For a number of months I have been going through the excellent book, Crime Analysis For Problem Solvers. I highly recommend this book for crime analysts, police officers, detectives and anyone else who regularly has to deal with solving complex crime problems. While I have been commenting on each chapter in the book, I encourage you to read the entire book as well. The authors are way smarter and more erudite than I am.
In this post I'm going to cover Step 32 - Conduct Case Control Studies. Have you ever wondered why some locations or businesses have crime problems and some do not? For example, in my sleepy burg, we have some bars that are a significant problem and some that have not had a police call for service there in years. Why are these two places different? The way to identify factors that contribute to the difference is by conducting a case - control study.
The authors define the process steps as:
- Define your cases precisely.
- Select a representative sample of these cases.
- Define a group of controls that could have been troublesome but did not become troublesome even though they were exposed to similar conditions (e.g., in the same neighborhood or city, serve the same types of clients, etc.).
- Select a representative sample of these controls.
- Compare the characteristics of the cases to the characteristics of the controls.
Case-control studies are different from most other studies and require special techniques to analyze data. Step 33 describes one technique that is particularly useful.In the next post, we'll look at this technique when we cover Step 33 - Measure Association.