Difficulties in learning

Are we training people for the short-term or the long-term? Preethi Anand explores the research

Robert Bjork, UCLA professor of Cognitive Psychology, says that certain difficulties experienced by an individual during the learning process, which seemingly impede learning, can actually make the learning experience more effective and can help in long-term retention of the content learnt. Bjork calls them ‘desirable difficulties’.

Participants attending a training programme on advanced concepts, for example, with a well-structured content and simplified instruction, may feel that the learning came to them naturally and their performance during practise exercises in class would also confirm their assumption.

They may even do really well in their level 2 evaluations that test their understanding of the subject. But being able to retrieve learning from short-term memory, as in the above example, does not necessarily mean that the learning would be remembered in the long-term.

Bjork says that having ‘desirable difficulties’ introduced in learning experiences has proven to have considerable impact on the learner’s ability to retain concepts in the long-term, although such learning experiences may appear to be tough on the learner and seem ineffective. 

The science of learning and memory

To understand how the brain learns, we need to know how the brain stores and retrieves new learning. As the common perception goes, we gather information of the world around us through our sensory organs and the brain makes something in the lines of a 5D movie of an event.

If we are more perceptive and attentive, we may remember the movie longer. But in reality storing memories and information and retrieving them are two different, exclusive processes. Now, according to the new theory of disuse (proposed by Bjork), information learnt will always be in our memory.

Every time we relearn the same information, we are adding on to the ‘storage strength’ of that learning; the more times you learn the same thing, the learning stays with you longer.

But ‘retrieval strength’, your ability to quickly retrieve that learning, depends ironically on how frequently you retrieve that learning; the more you use that learning, practise it, the more it will be available to you off the top of your head. And while there is no limit on the storage capacity of the brain, research shows that retrieval strength is limited at any given point of time.

Let us take the example of an employee learning the organisational structure of his company. He will have all the names of all its leaders stored in memory but at a given point of time can remember only a few.  In fact, Bjork says that forgetting plays a huge role in the learning process.

By choosing to forget certain information, we are increasing the retrieval strength of the others. In a training session on computer science, if there are two sessions on Microsoft Excel 2010 and Excel 2003, by telling the participants that they won’t be tested on Excel 2003 (which is redundant), we are increasing the chances of their retrieving information on Excel 2010. Bjork terms this process ‘goal directed forgetting’.

Let us consider the following statements to clarify our understanding of desirable difficulties.

Not all difficulties are desirable

Certain difficulties experienced by an individual during a learning process can potentially hamper learning. If a participant in a training programme is not equipped with the necessary tools and/or a suitable environment to overcome the difficulty, it would become undesirable. Desirable difficulties refer to those difficulties, and those only, that optimise long-term retention and transfer.

Performance during learning does not reflect learning effectiveness

When we simplify the content in a training module and give our participants a specific activity based on the content discussed, the participants may do extremely well. But their performance during training, especially when they do well, can misguide them to think they are well-versed in the subject.

When practising learning, in a classroom setting for example, the participants are drawing only from their short-term memory. While this is better than no practice at all, it may do little to have the learning stored in the long-term, the reason being that participants do not have much time to critically understand the underlying logic in the learning.

Also, most of our practise assignments in the classroom are simplified to such an extent that it does not reflect the real world complexities the participants might have to work with. The participant, observing his performance in the practise exercises, might also mistake his fluency to recall the concepts as a sign of fluency on the subject itself and may be less motivated to pursue learning advanced concepts on the subject.

Desirable difficulties may not be desired by learners

In today’s fast-paced world with immediate results, the word ‘fast track’ has lost its meaning with everything being fast tracked. Learners also would rather have immediate results than those that take time and extra effort, operating under assumptions like reading an idiot’s guide to talent development might make them proficient in the field.

So desirable difficulties might actually not be desired by the learners and by extension the workplace learning professional as well, because any training programme with desirable difficulties plugged into it, would seem ineffective as it would not come to learners naturally, not seem coherent and not show results. But as the saying goes, ‘no pain no gain’.

