Read an Academic Passage

[1]Working memory is the mental system that holds information for a few seconds while we use it, for example when we remember a phone number long enough to type it. Its capacity is small. In the 1950s, researchers suggested that people could hold about seven items at once, but later studies put the figure closer to four. Because reading, problem solving and decision making all depend on this system, its limits affect almost every kind of learning.

[2]Cognitive load theory applies these findings to teaching. It holds that some mental effort comes from the difficulty of the material itself, while some is extraneous, created by poorly designed instruction. When the total load is greater than working memory can handle, learners become confused and remember less. Good teaching materials therefore try to remove avoidable demands so that learners can spend their limited capacity on understanding the content.

[3]One example is the redundancy effect. When a narrator reads aloud exactly the same words that appear on the screen, learners must process both versions and check that they match. Instead of helping, this repetition often reduces learning. For this reason, designers now tend to pair spoken explanations with diagrams rather than with identical on-screen text.