Dr. Grace recruits 60 women to participate in a laboratory experiment. None has ever played golf or tried a video game of the sport. Using a Wii system, each woman plays only one game, either alone or in front of a four-person or an eight-person audience. The first 3 participants are randomly assigned, one to each of the three conditions. Then the next 3 participants are randomly assigned, such that each condition now has a total of 2 participants. This continues until there are 20 participants in each condition. Dr. Grace records how well participants perform. Which specific type of between-subjects design is used in this experiment