Four students were doing internships at the Social Science Research Institute of their university. The research institute had a contract to do a series of studies on traffic safety for the downtown development agency of a small city near the university. The internship students were assigned to carry out a study to determine how likely it was that cars actually came to a stop at intersections with stop signs at pedestrian crosswalks in the downtown area.

You are to respond to the following questions that the students are considering in planning their study.

A. The students want to distinguish the extent to which the cars stop beyond a “yes” or “no”

classification. How could the students develop an operational definition for the cars stopping that would include cars that came to a full stop, came to a rolling stop, and did not stop at all?

B. What steps could the students take before beginning to collect data for the actual study to increase the interobserver reliability of their observations?

C. The students are interested in determining the likelihood that cars will stop when pedestrian traffic downtown is light and when it is heavy.

What time-sampling plan could the students use to make this determination?

D. The students are especially interested in determining the likelihood of cars stopping at the stop sign independent of whether other cars have stopped. How would the students need to sample the cars they observed in order to study the independent stopping of cars?

What information could the students record that would allow them to include all cars in their sample and still determine the likelihood of cars stopping independently?