Nullhüpoteesin

Nullhüpotees, often denoted as H0, is a fundamental concept in statistical hypothesis testing. It represents a statement of no effect or no difference between populations or variables. The primary goal of hypothesis testing is to determine whether there is enough statistical evidence to reject this null hypothesis in favor of an alternative hypothesis (H1), which suggests that there is an effect or difference.

For example, if a researcher is testing a new drug, the null hypothesis might state that the drug has no effect on patient recovery time, while the alternative hypothesis would state that the drug does shorten recovery time. Researchers collect data and use statistical tests to evaluate the probability of observing such data if the null hypothesis were true. This probability is known as the p-value.

A low p-value (typically below a predetermined significance level, alpha) suggests that the observed data are unlikely under the null hypothesis, leading to its rejection. Conversely, a high p-value indicates that the data are consistent with the null hypothesis, and it cannot be rejected. It is important to note that failing to reject the null hypothesis does not prove it is true, but rather that the evidence is insufficient to conclude otherwise. The null hypothesis serves as a baseline assumption against which observed evidence is compared.