This example gets students thinking about how we operationalize variables. Psychologists operationalize a lot of abstract stuff. Intelligence. Grit. But what about something that seems more firmly grounded and countable, like whether or not a crime meets the criteria for a a mass shooting? How do we define mass shooting? As shared in this article by Chris Wilson for Time Magazine , the official definition is 1) three or more people 2) killed in a public setting. That is per the current federal definition of a mass shooting . But that isn't universally excepted by media outlets. The article shares different metrics used for identifying a mass shooting, depending on what source is being used. Whether or not to include a dead shooter towards the total number killed. Whether or not the victims were randomly selected. I think the most glaring example from the article has to do with the difference that this definition makes on mass shooting counts: You could also discuss wi...