Take the tap test before you present
Literally tap out a melody and notice how obvious it is to you — but invisible to listeners.
Why it works
The tap test (from Elizabeth Newton’s 1990 dissertation, popularized by the Heaths) makes the curse of knowledge visceral: tappers who know the song predict 50 % of listeners will recognize it; actual recognition is roughly 2.5 %. The experience forces an expert to feel the gap between their internal signal and what others receive. That felt gap is the calibration data experts normally lack.
How to do it
- Tap out a well-known song on a table and ask a colleague to name it.
- Before you reveal the song, guess what fraction of people will get it right.
- Compare your guess to the actual result — the ratio is your personal curse-of-knowledge index.
- Apply the same calibration question before any explanation: "What fraction of my audience has never heard this?"
Evidence
Newton (1990) showed tappers predicted ~50% recognition; actual rate was ~2.5%, a large and consistent gap. The Heaths used it as the anchor example for the curse of knowledge in Made to Stick. Camerer, Loewenstein & Weber (1989) demonstrated the same knowledge-imputation bias in controlled economic experiments, and Birch & Bloom (2007) traced it to a difficulty suppressing one’s own knowledge when reasoning about what others believe — evidence the tap test illustrates a general effect, not a one-off curiosity. (observational)
This is a single lab paradigm, not a systematic review; it illustrates rather than quantifies the effect in real-world teaching settings.
Sources
- Newton, E. (1990), The Rocky Road from Actions to Intentions (Stanford dissertation)
- Camerer, C., Loewenstein, G., & Weber, M. (1989). The Curse of Knowledge in Economic Settings: An Experimental Analysis. Journal of Political Economy, 97(5), 1232–1254.
- Birch, S. A. J., & Bloom, P. (2007). The Curse of Knowledge in Reasoning About False Beliefs. Psychological Science, 18(5), 382–386.
Common mistake
Using the tap test once as a party trick rather than as a recurring calibration practice before any high-stakes explanation.
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More practices for The Curse of Knowledge: Why Experts Struggle to Teach
- Find a genuine novice to test your explanation on
Before the real audience, explain to someone who actually doesn’t know.
- Open with a concrete story, not with your framework
Lead with a specific, sensory narrative before introducing any abstraction.
- Run a jargon audit on every key explanation
Go word by word through your explanation and mark every term a newcomer would not know.
- Ask what the audience already knows before explaining
Probe prior knowledge explicitly rather than assuming it.
- Build a bridging analogy from what they know to what they don’t
Map the new concept onto a structure the audience already understands.
- Work backwards from what the learner needs to do
Start with the decision or action the learner must take, then trace back only to the knowledge that serves it.
- Deliberately slow down at conceptual transitions
Pause, name the transition, and check understanding before moving to the next idea.
Related concepts
- Concrete Examples: How to Make Abstract Ideas Stick
The cognitive mechanism behind examples and how to deploy them without fooling yourself
- The Feynman Technique, Step by Step
Explain it simply, find the gaps, and close them
- Make It Stick: The Science of Learning
Retrieval, spacing, interleaving, and elaboration — the evidence-backed core
- Deliberate Practice, Not Just Practice
Focused, feedback-driven practice at the edge of your ability