Question

School A would like to get more high school students to ride the school bus rather than driving to school each day to reduce traffic congestion around the school. To try to encourage more students to ride the bus, the school decides to raise the daily rate for parking in the school parking lot.

1. Design and describe a study that uses an interrupted time series design to provide evidence as to whether the parking rate increase led to an increase in daily school bus ridership. What evidence would support the idea that the parking rate increase in the School A caused an increase in school bus ridership?

2. Suppose you conclude that school bus ridership increased when the parking rate increased. Identify and describe an example of a threat to internal validity that exists that would limit your ability to attribute the increased ridership to the increase in the parking rate?

3. Describe how you could change the study to utilize a control series design to answer the same question about the relationship between the parking rate increase and school bus ridership. If a study were conducted using a control series design, what results would support the idea that the parking rate increase in the School A (rather than some other factor) caused an increase in school bus ridership?

Answer 1