Regan wants to study how reading on a computer affects comprehension among elementary school students. Regan thinks that girls and boys might differ and he also suspects that grade level will affect the results. He decides to create a male and a female group for each grade. Within each group, he randomly assigns half of the students to read an article on paper and half of the students to read the article on a computer. Which type of experimental design does this situation illustrate? a. Completely Randomized
b. Randomized Block
c. Double-Blind
d. Matched-Pair