Question

Sampling bias exists when: A. the sample is representative of the population. B. the sample is not representative of the population. C. two variables are confounded. D. the effect of the independent variable can't be isolated.

Short answer

A. Sampling bias exists when the sample is representative of the population. B. Sampling bias exists when the sample is not representative of the population. C. Sampling bias exists when two variables are confounded. D. Sampling bias exists when the effect of the independent variable can't be isolated. Answer: B. Sampling bias exists when the sample is not representative of the population.

Step-by-step solution

Understanding Sampling Bias

Sampling bias occurs when a sample is not representative of the entire population from which it was drawn. This can lead to incorrect or misleading conclusions about the population. To identify the right option, you must look at each statement and decide whether or not it describes a situation where sampling bias would exist.

Evaluating statement A

Statement A says that sampling bias exists when the sample is representative of the population. This statement is incorrect because sampling bias happens when the sample is unrepresentative or biased in some way.

Evaluating statement B

Statement B suggests that sampling bias exists when the sample is not representative of the population. This statement correctly defines sampling bias as an issue that arises when the sample does not accurately represent the entire population.

Evaluating statement C

Statement C claims that sampling bias exists when two variables are confounded. Confounding refers to a situation where the relationship between two variables is intertwined or mixed up with the influence of a third variable. Although confounding may occur alongside sampling bias, the two concepts are not the same, and thus statement C is incorrect.

Evaluating statement D

Statement D states that sampling bias exists when the effect of the independent variable can't be isolated. This situation would affect the internal validity of a study rather than being an issue with sampling bias. Therefore, statement D is not correct.

Identify the correct statement

After evaluating each statement, we have determined that statement B accurately defines sampling bias. Sampling bias exists when the sample is not representative of the population, which may lead to incorrect or misleading conclusions about the population.