How the Design of Headlines in Presentation Slides Affects Audience Retention

INTRODUCTION The defaults for typography and layout in Microsoft PowerPoint, which has 95 percent of the market share for presentation slide software (Parker 2001), compel presenters to create headlines that are single words or short phrases. Not surprisingly, in a typical PowerPoint presentation, the main assertion of each slide is relegated to appear in the slide’s body. For those creating slides for presentations, the question then arises: Is such a headline design the most effective at having the audience retain the slide’s main assertion? According to Robert Perry of Hughes Aircraft and Larry Gottlieb (2002) of Lawrence Livermore National Laboratory, the answer is “no.” Since the 1960s, Perry has argued for a succinct sentence headline on presentation slides. Following Perry’s lead, Gottlieb came to the same conclusion during the 1970s at Lawrence Livermore Laboratory. For the next three decades, although a number of technical communicators strongly advocated using sentenceheadline designs, the overwhelming majority of headline designs projected at engineering and scientific conferences were single words or short phrases. Recently, in the midst of complaints from popular media (Parker 2001; Schwartz 2003) about the use of PowerPoint in presentations, several publications, including Alley (2003a), Doumont (2005), and Atkinson (2005), repeated the old arguments and presented new ones for using headlines that are sentences. Sentence headlines have several main advantages over phrase headlines (Alley and Neeley 2005). First, a sentence headline such as Placer deposits arise from the erosion of lode deposits orients the audience much more effectively to the slide’s purpose than does a phrase headline such as Placer Deposits. Second, using sentence headlines allows the presenter to emphasize the most important detail of the slide. Third, if well chosen, sentence headlines present the audience with the key assertions and assumptions of the presentation. Explicitly stating these assertions and assumptions in a technical presentation is advantageous because audiences are more inclined to believe the presentation’s argument if they comprehend the assertions and assumptions of that argument (Toulmin 2003). Finally, once the headline assertion has been determined, the presenter is in a much better position to select persuasive evidence to support that assertion. This article presents an experimental study on the effect of sentence headlines in four sections of a large geoscience course that typically had 200 students per section. In the study, the four different sections of students were taught the same information by the same instructor, with the only difference being the design of the teaching slides. Of the four sections of students, two sections viewed the information on slides that used mostly phrase headlines (note that some of these original headlines were formatted as questions, and a few slides did not have any headlines). The remaining two sections viewed the same information on slides that used succinct sentence headlines. In the slide transformations, other changes occurred, such as typographical changes and conversions of bullet lists to more visual evidence. However, for the 15 slide transformations considered in this study, the principal change was the conversion of a traditional headline to a succinct sentence headline. After each class period, all four sections of students