The Assertion-Evidence Approach to Scientific Presentations

Scientific Presentationsby Chris Grabau, Instructional Developer, Reinert Center

In his 2003 book, The Craft of Scientific Presentations: Critical Steps to Succeed and Critical Errors to Avoid, Associate Professor of engineering communication at Pennsylvania State University,  Michael Alley describes how an “assertion-evidence” approach to scientific presentations can create powerful and memorable learning experiences.  Instead of presenting information using bulleted lists and topical phrases, Alley demonstrates how to build presentations using succinct messages that are supported by relevant visual evidence (such as photos, drawings, diagrams, films, or equations).  For example, an assertion-evidence presentation on land erosion may use pictures of the causes and effects for land erosion instead of a series of text-heavy bulleted lists.  Handouts on each slide will include references and other supporting information in the “notes” section of the slide.  The picture-based presentation helps create a capacity for a more complex understanding of the material while also providing an opportunity for the presenter to break free from the restriction of text-based slides.

Now in its 2nd edition, the book offers many great examples of more engaging and less engaging presentations as well as some of the common mistakes made when presenting information.  The book also demonstrates how the assertion-evidence approach helps create presentations that are better comprehended, remembered, and believed (Garner & Alley, 2013).

Recommended for anyone looking to improve the way they present material by using visual aides (such as PowerPoint), the book is full of examples based on the assertion-evidence presentation model.  In addition to the book, there are a wealth of resources provided on the author’s website including a number of free online templates to help you get started using the assertion-evidence framework.

If you’re looking for a way to make your lectures more interactive, Alley’s approach to designing slides may be of interest.


Alley, M. (2003). The craft of scientific presentations. New York: Springer.

Garner, J., & Alley, M. (2013). How the Design of Presentation Slides Affects Audience Comprehension: A Case for the Assertion–Evidence Approach. International Journal of Engineering Education, 29(6), 1564-1579.

 Image courtesy of