Is it real, or just noise?
Results bounce around by chance. Statistics helps you tell a real difference from a lucky streak.
The Coin-Flip Intuition
Flip a fair coin 10 times and get 7 heads? Not surprising. Flip it 1,000 times and get 700? Something's going on. More data makes chance easier to rule out.
Sample size
Small samples swing wildly. Plan the size before you start.
Significance
How unlikely the result would be if nothing had really changed.
Effect size
How big the difference is. Small effects need big samples.
Duration
Run whole weeks, so weekday and weekend behaviour both count.
Source: Omni Calculator ↗
Small samples tell tall tales.