Research
Introduction to Hypothesis Testing
Hypothesis testing is a fundamental aspect of statistical analysis, which allows
researchers to make inferences about populations based on sample data. It involves
formulating assumptions and using statistical tools to test these assumptions. Two key
hypotheses are crucial in this process: the null hypothesis (H0) and the alternative
hypothesis (H1).
Null and Alternative Hypotheses
Definition and Role
• Null Hypothesis (H0): This hypothesis posits that there is no effect or no
difference. It is a statement of no difference or no relationship and serves as the
default assumption that the research seeks to test. For instance, in studying the
IQ of Unisa students compared to the general population, the null hypothesis
would suggest that there is no difference between the two groups.
• Alternative Hypothesis (H1): Contrary to the null hypothesis, the alternative
hypothesis suggests that there is a significant effect or a difference. It indicates
the presence of an effect that the research aims to validate. In the same
example, the alternative hypothesis would propose that the IQ of Unisa students
differs from that of the general population.
Mutual Exclusivity
• These hypotheses are mutually exclusive, meaning only one can be true. The
null hypothesis is always a precise statement, while the alternative hypothesis
can be less specific, indicating a range of possible values .