In part 1 of this post, I briefly described the background and study design of the UM/3M research conducted by Doug Vogel in 1986. In this post, I will highlight the primary results along with some interesting information I had never heard before about a small side study Vogel did with some “extra” subjects in this study.

If you haven’t reviewed part 1 of this post, please do so because it is the excellence of the design and conduct of this study that lends credibility to the findings. Vogel intended this work to be a baseline for continuing research and in the design of this study has given us a great model of what quality research in the use of presentation visuals looks like.
Results
1) The primary outcome of this study was that “presentations using visual aids were found to be 43% more persuasive than unaided presentations”. This finding was supportive of the primary finding in the Wharton Study conducted five years previously. These results are more impressive than the 1981 results because of the excellent design of this study compared to the questionable design of the Wharton research.

Remember that Vogel’s research subjects were asked to invest time and money into time management seminars. These seminars were briefly described to them before a pre-test was given. Several weeks later a presentation was given to them. The chart to the left depicts the change in responses from the pre-test to the post-test after the presentations. The investment of time was considered the most accurate measure since students might have varying amounts of disposable income to spend, but at least in theory, they all had the same amount of time to invest. Subjects who saw the presentation accompanied by visual support were positively influenced to spend significantly more time and money on the time management seminars. These results were highly statistically significant with p values less than .003. This means that there were less than 3 chances in 1000 than the results were due to a random occurrence.

2) The persuasive impact of a presentation depends on characteristics of the support used. Presentation support in color is more persuasive than that in black and white. Use of overhead transparencies resulted in the presenter being perceived as more interesting, but less professional that the presenter using 35mm slides. This information may be of limited use today since presenters almost always present in color and use neither overheads nor slides.

3) Image enhanced graphics were not more persuasive than text-based visuals. Many today might find this surprising. The image enhancement used was very rudimentary by Presentation Professional standards today, however, it might be safe to say that simple clip art might not add any value to a presentation visual over the use of the text alone (ie a bullet list). Clearly more research needs to be done on this.

The Role of the Presenter
For me, some of the most interesting findings from this research came out of a side study Vogel did with some extra groups of subjects he held in reserve in case he had problems with one of the study groups and needed a backup. Since there were no problems, he used these extra groups to evaluate the difference between an “average” presenter and a “significantly better presenter”. When he auditioned presenters, he picked what he and his colleagues felt was an excellent presenter and had this person videotaped giving the same presentation as before. They then tested this presenter against the “average” presenter using no visuals, hand drawing on overhead transparencies and the computer generated text support.

1) The better presenter was more persuasive than the average presenter when neither of them used visuals. This of course is what we would expect.

2) An average presenter using visuals was as effective as a “better” presenter using no visuals. This is an important finding and a key indicator of the value Presentation Professionals can bring to their clients who are not expert presenters.

3) Interestingly, the better presenter did much worse than the average presenter when both used hand drawn overheads. In fact, the better presenter was 18% less persuasive than the average presenter when both used low quality visuals. This might indicate that the better a presenter is, the more important it is for him/her to have high quality presentation materials developed.

4) As expected, when both used high quality visuals, the better presenter was more persuasive than the average presenter.

Summary
Although conducted almost 20 years ago, this is a comprehensive and well designed study resulting in information valuable to us today. It is a great baseline for others to build on. The persuasive model Vogel developed is a model Presentation Professionals should become acquainted with. Our ongoing research and discussion should focus on how to use visuals to leverage each component of the Persuasion Process: Attention, Comprehension, Yielding/Agreement and Retention ultimately leading to Action.

Vogel clearly demonstrated that visuals enhance persuasion. (In the studies we have reviewed thus far however, it has not been proved that simple graphic enhancements are more effective than text only visuals.)

Finally, Vogel leaves us with some very interesting questions about how visuals effect excellent presenters. As Presentation Professionals, have we considered that the visuals we develop for our excellent presenting clients could actually make them less effective?

Read Part 1