Why Your Students Forgot Everything On Your PowerPoint Slides
By Mary Jo Madda (Columnist) Jan 19, 2015
why instructional design doesn’t typically work with students, or anyone’s learning for that matter, when you teach with PowerPoint—as well as how you can avoid it. It all begins with a little concept called “cognitive load.”
Cognitive load describes the capacity of our brain’s working memory (or WM) to hold and process new pieces of information. We’ve all got a limited amount of working memory, so when we have to handle information in more than one way, our load gets heavier, and progressively more challenging to manage.
In a classroom, a student’s cognitive load is greatly affected by the “extraneous” nature of information—in other words, the manner by which information is presented to them (Sweller, 2010). Every teacher instinctively knows there are better—and worse—ways to present information.
A study in Australia in the late 1990s (the 1999 Kalyuga study) compared the learning achievement of a group of college students who watched an educator’s presentation involving a visual text element and an audio text element (meaning there were words on a screen while the teacher also talked) with those who only listened to a lecture, minus the pesky PowerPoint slides.
It’s called the the redundancy effect. Verbal redundancy “arises from the concurrent presentation of text and verbatim speech,” increasing the risk of overloading working memory capacity—and so may have a negative effect on learning.
Researchers including John Sweller and Kimberly Leslie contend that it would be easier for students to learn the differences between herbivores and carnivores by closing their eyes and only listening to the teacher. But students who close their eyes during a lecture are likely to to called out for “failing to paying attention.”
Richard Mayer, a brain scientist at UC Santa Barbara and author of the book Multimedia Learning, offers the following prescription: Eliminate textual elements from presentations and instead talk through points, sharing images or graphs with students
a separate Australian investigation by Leslie et al. (2012), suggest that mixing visual cues with auditory explanations (in math and science classrooms, in particular) are essential and effective. In the Leslie study, a group of 4th grade students who knew nothing about magnetism and light learned significantly more when presented with both images and a teacher’s explanation than a separate group which received only auditory explanation.
- Limit yourself to one word per slide. If you’re defining words, try putting up the vocabulary word and an associated set of images—then challenge students to deduce the definition.
- Honor the “personalization principle,” which essentially says that engaging learners by delivering content in a conversational tone will increase learning. For example, Richard Mayer suggests using lots of “I’s” and “you’s” in your text, as students typically relate better to more informal language.
more on Power Point in this IMS blog