BUSINESS SPEAK · MOE
MOE: Margin of error
How far a survey result could be from the true figure.
What it means
For a share p from n people, the 95% margin of error is about 1.96 × √(p × (1 − p) ÷ n). A result of 52% ± 3% means the real figure is likely between 49% and 55%.
Where you’ll meet it
- If two results are closer than their margins allow, the race is too close to call.
- Asking 4 times as many people only halves the margin of error.
Worked example
Scenario: A poll asks 1,000 people and 50% say yes.
- 0.5 × 0.5 ÷ 1,000 = 0.00025
- √0.00025 ≈ 0.0158
- 1.96 × 0.0158 ≈ 3.1%
Answer: The result is 50% ± about 3.1 points.