The Haversian Canal

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September 21, 2006

Why PowerPoint Is Bad and What to Do About It

PowerPoint is antithetical to the one thing students need from professors: schema. PowerPoint shatters the professor's schema that they are trying to present to the students. It causes students to tear down large amounts of knowledge and attempt to rebuild the information because the information is fragmented and it becomes exceedingly inefficient to try to rebuild whole from the pieces. This destruction of schema is very bad for education, but very good for advertizing.

PowerPoint breaks up the framework for knowledge. Diagrams, outlines, paragraphs, these are the shapes of knowledge and they rarely take the form a computer screen, and those subject-oriented shapes are usually too dense, require to much real estate to fit on a single PowerPoint slide that is readable from the back of the room. Indeed, there's a running recommendation that presenters and lecturers should plan about one slide every two minutes, or about 25 slides for a fifty minute lecture, and this is about what we see, at least at my school, but also in my past jobs, and other schools where I have sat in on classes. These frameworks for knowledge are called schemas. The physical representation of our knowledge is the architecture of the synapses between neurons, and the location of neurons, in the brain. So too, learning is the the formation of new synapses, and nueral pruning.

Not only does PowerPoint fragment the shema spatially and temporally, it can actually tear down the student's partially built schema, by undermining the confidence the student has in their sources. Loss of confidence is a terrible thing. To illustrate this, think about what the phrase 'loss of confidence' means to a military commander in the field. If a commander looses confidence in a subordinate commander, they have to relieve that subordinate of their duties! The commander will decapitate on of their own units to remove that one person who lost their confidence! Similarly, a student who looses confidence in an element of material may feel the need to tear down a whole wall of knowledge and rebuild it if they loose confidence in it. This becomes a wildly inefficient use of time. Its, its, disefficient.

How can PowerPoint cause loss of confidence? If the material is there, surely the student should understand it, right? It's coming in the ears and eyes at the same time, right? Saturation bombing the brain, right? That works. Right? Name a war where saturation bombing worked and I'll show you a war in which there was no fundamental misunderstanding to begin with.

Can the destruction of schema be useful? Perhaps in advertizing, in which the marketer wants to remove any barriers to the consumer's decision to buy. The marketer can make room for their own framework, their reasons for buying the product, by selectively destroying, or at least temporarily weakening, the consumer's schema, which is likely the product of a lifetime of hard knocks.

Avoid PowerPoint. If you lecturers use it, ask your teachers to not use it. If that doesn't work, avoid class. If you lecture, don't use it. If you are at a business meeting, decide before the first slide is shown whether you really want to allow this person to tear down your knowledge of the business you're in. This dichotomy of PowerPoint and good schema is realized implicitly by anyone who appreciates the irony of drug company education programs for doctors. We need to tell teach others about this. Schema, unfortunately, is Latin, which is very useful academically, because it's easily adopted by a mind interested in studying it and brings with it little to nothing in the way of background, but it's not a metaphor, which makes it ill-suited to widespread acceptance. We need a better word. Not just a word, a metaphor. Perhaps PowerPoint itself is the best metaphor available, but to appreciate it, we still need to introduce the concept that schema is the framework.

Posted by Niels Olson at September 21, 2006 2:32 PM

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