The curriculum specialist for a large school district wanted to evaluate the use of a new math curriculum for elementary school students. Elementary schools were assigned to one of two conditions: One group of schools used the existing math curriculum; another group of schools used the new curriculum. Scores on the state level math exam were compared. What research design methodology should be used? Group of answer choices Single case research design is most appropriate. Either group research design or single case research design could be appropriate. Group research design would be appropriate. None of these are correct