A goodness-of-fit test determines if a sample data matches a population with a specific distribution. It assesses the discrepancy between observed and expected frequencies.
Chi-Square Distribution: A probability distribution used in tests of independence and goodness-of-fit for categorical data.
Null Hypothesis: A statement that there is no effect or no difference, often denoted as $H_0$.
Expected Frequency: The frequency of occurrences predicted by a theoretical model, assuming the null hypothesis is true.