Remove explanations the learner has already internalized

Stop explaining what an expert already knows — redundant information adds cognitive load, not value.

Why it works

When an expert encounters an explanation of material already schematized, two processes run in parallel: processing the incoming explanation and comparing it to the existing schema. This comparison is effortful and consumes working memory without contributing new information. Removing the redundant element frees that working memory for higher-level processing.

How to do it

1. Periodically ask the learner to explain a concept back: if their account is accurate, stop re-explaining it.
2. In written materials, use progressive disclosure — provide full explanation on first pass, then abbreviate in subsequent encounters.
3. Let learners signal when coverage of a topic is no longer adding value.

Evidence

The redundancy effect in cognitive load theory is well documented: adding information the learner already knows to a learning presentation reliably reduces learning outcomes compared to omitting it. Kalyuga, Chandler & Sweller (1998) ties the effect directly to expertise, showing that explanatory material which aids novices becomes redundant and load-inducing for higher-expertise learners. (rct)

Redundancy effects are most pronounced in high-complexity domains; for simple material, redundancy may be neutral rather than harmful.

Sources

• Sweller & Chandler (1994), "Why some material is difficult to learn", Cognition and Instruction
• Sweller, J., & Chandler, P. (1994). Why some material is difficult to learn. Cognition and Instruction, 12(3), 185–233.
• Kalyuga, S., Chandler, P., & Sweller, J. (1998). Levels of expertise and instructional design. Human Factors, 40(1), 1–17.

Common mistake

Repeating foundational information before every advanced lesson "to make sure everyone is on the same page" — in practice, this reliably reduces performance in the advanced learners and rarely brings the novices along.