The Craft of Scientific Presentations

The Craft of Scientific Presentations
Reported by
Jaclyn Jansen

Posted March 21, 2012

Presented By

Presented by the Science Alliance


Scientists use presentations as a primary means to communicate their work to a broader audience. From research updates at informal lab meetings to the presentation of high impact findings at international conferences, each talk is an opportunity to excite the audience with a researcher's unique and novel work. The goal is simple: scientists seek to present their data with clarity and enthusiasm so that the audience will understand and remember their work. Yet too many of these presentations are confusing and disorganized, leaving the audience lost. Therefore, on September 7, 2011, Melissa Marshall presented a seminar at the Academy titled The Craft of Scientific Presentations to help scientists communicate their work more effectively. Marshall, who teaches presentation skills to scientists at Pennsylvania State University, used a combination of lecture, discussion, and examples to offer insight into the key elements of a successful presentation and to demonstrate concrete strategies for designing effective slides.

Marshall described the three key elements of a successful presentation. First, the content of the presentation must be strong and must convey important ideas. Stunning science produces a memorable presentation. Marshall suggested Stephen Hawking, the theoretical physicist, as an example of a presenter who is famous for the amazing content of his talks. Second, the presenter should be passionate and enthusiastic about his or her data. According to Marshall, Professor of Public Health Science Hans Rosling best embodies these qualities. As a dynamic and energetic speaker, he presents his data so that they are at once vivid and focused. His talks excite and engage the audience, yielding a highly effective presentation. Finally, for a successful presentation, the scientist should tailor the content so that it is appropriate for the audience. For example, neuroscientist Jill Bolte Taylor masterfully eliminates extraneous detail and jargon to allow the audience to focus on the salient points of her presentation. Her talks are accessible to the audience. Together, these three elements—content, enthusiasm, and accessibility—produce a presentation that the audience will understand and remember.

Melissa Marshall emphasized the three most important elements of an effective scientific presentation: content, enthusiasm, and accessibility for the audience. She offered examples of presenters who successfully employ these strategies and concrete methods to improve any presentation. (Image courtesy of Melissa Marshall)

Beyond the broad elements of a successful presentation, appropriate slide design is critical for an effective talk. Yet Marshall pointed out that the slide design offered in a traditional PowerPoint template acts as barrier to a clear and organized presentation. The hierarchical, bulleted list presents too much textual information. The printed words on the slide compete with the words spoken by the presenter. The audience cannot simultaneously process both the written and the spoken word and must ignore some of the information. Rather, Marshall noted, an image is much more effective at communicating an idea. The bulleted list that is found in a PowerPoint slide also encourages the presenter to offer too many details. The focus of the slide is often lost in extraneous information, and the presenter risks confusing the audience.

In contrast to the bulleted list in a PowerPoint template slide, an effective slide design uses an "assertion–evidence" model. In this model each slide contains a full sentence assertion as the headline, describing an insight, feature, or result. This text is a concise, focused summary of the main message of the slide. The assertion headline is then supported by visual evidence. This image conveys more than words alone. For example, pictures can offer the audience an instant impression of the context or setting behind an idea that might require hundreds of words to describe. Graphs display a multitude of data points, demonstrating trends that the audience can grasp without verbal explanation. The assertion and image not only help the audience grasp key concepts, but also assist the speaker in preparing a more organized talk. Since each slide must have a focus that is summarized through a single sentence and image, this type of slide design acts as a filter for eliminating superfluous detail.

Marshall offered examples of how the assertion–evidence model of slide design can be applied throughout a presentation, from the title slide to the conclusion slide. The title slide should move beyond simply presenting the authors and sponsors of the work. Instead, it should orient the audience to the main idea of the presentation. The headline should convey the goal of the talk. When combined with an image, this slide can engage the audience and entice them to listen carefully to the rest of the presentation. Most talks follow the title slide with a bulleted outline of the sections that will be presented. This map is important for the audience to know what to expect from the talk, but the bulleted list is too easily forgotten as soon as the slide has passed. Rather, Marshall suggested using selected images from each section of the talk along with a headline to provide an overview of the presentation.

