Bad News for Slideware Users
Researchers at Purdue University have some bad news for the 40 million people worldwide who deliver “standard” slide-driven presentations each and every day.
When slides are used, the researchers concluded, the audience retains nearly 30 per cent less than if presenters eliminate PowerPoint and simply talk to their audience.
In other words, by simply turning off your projector and using your slides as notes, you can significantly enhance your communication effectiveness.
Two Styles of Lectures
The researchers conducted their study as part of a course entitled “Human Factors in Engineering” that was delivered to students from four majors—engineering, humanities, management and technology. The course was attended by both undergraduate and graduate students and was taught three times a week for 16 weeks.
There were two separate streams of classes for the course, which was based on the textbook Human Factors in Simple and Complex Systems.
For two lectures, two distinctly different delivery styles were used—one that showed slides during the lecture and one that did not.
Researchers then used a 20-question quiz to test students’ ability to recall information in four categories: oral information presented during lectures, graphic information presented during lectures, alphanumeric information from the lectures, and information presented orally with visual support.
The Negative Affect of Slides
The researchers’ first hypothesis was that PowerPoint would have a negative effect on what was said during the lecture—that it would be more difficult for the audience to listen to the presenter while slides are shown.
And there is no question this is true. Students who didn't see slides during the lecture scored 29 per cent higher on the quiz in recalling oral information, and achieved higher overall scores with the recall of all information. “The presence of PowerPoint negatively affected the recall of auditory information,” the researchers concluded, adding that “graphic scores reveal there was no notable gain when using PowerPoint to display graphic information.
“The same could be said for alphanumeric information. There was no notable gain for using PowerPoint vs. the chalkboard.”
Ever spent hours putting a slide together? According to this research, that effort was virtually a complete waste of time.
But the news gets even worse for habitual users of all slideware programs. In addition to testing lectures with and without slides, the researchers also tested those people who didn’t attend class at all during the two lectures in which the comparison was made. Unbelievably, those who didn’t attend either lecture “heard” more than those who attended the slide-driven lecture.
“The negative affect that PowerPoint has on the retention of auditory information is similar to not attending class and hearing the information at all,” the researchers wrote in their conclusions.
In other words, if you use slides, your audience is better off reading your slides and skipping the meeting, webinar, training session or conference at which those slides were presented. They’ll understand and retain more.
Fortunately, if understanding and retention are important to your business success, you can enhance both with one simple action:
Turn off the projector, or close the deck, and simply talk to your audience.