Without a doubt the most often quoted presentation related research is the 1981 3M/Wharton study. The second most frequently quoted research is the 1986 University of Minnesota/3M study. The purpose of this Presentation Facts article, and the one that will follow it, will be to provide brief overviews of these two studies.
What does this oft quoted but little understood research really say… and how does it relate to us today?

Both Wharton and UM/3M are foundational presentation studies, and much of the subsequent work I have read reference one or the other or both. A quick internet search returns dozens of Web pages that reference the Wharton study in some way. Often partial or erroneous information is attributed to this research. While still a significant problem among many who write about presentation matters today, overstating the Wharton study is not new. In 1986 Douglas R. Vogel wrote the following in the introduction to the UM/3M Study:

“Although there have been many claims made regarding how presentations are improved by visual support, there is little empirical evidence to back up the claims. The study conducted in 1981 at the Wharton School of the University of Pennsylvania is the one empirical study that is often cited, but frequently the claims exceed the study’s explanatory capabilities.”

The results from Wharton were used to aggressively sell presentation products and services, which may account for the often exaggerated claims. Another problem seems to be that once information gets distorted, subsequent published papers and documents cite the erroneous source. It is like the game you played as a kid where a whisper gets passed along through a dozen or so players and the final content has no resemblance to the original statement.

Background:
As of this writing, I have not been able to get my hands on a copy of the actual Wharton document which is entitled “A Study of the Effects of the Use of Overhead Transparencies on Business Meetings”, Wharton Applied Research Center, Wharton School, University of Pennsylvania, 1981. Lynn Oppenheim is the author of the study report. The Wharton Applied Research Center became a private organization in 1987 and today is called The Center for Applied Research (CFAR). Ms. Oppenheim is its president.
The information presented in this article comes from direct quotations found in a 1981 3M brochure or credible references to the report in other research of that period. I hope to update this entry if needed when (and if) I can get a copy of the report itself.

The Wharton study was not designed to measure retention or to compare the effectiveness of any specific characteristics of presentation visuals (like text, images, graphs or charts). This study compared facilitated meetings with presentation support to facilitated meetings without presentation support. The presentation support used was overhead transparencies. I have not been able to find examples of the overhead content used.

While I don’t have detailed methodology, I do know that the eight week study involved 123 MBA students who participated in 36 group meetings to decide whether or not to introduce a fictional new product. According to 3M literature from 1981, “These meetings were carefully designed to simulate the evaluations and decision-making processes of the real business world.” Without seeing the exact study design, it is impossible to evaluate this statement or know what “carefully designed” means.

The information in the meetings was presented by two speakers — one who used overheads and one who did not. An obvious question I cannot answer today is how they controlled for the variability of presenter styles, skills and overall speaker effectiveness in a facilitated meeting environment.

According to the 3M literature I have, the study was designed to examine 1) Does the use of overhead transparencies (OH) affect either individual or group decisions? 2) Does OH use affect perceptions of the presenter? and 3) Does OH use affect characteristics of the meeting, perceived effectiveness or the interaction patterns of participants?

Results:
The primary result of this study was that the presenter who used OHs was “perceived as significantly better prepared, more professional, more persuasive, more highly credible and more interesting” than the one who did not. In 1986, Doug Vogel would confirm this result in the UM/3M study using both overheads and 35mm slides (B&W and color).
Additional results include:
1) Group decisions were reached faster with OHs
2) Meetings were an average of 28% shorter with OHs
3) The presenter using OHs won more favorable responses to the business propositions regarding the introduction of the new product
4) Lengthy verbal monologues were decreased and verbal exchanges among participants were increased when OHs were used.

Discussion:
The speaker/facilitator in any meeting situation represents a huge variable. Until I know how they controlled this variable it is hard for me to have confidence in the results of this study. Vogel (1986) would later use a recorded presentation that took the presenter out of the equation as a variable. This seems to me to be a much better way to study the effect of visuals.

Can the results of this study using overheads (an informal and interactive presentation support media) be generalized to a business environment where PowerPoint presentations (more formal and less interactive) are the norm? I really am not sure, but I don’t think it should be automatically accepted as a fact that they can be.
As Presentation Professionals, are we comfortable relying so heavily on a 20 year old study using visual support that few in the business world use today? There are more recent investigations like the Presentations study (2000), but that research did not look at perceptions of the presenter in any way that is comparable to Wharton. We will take a look at the Presentations study in detail in a subsequent article.

It is fair to say that the Wharton study is an important foundational work and provides a number of valuable presentation insights. It should be quoted accurately, however, and not be used to support presentation theories it was never designed to investigate.