After watching nursery-school children, Ken Garoo wants to test the hypothesis that some toys are more fun to play with than others.

After watching nursery-school children, Ken Garoo wants to test the hypothesis that some toys are more fun to play with than others. He decides to compare "fun" toys (blocks) with "unfun" toys (stuffed animals). He also wishes to see if there is a sex difference, as well, so sex is added as an independent variable. What kind of design is needed?