The guru of multimedia learning Richard Mayer has just published a new paper that all presenters should take note of. The paper is called “Increased interestingness of extraneous details in a multimedia science presentation leads to decreased learning”.
Students received one of two PowerPoint presentations about how a cold virus infects the human body.
Both PowerPoint presentations included interesting but irrelevant details about viruses. In the first presentation the details were of high-interest eg: the role of viruses in sex and death. In the second presentation the details were of low-interest eg: health tips about viruses.
Note that these details are topically relevant (eg: related to the topic of viruses) but not conceptually relevant (eg: related to the explanation of how viruses infect the human body).
The research studied how well students did on both retention (how much they remember) and understanding (how well they can apply what they have learnt).
The students who received the second presentation (low-interest details) did much better on tests that measured understanding. However retention was not significantly different between the two groups. So as the interestingness of details increased, understanding decreased. Mayer concludes:
Results are consistent with a cognitive theory of multimedia learning, in which highly interesting details sap processing capacity away from deeper cognitive processing of the core material during learning.
Two competing theories
This research further supports the cognitive theory of multimedia learning.
But most presentation books and blogs are enthrall to arousal theory: the idea that people learn better when they are emotionally aroused by information (for references see Multimedia Learning). Therefore they emphasise telling stories as a way of emotionally engaging the audience. But Mayer says in Multimedia Learning:
In spite of its commonsense approach, arousal theory is based on an outmoded view of learning as information acquisition – the idea that learning involves taking information from the teacher and putting it into the learner. In contrast, the cognitive theory of multimedia learning is based on the view of learning as knowledge construction – the idea that learners actively build mental representations based on what is presented and what they already know. It follows that seductive details may interfere with the process of knowledge construction.
What does this mean for you and your presentation?
Don’t include a story that is interesting and emotionally engaging but not 100% conceptually relevant. Though in the short-term you’ll keep the attention of your audience, it will sacrifice focus and understanding of your core message.