The Chapter 5 Worksheet was mostly about finding results while controlling for other variables. Controlling for other variables is important because it prevents spurious results. Two variables might seem correlated at first, but controlling for another related variable can show whether or not the results are important. A common example is the positive correlation between buying ice cream and crime. When controlling for weather, we can hypothesize that people are less likely to be at home in good weather and more likely to be out buying ice cream, increasing the occurrence of break-ins.