This document discusses hypothesis testing. It defines a hypothesis as a predictive statement that relates independent and dependent variables and can be scientifically tested. The purpose of a hypothesis is to define relationships between variables. Characteristics of a good hypothesis are outlined. Null and alternative hypotheses are defined, with the null being what is currently assumed to be true. Type I and Type II errors in hypothesis testing are explained. Common statistical tests used to test hypotheses are described briefly, including t-tests, z-tests, F-tests, and chi-square tests. Key concepts like significance levels, confidence intervals, and contingency tables are also summarized.