Testing of hypothesis, also known as hypothesis testing, is a statistical method used to determine whether there is enough evidence to reject or not reject a null hypothesis based on sample data. The test of significance is a key component of hypothesis testing and involves assessing the probability of obtaining a sample statistic as extreme as, or more extreme than, the one observed, assuming that the null hypothesis is true.
Here’s a step-by-step overview of the test of significance:
1. Formulate the Hypotheses:
- Null Hypothesis (H0): This is the hypothesis to be tested. It typically represents the status quo or no effect. It is denoted as H0.
- Alternative Hypothesis (H1 or Ha): This is the hypothesis that contradicts the null hypothesis. It represents the effect or phenomenon of interest. It can be one-tailed (e.g., greater than, less than) or two-tailed (e.g., not equal to).
2. Choose a Significance Level (α):
- The significance level, denoted as α, is the probability of rejecting the null hypothesis when it is true. Commonly used values for α include 0.05 (5%) and 0.01 (1%).
3. Select a Statistical Test:
- The choice of statistical test depends on the nature of the data and the research question. Common tests include t-tests, chi-square tests, ANOVA, correlation tests, and regression analysis.
4. Collect Sample Data:
- Collect a representative sample from the population of interest. The sample size should be determined based on factors such as desired power and precision.
5. Calculate the Test Statistic:
- Compute the test statistic based on the sample data and the chosen statistical test. The test statistic measures the difference between the observed data and what would be expected under the null hypothesis.
6. Determine the Critical Region:
- Based on the significance level (α) and the chosen test, determine the critical region or rejection region of the test statistic. This is the range of values that, if the test statistic falls within it, leads to rejection of the null hypothesis.
7. Compare the Test Statistic to the Critical Region:
- Compare the calculated test statistic to the critical region. If the test statistic falls within the critical region, reject the null hypothesis. If it falls outside the critical region, fail to reject the null hypothesis.
8. Draw Conclusion:
- Based on the comparison, draw a conclusion regarding the null hypothesis. If the null hypothesis is rejected, it suggests evidence in favor of the alternative hypothesis. If the null hypothesis is not rejected, there is insufficient evidence to support the alternative hypothesis.
9. Interpretation:
- Interpret the results in the context of the research question and discuss the implications of the findings.
It’s essential to note that hypothesis testing does not prove or disprove hypotheses definitively but rather assesses the strength of evidence against the null hypothesis based on sample data. Additionally, statistical significance does not necessarily imply practical significance, so it’s crucial to consider the effect size and context when interpreting results.