Which of the following is not a principle of making inferences from dependent samples?

• A. Use the differences between paired observations for analysis
• B. Account for the pairing or matching of observations
• C. Assume the samples are independent of each other
• D. Check that the differences are approximately normally distributed

Answer: (C)

Verified step by step guidance

1. Understand that when making inferences from dependent samples (also called paired samples), the key idea is that observations are linked or matched in some way, such as measurements before and after a treatment on the same subjects.
2. Recognize that one fundamental principle is to analyze the differences between paired observations rather than treating the samples as independent groups. This means calculating the difference for each pair and then performing statistical tests on these differences.
3. Remember that because the samples are dependent, you must account for the pairing or matching in your analysis. Ignoring this pairing would violate the assumptions of dependent sample methods.
4. Check the distribution of the differences to ensure that they are approximately normally distributed, especially if you plan to use parametric tests like the paired t-test, which assumes normality of the differences.
5. Identify that assuming the samples are independent of each other is incorrect in the context of dependent samples, as this assumption contradicts the very nature of paired or matched data.