Alternative hypothesis

Definition

An alternative hypothesis is a statement that suggests a potential outcome that contradicts the null hypothesis. It indicates the presence of an effect or difference.

5 Must Know Facts For Your Next Test

1. The alternative hypothesis is typically denoted as $H_1$ or $H_a$.
2. It proposes that there is a statistically significant effect or difference.
3. The alternative hypothesis can be one-sided (directional) or two-sided (non-directional).
4. Rejecting the null hypothesis in favor of the alternative hypothesis implies that the sample data provides sufficient evidence to support $H_1$.
5. The type of test (e.g., t-test, z-test) and significance level ($\alpha$) affect whether the null hypothesis can be rejected.

Review Questions

• What does rejecting the null hypothesis imply about the alternative hypothesis?
• How is the alternative hypothesis represented symbolically?
• What are the two types of alternative hypotheses in terms of directionality?

Related terms

Null Hypothesis: A statement suggesting no effect or no difference, typically denoted as $H_0$. It serves as the default assumption to be tested against.

Significance Level: $\alpha$, which is the threshold for determining whether a result is statistically significant. Commonly used values are 0.05, 0.01, and 0.10.

p-value: The probability of obtaining test results at least as extreme as those observed during testing, assuming that the null hypothesis is true.