An Instructor Randomly Assigns Two Sections of His Course to an Experimental

question 7

Multiple Choice

An instructor randomly assigns two sections of his course to an experimental condition (new teaching method) or control condition (regular teaching method) .Students in the 9:30 section receive the experimental treatment and students in the 1:30 section participate in the control condition.At the end of the semester the instructor's tests reveal that students in the 9:30 section had higher test scores than students in the 1:30 section,based on a test of statistical significance.Based on this summary,we can state that

• A)the results are uninterpretable because of intact groups.
• B)the findings have external validity across two times of day.
• C)the experiment has internal validity.
• D)all of these