What a 95% CI Means

Your click-through rate is 10% (95% CI: 8% - 12%)

Wrong interpretation: "There's a 95% chance the true value is between 8-12%"

Right interpretation: "If I repeated this measurement 100 times, 95 of those intervals would contain the true value"

Practical Use

Wide intervals = high uncertainty = need more data

Narrow intervals = high precision = confident estimate

Overlapping CIs

If two confidence intervals overlap, the difference might not be statistically significant. But you need a proper test to be sure.

Why They're Better Than P-Values

• ✅ Show effect size (not just significance)
• ✅ Display uncertainty visually
• ✅ Help with practical decisions
• ✅ Don't rely on arbitrary thresholds