Question

An appropriate statistical tool used to compare the differences among three or more than three groups is:

• A. t-test
• B. Correlations
• C. ANOVA
• D. Regression

Hint:

Remember:
2 groups $\to$ t-test.
$\ge 3$ groups $\to$ ANOVA (Analysis of Variance).
This is a standard rule of thumb in biostatistics.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
When comparing sample means across different experimental groups, the choice of statistical test depends on the number of groups being compared.

Step 2: Detailed Explanation:
1. A Student's t-test is used to compare the means of exactly two groups.
Using multiple t-tests to compare three or more groups increases the probability of making a Type I error (false positive).
2. Analysis of Variance (ANOVA) is a statistical technique developed to compare the means of three or more independent groups simultaneously.
It partitions the total variance in the dataset into variance between groups and variance within groups to test if at least one group mean is significantly different from the others.
3. Correlation measures the strength and direction of a linear relationship between two variables, while Regression models the relationship between dependent and independent variables.
Neither is used to compare group means.

Step 3: Final Answer:
ANOVA is the appropriate statistical tool to compare differences among three or more groups.