Working memory is a well-known limitation for learners. A rule of thumb, based on numerous research studies is that somewhere between five and eight elements can be held simultaneously in working memory to be manipulated and processed together. Working memory is closely related to the concept of “cognitive load” – basically how much learning the brain can handle at a given point. Sweller, Cognitive load theory, learning difficulty, and instructional design in Learning and Instruction, Volume 4, Issue 4, 1994, Pages 295–312.
“The basic idea of cognitive load theory is that cognitive capacity in working memory is limited, so that if a learning task requires too much capacity, learning will be hampered. The recommended remedy is to design instructional systems that optimize the use of working memory capacity and avoid cognitive overload.”
There are numerous strategies for reducing cognitive load. One of these is the use of redundancy.
Information acquisition theory posits three delivery routes for information: pictures, spoken word, or written word. The theory predicts that students will learn more deeply from multimedia presentations when redundant on-screen text is included rather than excluded.
The theory has been supported by studies such as Mayer, R. E., & Johnson, C. I. (2008). Revising the redundancy principle in multimedia learning. Journal of Educational Psychology, 100(2), 380 and Mayer, R. E., & Moreno, R. (2003). Nine ways to reduce cognitive load in multimedia learning. Educational Psychologist, 38,43-52.
Both studies compared the learning outcomes of students who had exposure to the redundancy of pictures, narrative audio, and on-screen text throughout slides of a lecture and those who had only images and narrative audio on slides. Moreno & Mayer’s work found that those who were exposed to all three types of information received an average of 79 percent more correct answers on a problem-solving test than those who only received the spoken audio and images. The Mayer & Johnson study confirmed the result of students retaining more information when they are exposed to more types of information simultaneously.
These studies showed that redundant information is advantageous to learning, as long as it is kept brief, and placed close to the information to which it relates. Other methods for reducing cognitive load described in Mayer and Moreno’s article include segmenting (chunking information into smaller pieces), “signaling,” (“providing cues to the learner about how to select and organize the material”) and “weeding” (eliminating extraneous material). Contact ATIG if you’d like to meet with an Instructional Strategies Specialist for more ideas on reducing cognitive load and improving learning.