PowerPoint presentations have achieved a reputation for leaving their audiences more confused than when they started, but that hasn't hindered their widespread adoption in the business and academic worlds. That may not be an entirely bad thing, as a poor presenter can screw up in almost any medium, while some studies have suggested that presentation software can be a more effective teaching tool than things like overhead projections. What hasn't been clear is whether all the capabilities provided by presentation software are useful and, if so, whether they are being used in a way that's conducive to learning. A study in the International Journal of Innovation and Learning has now looked into how animations influence student comprehension, and suggests that they should be used cautiously.

Animations can be used in a variety of contexts within a presentation, but one of the most common is to simply control the rate at which information appears to students. So, for example, on a slide dedicated to discussing four aspects of a given topic, the relevant text and images can be made to appear gradually, so that each aspect is discussed thoroughly before the next even appears. The alternative, dumping all the information to the screen at once, and then working through it verbally, would seem to have the potential to distract and overwhelm the audience. So, this seems to be a situation where animation should clearly help.

Seems turns out to be the key word in that sentence, at least according to the study. The authors created a single PowerPoint presentation, and then eliminated the animations from it (on average, there were 3.4 animations per slide). They then recorded a single sound track and synched it to both presentations, so that the class would be identical except for the animations. Five weeks before the experiment, the class was given a quiz on the topic to provide a baseline assessment of knowledge on the topic (which was information security and privacy issues); the quiz was given a second time following the presentation.

Both presentations dramatically improved the students' scores, which were a bit below 40 percent correct in the first administration of the quiz. But the animated presentation brought scores up to 71 percent, while the animation-free version got them to 82 percent. Of the nine questions, only one saw the animated group outperform their static peers.

This isn't a complete shock, as the authors cite a study that indicated that presentations containing irrelevant pictures or sounds (we're looking at you, corporate PowerPoint templates) can also decrease student comprehension. The surprise is that animations that are intended to increase focus can be just as distracting. Note the "can" in that sentence, however—the differences between the scores of the two groups ranged from insignificant to nearly 25 percent, so it's clear that animation isn't uniformly harmful to learning, a point the authors themselves note in the discussion.

The problem, they suggest, is that PowerPoint made its way into the classroom well in advance of our understanding of how best to use it. The authors point out that we've actually got a well elaborated set of theories of learning, meaning we understand how children absorb and integrate knowledge, and we can use that to help determine how best to teach. But the early technology adopters aren't always the ones who understand educational approaches, so we tend to have to clean up messes after the fact. Another recent discussion of technology in education pointed out that we've now reached the point where a lot of instructional material is visual, but our tests are still static, text-based affairs, and the mismatch might help explain some of these results.

In a class I taught several years ago, I'd initially relied on animations to explain a temporal process in which a collection of proteins gradually assembled to perform a task. But I gradually realized that the students were downloading the PDF of my lecture and printing it to use for study aid—again, the static-animation mismatch was causing more problems than the animation solved during the lecture, and I gradually changed my approach.

In the end, part of what the study points out is what should be obvious for anyone doing a presentation: think carefully about what you're doing, and make sure it doesn't have anything extraneous to the task at hand. The real surprise is that the control of information through animations may be extraneous in many contexts.

International Journal of Innovation and Learning, 2009. DOI not yet available.