AP Biology: Chi-Square Test and Hypothesis Testing

Flashcards focusing on key vocabulary and definitions related to the chi-square test and hypothesis testing in AP Biology.

Chi-Square Test

A statistical test used to compare observed data with expected data to determine if there is a significant difference between them.

P-value

The probability of obtaining a result equal to or more extreme than what was actually observed in the dataset.

Degrees of Freedom

The number of distinct possible outcomes minus one, often used in statistical tests.

Null Hypothesis (H0)

A statement that assumes no effect or no difference; it is the hypothesis that researchers aim to test against.

Alternative Hypothesis (H1)

A hypothesis that proposes a significant difference exists between variables, counter to the null hypothesis.

Significant Result

A test result that shows a statistically significant difference, typically determined by the p-value being below a certain threshold (e.g., 0.05).

Expected Frequencies (E)

The theoretical frequencies of outcomes that would be expected if the null hypothesis were true.

Observed Frequencies (O)

The actual counts observed in the experiment.

Chi-Square Formula

χ² = Σ((O - E)² / E), a formula used to calculate the chi-square statistic.

Critical Value

The threshold value that the calculated chi-square statistic must exceed in order to reject the null hypothesis.