19.07.2017 by Marisa Krystian

Presentations play a big role in our modern lives. We experience them in school, in the workplace, and even in personal settings. While presentations are important, basic questions remain about how to present effectively. How do ‘medium’ and ‘message’ impact communication? What software tools and visual aids are most effective?

Harvard University wanted to find answers to these questions, which is why they conducted a study comparing the effectiveness of three commonly-used formats for communication: verbal only, PowerPoint, and Prezi.

Harvard’s Department of Psychology recently published the study in the journal PLOS ONE titled, Does a Presentation’s Medium Affect Its Message? Let’s go over the experiments they conducted, the shocking results, and the main takeaways you’ll want to remember for your next presentation.

Key Players

Oral Presentations – Oral presentations have been a part of the human experience since the dawn of time. Oral (or non-visual) communication is a great way to tell stories, impart tradition, and preserve history.

PowerPoint – Microsoft’s presentation platform has populated the scene for decades; for better or for worse. PowerPoint is known for its sequential, linear transitions, and the formation of a slide deck. Slides may contain text, graphics, sound, movies, and other objects, which may be arranged freely.

Prezi – Released in 2009, Prezi has quickly emerged as the go-to business and educational presentation tool. Prezi is known for its zoomable user interface (ZUI). It allows users to arrange images, graphics, text, audio, video, and animations on one large visual canvas, as opposed to a deck of stacked slides.

The Experiments

Harvard researchers conducted a double-blind study on the effectiveness of presentation techniques, broken up into two experiments.

Experiment 1: In the first phase, participants with sufficient experience in oral, PowerPoint, and Prezi presentation formats were randomly assigned to create a presentation in one of those formats.

Harvard researchers provided the necessary context, instruction, and time to create a short but realistic presentation. Participants then presented live over Skype to select members of the study, who judged each presentation’s efficacy.

  • Harvard recruited 146 individuals who participated as presenters in the study.
  • Harvard recruited 153 audience participants from the Harvard Decision Science Lab.

Experiment 2: Video recorded versions of these presentations (from Phase One) were presented to a larger online audience, affording Harvard greater statistical power and allowing them to measure the impact of presentation format on decision-making and learning.

  • 1069 respondents in the final dataset. Participants completed the experiment entirely online.

The Results

Participants evaluated Prezi presentations as more organized, engaging, persuasive, and effective than both PowerPoint and oral presentations. In fact, PowerPoint presentations were rated as no better than verbal presentations with no visual aids at all. Users rated the three formats on a scale from 1 to 5 in a few major categories.

This finding was true for both live and prerecorded presentations, when participants rated or ranked presentations, and when participants judged multiple presentations of different formats or only one presentation in isolation.

Presenters giving Prezi presentations were also noted as being “more knowledgeable and professional” by their audience.

Main Takeaways

The Medium Says Something About You

Not only does the medium affect how your audience absorbs your message, it also gives them ideas about you – the presenter. The medium you use to present can alter people’s perception of you and your brand, which is why it’s important to pick a tool that has been proven to make you look professional, organized, and knowledgeable.

In the case of Prezi, good design and exciting animations lead to a better presentation experience for the audience. The best way to persuade and convince the viewer is to give them a truly compelling presentation.

Zooming Reigns Supreme

The study concluded that Prezi’s interactive format and zooming user interface make presentations more effective, engaging and persuasive. The study found the results “reflect a true and specific benefit of Prezi over PowerPoint or, more generally, ZUIs over slideware.”

The audience reported that zooming in and out of a virtual canvas was a more favorable experience overall when compared to slide decks and oral presentations.

People Want Visuals

Participants were asked to rate whether the presentation had ‘not enough,’ ‘too much’ or an ‘about right’ amount of text, graphs, images, and animations. People rated the visuals from Prezi presentations as more “dynamic, visually compelling, and distinctive” than PowerPoint.

When it came to graphs and animations, viewers indicated that there were not enough graphs or animations in PowerPoint presentations when compared to Prezi.


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