Adult-Gerontology Clinical Nurse Specialist (CNS) Practice Exam

What is the expected difference in values between subjects from the same sample called?

1. Sampling error

2. Refusal rate

3. Sample attrition

4. Random variation

The correct answer is: Random variation

The expected difference in values between subjects from the same sample is referred to as random variation. This concept recognizes that within any statistical sample, there are natural fluctuations and discrepancies due to a variety of factors, including individual differences in the subjects themselves. Random variation is an important aspect of statistical analysis because it affects the precision and reliability of estimates. For example, when measuring a specific attribute, such as blood pressure or cholesterol levels, each subject will likely exhibit some level of variability due to biological differences, measurement error, and environmental influences. Understanding random variation helps in designing studies and interpreting results, as researchers can factor this variability into their analyses. The other options, while relevant in different contexts, do not specifically refer to the inherent differences observed among subjects within a sample. Sampling error refers to the difference between a sample statistic and the corresponding population parameter, refusal rate deals with the proportion of participants who decline to participate in a study, and sample attrition addresses the loss of participants during a study. Thus, random variation is the correct term for describing the differences expected among individual subjects within the same sample.