Based on observing more than 400 drivers in the Atlanta area, two investigators at Georgia State University concluded that people exiting parking spaces did so more slowly when a driver in another car was waiting for the space than when no one was waiting (“Territorial Defense in Parking Lots: Retaliation Against Waiting Drivers,” Journal of Applied Social Psychology [1997]: 821-834). Describe how you might design an experiment to determine whether this phenomenon is true for your city. What is the response variable? What are some extraneous variables and how does your design control for them?