- Blog post
‘Desirable difficulties’: Too easy accelerates Forgetting Curve
If you’re getting high evaluations but low long-term learning retention rates, consider looking at how challenging the training was.
Training that includes “desirable difficulties” – obstacles that force trainees to put in more effort – may be less popular but more effective than fun-and-easy lessons.
Here’s a cautionary example: An online tutorial garnered high praise from 92% of participants. An immediate post-test showed average scores of 76%, compared to the pre-test average score of 50%. So far, so good. Any trainer would be proud of those results.
Problem was, researchers found that the score gains halved within eight days. And there was NO significant retention after 55 days. Nothing. As if they never took the tutorial.
The researchers compared their results to an earlier study they’d completed: A similar group of professionals retained 40% of their initial knowledge gains from training.
Researchers looked at what they’d done differently, and found this: They’d integrated some of the negative feedback from the earlier study to make the subsequent tutorial easier.
“In retrospect, we may have removed some of the ‘desirable difficulties’ – aspects that make initial knowledge acquisition more difficult and less appealing, but enhances long-term retention,” they stated.
Bottom line: Learning that’s easily acquired is easily lost.
Here are some ways to incorporate “desirable difficulties” in your training:
1. Create unpredictability
Researchers have found that long-term performance is enhanced by introducing variation or unpredictability into your training.
For example, when you’re teaching a new skill, the logical thing is to teach the skill, have people practice it until they master it, and then move on.
Bad idea, the research says. Instead, schedule practice sessions to occur randomly after the training sessions.
Some sessions might happen soon after the training, but others might occur days or weeks later, without warning.
People will do worse in these later sessions, but in the long run they’ll learn more.
2. Change the task
Another way to create unpredictability: Change up the “task parameters” for follow-up events.
If you were coaching pitchers on how to throw a curve ball, for example, you’d want them to practice with right-handed hitters, left-handed hitters, tall hitters and short hitters.
When you’re training, throw a few curve balls of your own. Let’s say you’re teaching managers how to get buy-in for a new initiative. In follow-up role plays, introduce new objections that you didn’t explicitly cover in the training.
Trainees will have to work harder – and that will help the learning stick.
Or you might ask salespeople to consider a new sales technique from a buyer’s perspective. Ask how they’d react as a buyer to the technique.
Multiple retrieval formats have similar effects. Don’t just rely on quizzes or role plays. Use a variety of techniques.
3. Create interference
Of course you want your training to flow smoothly, in an orderly and logical fashion, with no detours or interruptions along the way. Right?
Wrong, researchers say. “Contextual interference” enhances retention.
In one experiment, for example, students were asked to study a technical article. Some received an outline that followed the same organization as the article. Others received an outline that covered the same material, but was organized differently. The second group did better.
Another way to create interference: Don’t cover everything at once. Train people the way they learned in high school. They don’t get English on Monday and math on Tuesday. They get a little at a time, interrupted by other stuff.
Yes, multiple sessions are inconvenient for trainers and trainees alike. But they work better.
4. Don’t help so much
Everyone knows how important feedback is to learning. But less may be better than more.
When you provide a lot of feedback, learners acquire skills and knowledge quickly. When you limit your feedback, they struggle more – but learn better.
For example, one study found that providing feedback after every 5 or 15 trials is more effective in the long term than providing feedback after every trial.
Bell, D., et al. (2008). Knowledge retention after an online tutorial. J Gen Intern Med, 23, 1164-71.
Bjork R.A. (1994). Memory and metamemory considerations in the training of human beings. In Metcalfe J and Shimamura (eds.), Metacognition: Knowing about knowing, pp. 195-205. MIT Press.