Desirable difficulties are counterintuitive

For decades, learning functions and educational institutions have believed that simplifying learning experiences could enhance performance. And since the first results of such learning experiences are always positive, it becomes hard for us to go against our gut instinct and introduce difficulties in learning. It would take us some time to get used to this reality, just like it would to adjust to disruptive innovations, but until then we need to go against our instincts.

Methods to introduce desirable difficulties in learning

Varying conditions of learning

Among the common pieces of advice we received as a learner at school, is the classic “find an exclusive place to study for your exams”. Apparently, that is not very effective. By planning our study from different locations, we are actually introducing a desirable difficulty that improves our attention and memory.

The idea is to ensure that the learner does not contextualise learning to a specific location or situation. When you change the physical locations from where you learn, it takes some time for you to get accustomed to that condition and you would put in more effort than normal to overcome this difficulty.

In principle, this is also applicable to the various contexts in which you learn content. Learning the same content from multiple points of view helps in understanding the underlying logic in a theory or a concept and helps in retrieving that memory in all kinds of situations.

For example, when we train people on negotiation strategies, if the practice exercises cover negotiating mergers, acquisitions, negotiating customer deals, negotiating for promotions, negotiating at home etc., the participants are exposed to a number of scenarios in which the same principles of negotiations are applied. And this exposure will help them in effectively handling a completely different context where negotiation is required.

Interleaving content

Consider the study calendar of a student who plans on learning every day instead of cramming on the day before the finals. It will be designed in one of two ways; she will have either planned for one subject a week or one chapter from different subjects every day.

The former is referred to as ‘blocking’ – a study method where subjects are learnt in one whole block at a time. The latter is referred to as ‘interleaving’ – where subjects are interleaved with other non-related blocks when learning. Our natural instinct would say that blocking is more effective than interleaving, but interleaving – another powerful desirable difficulty – has proven to be more effective in a vast majority of scenarios.

In an interesting experiment conducted by Bjork and Kernell in 2008, two groups of participants were shown a series of paintings to learn about painting styles of famous painters. One group was exposed to the paintings of only one artist whom they studied (blocking) while the other group was exposed to paintings of a few more artists as well (interleaving).

When assessed, the group whose learning contents were interleaved fared better than the other. Experiments in this area have revealed that while blocking helps identifying common concepts and characteristics of a subject learnt, interleaving helps learners differentiate the unique concepts and characteristics from others.

Distributing or spacing learning

In the early years of my career, I curiously waited for my participants’ reaction when a break is announced; the dreaded sigh of relief often made my heart sink no matter how warranted that break was. But that space to breathe between training, we have seen, actually helps improve the learning, just as an employees’ performance improves after a vacation.

Bjork refers to ‘spacing’ as a desirable difficulty because planned spaces between learning events pushes a learner to recall a concept that isn’t at the top of their mind and that difficulty helps retain that learning for longer.

It is not just spaces between learning that is significant, but spaced retrieval practise also help learners consistently bring forgotten learning to the top of their mind and increase the retrieval strength of the content learnt. It is also said that in spacing, a learner may not remember all characteristics of a few materials for example, but will know the gist of the content learnt. Spacing thus promotes abstraction.


“Give a man a fish, and you feed him for a day; show him how to catch fish, and you feed him for a lifetime.” This often quoted proverb’s manifestation can be seen in the desirable difficulty of ‘generation.’

When learning is a presentation of ideas, the learner becomes a passive absorber of information. Instead, when the necessity for the idea is presented and learners are guided to arrive at a solution, the learner puts in considerable mental effort to generate that idea. Though a difficulty, this generation rather than the passive consumption of knowledge has a greater storage as well as retrieval strength.


While most of us want to make things straightforward for our learners this research clearly shows that introducing ‘difficulty’ or ‘variation’ in learning can ensure a greater learning outcome. Understanding ‘how’ we learn is increasingly as important as ‘what’ we learn.


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