Questions: Question 3 4 pts The authors of the paper "Action-Video-Game Alters the Spatial Resolution of Vision," (Psychological Science[2007]:88-94) concluded that spatial resolution, an important aspect of vision, is improved by playing action video games. They based this conclusion on an experiment in which 32 volunteers who had not played action video games were "equally and randomly divided between the experimental and control groups." Subjects in each group played a video game for 30 hours over a period of 6 weeks. Those in the experimental group played Unreal Tournament 2004, an action video game. Those in the control group played Tetris, a game that does not require the user to process multiple objects at once. Based on this description of the experiment, which control is part of the experiment design? Check all that apply. a control group random assignment direct control blinding

The answer is:

• a control group
• random assignment

Explanation for each option:

1. a control group: Correct. The experiment included a control group that played Tetris, which does not require the user to process multiple objects at once. This group serves as a baseline to compare the effects of playing an action video game.

2. random assignment: Correct. The volunteers were "equally and randomly divided between the experimental and control groups," ensuring that each participant had an equal chance of being assigned to either group. This helps to eliminate selection bias and ensures that differences between groups are due to the treatment rather than pre-existing differences.

3. direct control: Incorrect. Direct control typically refers to the experimenter's ability to control extraneous variables directly. While the experiment does control for the type of game played, it does not mention controlling other variables directly, such as the environment in which the games were played or the participants' prior experience with video games in general.

4. blinding: Incorrect. Blinding refers to keeping the participants, experimenters, or both unaware of which group the participants are in to prevent bias. The description does not mention any blinding procedures, so we cannot assume that blinding was part of the experiment design.