One of the challenges when learning statistics is becoming comfortable analyzing situations using mathematical models. Students have seen some algebraic modeling; for instance, in algebra they may determine a linear pricing structure or model the trajectory of a ball using a quadratic equation. It is a difficult departure for students to design their own models for data. They are given freedom to explore potential alternatives, and are released from the stricture of a perfect fit to a textbook correct answer, but this can be terrifying. It is like going from painting-–by-–number to mixing your own palette and creating an original work.
In order for students to fully examine the implications of a situation, they must be willing to make assumptions that are possibly incorrect. They need to argue both sides of a case, asserting one hypothesis, while collecting evidence against it. This is not unlike the process of examining the evidence of a crime. That process is familiar to most of us, having been widely fictionalized in books, movies and television. It is not only a great analogy to prepare students for inference, but holds a great deal of interest for most students.
The purpose of this unit is to identify the specific types of data that are collected in crime scene investigations, present the relevant background or biology involved, and use this knowledge and statistical tools to create theories and hypothesis about the solutions to crimes. This setting frees students to inhabit the place of mystery and to feel comfortable in not knowing an exact answer. We will be poised together on the edge of discovering the answer to a riddle about a crime. My goal is that students learn to see mathematics as the tool to predict answers about which no one owns the truth.