The study that shows effects of using visuals in presentation neglects to lead the readers to the famous conclusion.
Note: This is part 4 of a series of posts reviewing some of the origins of scientific claims that compare text vs visuals. Access part 1 here. Access part 2 here. Access part 3 here.
If you would like to follow along, you can find the original article that I’m reviewing from University of Minnesota website.
The paper we are looking at is titled, “Persuasion and the Role of Visual Presentation Support: The UM/3M Study” prepared by Douglas R. Vogel, Gary W. Dickson, and John A. Lehman.
We have been talking about various quantitative claims that many use to validate power of visual communication. While I don’t disagree about the power and potential of using visuals to convey a message, some of the cited references had some hazy origins. Since my work depends on scientific and medical accuracy, I constantly read journal articles and attend scientific talks. I am very familiar with the general setup of a research paper.
Last time we took a look at the second part of the results of a paper that claims that using visuals will make a presentation 43% more persuasive. The study continues to be highly questionable while showing graphs and charts with no numbers. The authors spend time talking about statistical significance of the results, but the p values are expressed in arrows. My mass-spectrometrist boyfriend asked about error bars. What error bars?
To add to the confusion, the study mixes control and variables, makes connections to data points that are unrelated, show the same graph with different results without explanation, and comes to a conclusion that color overhead transparencies are the best.
To keep on track, this study was supposed to compare how students reacted to presentations with or without visuals.
Here’s my approximate interpretation of how this study is set up. I will use a very familiar example: comparing chocolate and vanilla ice cream:
After the results are shown (kind of) and left many questions unanswered (while answering topics that were not questioned), the paper then goes onto give advice about how to give a good persuasive presentation. Let’s take a look.
The Model of the Persuasion Process (Discussion?)
I skipped figure 1 in the M/M because it made no sense to me. Now they want to compare it to the next figure, figure 10. So, let’s put them side by side.
OK, I must admit, I still don’t get it. I think the figure is combining directional flow (arrows) with increase in strength/quality (arrows). They also say that the width of the arrows meant different things. Wow.
The study states,
“The knowledge presented in Figure 10 should allow a presenter to selectively employ visual support depending on the outcome that is desired,
e.g., if the goal is to enhance comprehension and retention, This slideshow could not be started. Try refreshing the page or viewing it in another browser.