Which of the following is an example of a matched pairs design? A. A teacher calculates the average scores of students on a pair of tests and wishes to see if this average is larger than 80%. B. A teacher compares the pre-test and post-test scores of students. C. A teacher compares the scores of students using a computer based method of instruction with scores of other students using a traditional method of instruction. D. A teacher compares the scores of students in her class on a standardized test with the national average score.

B. A teacher compares the pre-test and post-test scores of students

Step-by-step explanation:

the answer is true, because it is a good example to compare the tests between students, we know that a matching pair design is a random model and is used when the experiment allows grouping subjects in pairs based on a variable and each pair will receive randomly a different handling, the answer A is not true because in the example all students are uniformly averaged and the variable is not correlated with subgroups, option c is incorrect because the variable was not randomized and generates classification bias and the option d is incorrect because the teacher compares a small sample as her class with a score of a total sample, but does not intervene on her students when selecting the corresponding group