A desirable difficulty is a learning task that requires a considerable but desirable amount of effort, thereby improving long-term performance. It is also described as a learning level achieved through a sequence of learning tasks and feedback that lead to enhanced learning and transfer.
As the name suggests, desirable difficulties should be highly desirable and increasingly challenging. Research suggests that while difficult tasks might slow down learning initially, the long-term benefits are greater than with easy tasks. However, to be desirable, the tasks must also be achievable.
Background
Many tasks give the illusion of learning because they are easily completed. For example, re-reading notes or a textbook is a common learning tactic that has been proven to be less beneficial than using flashcards. A student may feel like they are learning while re-reading due to the fact that the words are more familiar during the second or third read. However, this does not mean that the material is being processed, internalized, and learned as they may believe. Flashcards on the other hand, require the student to actively recall the information. This is a desirable difficulty because it requires more effort and forces the student to do more complex processing. At first, learning with desirable difficulties may take longer and the student may not feel as confident, but over time knowledge will be retained better.
The term was first coined by Robert A. Bjork in 1994. The UCLA psychologist introduced the concept as an experience that makes learning more difficult, allowing students to form stronger connections. The idea is that, as the task difficulty increases, learning also increases due to the way it challenges the learner to achieve his optimum performance.
Requirements
To determine whether a difficulty is desirable, use the following three guidelines: The processing at encoding should be the same as the processing at retrieval. The processing at encoding should be the same as the processing during practice. The task must be able to be accomplished. Too difficult a task may dissuade the learner and prevent full processing.
A model called the Challenge Point Framework can also be used. It is based on the relationship between task difficulty and the ability or the knowledge and skills of the learner. This framework identifies the so-called Optimal Challenge Point (OCP), where the learner obtains the greatest potential for learning.
Research and examples
Researchers have experimented with various methods of learning. A common theme between the methods that have proven to be most beneficial is that they all present difficulties and challenges to the learner. Compared with traditional easier learning methods, they appear to make learning slower. The traditional easy tasks often show better temporary performance effects, and these are confused for more permanent effects. While this is somewhat counterintuitive, studies show that difficulties are better for increased performance in the long run. The following are examples of training tasks that are desirably difficult.
Retrieval practice
Also known as the testing effect, retrieval practice uses testing as a training tactic. Performance can be improved by devoting some of the learning period to testing by trying to recall the to-be-learned information. An example of this is flashcards, where a student will try to answer what is on the back of a card based on what is written on the front of a card (i.e. a word on the front and its definition on the back). One study found that increasing the pile of flashcards to study at one time, and thereby increasing the difficulty, caused students to perform better on their tests. For best results, feedback is key; the learner should receive feedback on their performance and learn the correct answers.
Delayed feedback
To improve, students need to receive feedback on their work; feedback could consist of the correct answers, a grade, comments, etc. While feedback is essential, a surprising result found is that delaying feedback is better than receiving immediate feedback. This is contingent on the delayed feedback being guaranteed. Notably, this claim is highly improbable, and is inconsistent with a wealth of research highlighting the benefits of immediate feedback. Feedback in any form is better than no feedback at all.
Some experts note that, presently, the mechanisms that can precisely cause desirable difficulty effect are not yet well understood.