The big idea
🥄
Stirring beats spoon size
A random 1,000 can represent millions. A biased million represents nobody in particular.
Statistics for Everyday Life · Lesson 1
Sampling and Surveys
beginner⏱ 18 min · 7 cards
Try it
Who Was Missed?
“A website poll about parking, answered by readers who clicked the article.”
What is distorting this survey?
Identify what is distorting each survey.
Compare
Two scoops
Random
Resembles the jar
Tap.
tap for example ↻
Biased
A magnet for red
Tap.
tap for example ↻
Margin of error describes the wobble in the first picture. It says nothing about the second.
Key term
What it does not cover
A poll says ±3. Is that the total uncertainty?
tap to reveal ↻
No — sampling only
It quantifies the luck of who was drawn, assuming selection, response, and wording were all handled perfectly.
Nuance
Nine out of ten
Maester Note
Out of how many? Which ten? Asked how? Run how many times? Unanswerable questions are the point of the phrasing.
Quick check
Why can a random sample of 1,000 represent millions?
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