Researchers found that when PowerPoint was used, the audience had nearly 30 per cent less retention than if the presenter had eliminated the PowerPoint entirely and just talked with his or her audience. Just by eliminating PowerPoint alone, they became significantly better and more effective presenters.
Purdue researchers delivered a course entitled “Human Factors in Engineering”. It was open to both graduate and undergraduate students from the following majors: engineering, management, humanities and technology. Three times a week for 16 weeks, researchers divided the classes into two lecture formats. One format delivered with PowerPoint the other without. Researchers then tested the students in four categories: oral, graphic and alphanumeric information presented during the lectures and information presented orally with visual support.