Slides showing scientific results constitute the majority of the remainder of the presentation. These slides should follow the design principles mentioned above, with the key finding as the headline and with primary emphasis placed on the image. High quality images and bold, high contrast colors allow the audience to easily interpret data. Minimal text can highlight important aspects of the results. This text can be animated to appear or disappear creating emphasis without clutter. For the conclusion of a presentation, Marshall suggested altering the traditional final slide away from a bulleted list. She advocated stating the most important finding of the talk as the assertion headline and using a visual from the presentation as an illustration. This slide should be on the screen throughout the question and answer period to reinforce the key message of the talk.

The seminar concluded with a brief sample presentation from Genevieve Brown, one of Marshall's former students and a current graduate student in bone bioengineering at Columbia University. Her research update style talk illustrated how the assertion–evidence slide design can be used to effectively describe research to an audience of colleagues. Further examples of other slides that use this design scheme can be found under the Resources tab.

Use the tab above to find multimedia from this event.

Media available:
Workshop led by Melissa Marshall (Pennsylvania State University)



Becoming an Effective Presenter of Engineering and Science
The goal of this Penn State University website is to help scientists and engineers with their technical presentations. It includes examples and instruction on how to design a successful scientific presentation.

Rethinking the Design of Presentation Slides: The Assertion-Evidence Structure
Examples of the assertion-evidence slide design by Michael Alley, who originated this slide design layout, can be found on this Penn State University website.

View the TED talk of Hans Rosling, an example of a highly enthusiastic presenter.

View Jill Bolte Taylor's TED talk, an example of a speaker effectively connecting with her audience.


Alley, M. The Craft of Scientific Presentations. New York: Springer; 2003.

Mayer, R. E. Multimedia learning (2nd ed). New York: Cambridge University Press; 2009.

Reynolds, G. Presentation Zen: Simple Ideas on Presentation Design and Delivery. California: New Riders; 2008.

Duarte, N. slide:ology: The Art and Science of Creating Great Presentations. California: O'Reilly Media Inc; 2008.


Melissa Marshall

Pennsylvania State University
e-mail | website

Melissa Marshall is a lecturer of Communication Arts and Sciences at Pennsylvania State University, where she has been teaching since 2004. Marshall works with the College of Engineering to design and implement effective teaching methods of communication skills for engineering and science students. Marshall codeveloped and is the lead instructor for the Effective Scientific Presentations course that is offered to engineering students at Penn State.

In addition to teaching at Penn State, Marshall gives invited lectures and workshops at other institutions. She teaches a workshop entitled "The Craft of Scientific Presentations," a short course for graduate students, faculty, and professionals that seek to make their research presentations more memorable, understandable, and persuasive. Among the institutions where Marshall has been invited to lecture are Cornell University's Weill Cornell Medical College, Harvard Medical School, University of Illinois, University of Michigan, Laval University (Québec), and the National Institution of Occupational Safety and Health (a division of the CDC). Additionally, Marshall provides annual scientific communication workshops to the Simula Research Laboratory in Oslo, Norway. In March 2009 she was invited to co-teach a national course on scientific communication to Norwegian PhD students in the science fields. This course took place in Oslo as a national effort by Norwegian universities and companies to improve the technical communication skills of their PhD students. Marshall holds a BA in Advertising/Public Relations, a BA in Communication Arts and Sciences, and a MA in Communication Arts and Sciences, all from Pennsylvania State University.

Jaclyn Jansen, PhD

Jaclyn Jansen earned her PhD in biochemistry, molecular biology, and cell biology from Northwestern University. As a graduate student she studied a conserved network of proteins that control mother-daughter differentiation in budding yeast. Currently, Jansen is a postdoctoral fellow in Bruce Stillman's lab at Cold Spring Harbor Laboratory. She is studying chromatin remodeling during DNA replication. In addition to her activities at the bench, Jansen is particularly interested in science outreach programs that bring research science to the broader public audience.