruction, spaced practice and testing.

1. Varying practice:

Bjork argues that instruction under predictable conditions, can lead to learning to become contextualised. As a result material can be easily retrieved in the context of the learning, but such predictability does not support delayed performance or tests in different contexts. Research has indicated that increasing variability within instruction strategies increases long term and out of context recall. Research has shown that even teaching the same material twice in different rooms, compared to the same room, can have positive impacts on recall. While logistically, moving rooms is not realistic (nor is this blog suggesting it) and there are arguments for having a degree of regularity in lessons, Bjork’ summary of the research does suggest that a certain amount of variability in regards to instruction strategy and task processes can have positive impacts.

2. Spacing Study or Practice Sessions

There is much research on the positive effects of distributed practice and study. While mass practice can support shot term performance (i.e. cramming for exams), the consensus is that spacing practice supports long term retention due to the intrinsic difficulty created by recalling information from the long term memory. The act of recalling distance information, while not as enjoyable as quickly retrieving recently taught information, is also linked to increasing our storage strength” and therefore reduce the rate of forgetting.

3. Interleaving v Blocking:

Blocking much like mass practice creates seemingly rapid gains in apparent performance, but produces minimal impacts in regards to sustained learning. Superior long term retention and transfer of skills was attributed to interleaved practice, for example when participants were asked to learn volume formulas for various 3D shapes, interleaving instruction enhanced performance on delayed test a week later, with the interleaving group achieving 63% of problem correct versus 20% for their block taught groups. Returning to our original problem, blocking creates an un-useful feeling of learning, that makes it popular with students, while the challenge of planning an interleaved curriculum means it is often avoided by curriculum planners. For more information of interleaving please read here.

4. Generation Effect and Using Tests:

A wealth of studies have indicated the benefits for long term retention of generating an answer, solution or procedure versus being presented with the answer or solution. In such situations students are robbed of the opportunity to confront a desirable difficulty and therefore a powerful learning opportunity. It must be noted that expecting students to generate an answer without the requisite back ground knowledge/​context is an example of an undesirable difficulty and will result in little to no learning and the potential for misconceptions to develop.

Like the generation effect, there is a large body of research demonstrating the power of tests as learning events. Please read here for more information on the testing effect. Despite its evidential benefits, the effectiveness of tests as a learning event remains largely underappreciated, partly due testing being viewed as vehicle of assessment rather than learning.

Testing can also have metacognitive benefits. By creating desirable difficulties, testing supports students in identifying whether information has or has not been understood/​learned, in a way that simply re-learning material will not achieve. Such identification supports students in becoming self-regulating learners, and is likely to lead to more effective long term learning.

If you want to find out more about the use of self testing, why not book onto our twilight CPD here.

Further Reading:

Elizabeth L. Bjork and Robert Bjork: Making Things Hard on Yourself, But in a Good Way: Creating Desirable Difficulties to Enhance Learning

Robert Bjork: Memory and Metamemory considerations in the training of human beings. In J. Metcalfe and A. Shimamura (Eds.), Metacognition: Knowing about knowing (pp. 185 – 205). 

Further Watching:

A 4‑minute video with Robert Bjork explaining the his thinking behind the concept of desirable difficulties” – 

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