Stanford Open Policing. The Stanford Open Policing project gathers, analyzes, and releases records from traffic stops by law enforcement agencies across the United States. Their goal is to help researchers, journalists, and policymakers investigate and improve interactions between police and the public. The following is an excerpt from a summary table created based off of the data collected as part of this project.
| Driver’s | No. of stops | % of stopped | |||
| County | State | race | per year | cars searched | drivers arrested |
| Apaice County | Arizona | Black | 266 | 0.08 | 0.02 |
| Apaice County | Arizona | Hispanic | 1008 | 0.05 | 0.02 |
| Apaice County | Arizona | White | 6322 | 0.02 | 0.01 |
| Cochise County | Arizona | Black | 1169 | 0.05 | 0.01 |
| Cochise County | Arizona | Hispanic | 9453 | 0.04 | 0.01 |
| Cochise County | Arizona | White | 10826 | 0.02 | 0.01 |
| Wood County | Wisconsin | Black | 16 | 0.24 | 0.10 |
| Wood County | Wisconsin | Hispanic | 27 | 0.04 | 0.03 |
| Wood County | Wisconsin | White | 1157 | 0.03 | 0.03 |
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What variables were collected on each individual traffic stop in order to create to the summary table above?
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State whether each variable is numerical or categorical. If numerical, state whether it is continuous or discrete. If categorical, state whether it is ordinal or not.
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Suppose we wanted to evaluate whether vehicle search rates are different for drivers of different races. In this analysis, which variable would be the response variable and which variable would be the explanatory variable?