- Unless typefaces are large enough, letters can’t easily be distinguished from each other. 
- If the color of text or graphics isn’t clearly distinct from the color of the background on which they appear, they can’t be readily distinguished from each other.
- Typefaces in which letters are similar (like because they’re all uppercase, all bold, etc.) can’t be easily read. 
- Viewers can easily distinguish texture patterns in which elements (like stripes) vary by at least 2:1. 
- Viewers can easily distinguish orientations of the lines in different regions when they vary by at least 30 degrees. 
- Finally, humans have difficultly focusing on red and blue at the same time, so text and other fine lines are hard to distinguish if they’re rendered in deep blue or red.


The Principle of Discriminability’s Corollaries 

The P.D. means that two properties (such as two colors, degrees of gray, or sizes) can’t convey different information unless they differ by a large enough proportion to be easily distinguished. 

Ohio State University, Columbus

When viewing a sequence of slide, the audience primarily will encode what they see, and if they fail to encode material, it may as well not even exist. The follow three principles cover encoding processes in this context: Discriminability, Perceptual Organization, and Salience.

Encoding Processes

Kosslyn, S. M., Kievit, R. A., Russell, A. G., & Shephard, J. M. (2012, July 17). PowerPoint® Presentation Flaws and failures: A psychological analysis. Frontiers. Retrieved September 22, 2022, from https://www.frontiersin.org/articles/10.3389/fpsyg.2012.00230/full 

PowerPoint® Presentation Flaws and Failures: A Psychological Analysis

Classical grouping “Laws” specify the perceptual conditions that guide viewers to see elements in a single group. For example, people tend to group together elements that are nearby (The Law of Proximity). Similarly, we group together elements that appear similar (The Law of Similarity). 

Other Information Processing Laws

The Principle of Discriminability 

The P.P.O. entails that people automatically organize elements into groups, which they then attend to, and remember more accurately. 

Principle of Perceptual Organization

The P.L.C. states that people have a limited capacity to retain and process information, and won’t understand a message if too much information needs to be memorized and processed. 

Learn Before

Related

Learn After