Case file
Insensitivity to Sample Size
- Filed under
- Not Enough Meaning
- Also recorded as
- sample size neglect
The charge
Insensitivity to sample size is treating small samples as if they are just as reliable as large ones.
How it operates
People lean on representativeness and the law of small numbers, so a few vivid observations feel more diagnostic than they are.
Logged incidents
- Incident 01
A growth team chooses a new ad creative after 20 clicks because the early conversion rate looks amazing.
- Incident 02
A support manager scraps a script after three angry tickets even though the overall volume is tiny.
- Incident 03
A hiring committee decides a candidate is exceptional because four interviewers agreed, ignoring how noisy interviews are.
What to watch for
Ask: How big is the sample, and how wide would the confidence interval be?
Recommended action
Use confidence intervals, power thinking, or Bayesian updating instead of reading too much into tiny samples.
Known associates
- ConfabulationConfabulation is unintentionally filling gaps in memory or explanation with details that feel true but were…
- Clustering IllusionClustering illusion is seeing meaningful streaks or clumps in data that are actually compatible with…
- Neglect of ProbabilityNeglect of probability is reacting to how vivid or scary an outcome is while giving too little weight to how…
- Anecdotal FallacyAnecdotal fallacy is letting one or two vivid stories outweigh broader and better-quality evidence.
- Illusion of ValidityIllusion of validity is feeling highly confident in a judgment because the evidence forms a neat story, even…
- Masked-Man FallacyMasked-man fallacy is treating differences in what is known about something under one description versus…
Source of record