From Description to Inference
Descriptive statistics tell you what happened. Inferential statistics tell you whether what happened is meaningful. Hypothesis testing is the bridge between observation and conclusion.
The Hypothesis Testing Framework
- H₀ (null hypothesis) — no effect or no difference
- H₁ (alternative hypothesis) — there is an effect or difference
- p-value — probability of observing the data if H₀ is true
- α (significance level) — threshold for rejecting H₀, typically 0.05
Key Takeaway
A p-value below α means you reject the null hypothesis — but always consider effect size and practical significance alongside statistical significance.