Hypothesis testing is a statistical method used to make decisions based on data. It involves formulating a null hypothesis, which represents a default position, and an alternative hypothesis, which represents a new claim. Researchers collect data and use statistical tests to determine whether there is enough evidence to reject the null hypothesis in favor of the alternative. The process typically involves calculating a p-value, which indicates the probability of observing the data if the null hypothesis is true. If the p-value is lower than a predetermined significance level, usually set at 0.05, the null hypothesis is rejected, suggesting that the alternative hypothesis may be true.