Recently, John Sweller, the developer of Cognitive Load Theory in 1988, has put forth new empirical evidence suggesting that data comprehension is significantly decreased if the same data is delivered in verbal and written form simultaneously. His quote now blazing its way around the net: “The use of the PowerPoint presentation has been a disaster. It should be ditched.” Sweller, Edward Tufte, and others critical of the presentation app have been called for the slideware’s demise for some time; however, presentation software is like a pistol. After all, guns don’t kill people…

It is worth examining the countless “decks” that originate within the walls of Idea City in light of Sweller’s findings. In our case, the medium is truly the message and whether we are using slideware as a tool to persuade, to inform or to educate, knowledge of the learning process as it pertains to new information is key. But what does it mean to understand? As defined by Sweller, understanding is the ability to process all data elements that necessarily interact simultaneously in working memory. In other words, information is composed of discreet bits of data and those elements interact to form larger, more intricate ideas. How well we as an audience can process the information determines the degree of comprehension.

Sweller discusses a number instructional effects, though the greatest relevancy to GSD&M is found within the ideas of modality and redundancy. Modality takes into consideration that people learn via the visual and/or the auditory processors of working memory, ideally utilizing both systems simultaneously. One interesting finding: the most effective learning occurs when an audience is presented with information paired both visually and verbally that is otherwise unintelligible when solely presented in either mode. Dated wisdom suggests that one should “reinforce” the verbal with the visual, hence the text-heavy, bullet-riddled slides that have become unfortunately commonplace. That approach is not only aesthetically lacking but also impedes the cognitive process, leading to the second notable effect: redundancy. The redundancy effect occurs when an audience is presented with all needed information simultaneously in both visual and auditory modes, merely repeating information found in either channel. This creates an unnecessary cognitive load, taxing the finite capacity of working memory as the audience works to relate what they’re reading with what’s being said, only to discover the data is essentially one in the same and any point the presenter was attempting to verbalize has been missed.

Executive summary:
Slides strictly designed to compliment, not reinforce the spoken word = good
Slides burdened with lines of text, paraphrased presenter’s notes, or designed to be read (by either audience or presenter) = bad

So death to PowerPoint? Not just yet. It, along with the other apps living in the hard drives on our desks are but tools, each with a unique set of strengths and weaknesses. Slideware need not be the default app for any presentation. Regardless, consider teaching your next presentation rather than telling it with instructional design principles guiding your creative choices, not the default slideware toolset.

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“If your presentation visuals taken in the aggregate (e.g., your “PowerPoint deck”) can be perfectly and completely understood without your narration, then it begs the question: why are you there?”
-Garr Reynolds, former Manager of Worldwide User Group Relations at Apple