In the last post in my series covering the book Crime Analysis For Problem Solvers we looked at the necessity to collect our own data. Now that we have the data we need to start our analysis by Step 22 - Examine Your Data Distributions.
I have a confession to make, I never did well in math in school. In fact, if you were to ask my high school math teachers what kind of job I would have as an adult, they definitely would not have guessed one that involves any sort of mathematical competency. Yet, as a crime analyst I spend a lot of time crunching numbers. I like to tell people, I have a calculator with a lot of buttons and I have to use them all.
The authors state:
“After collecting your data you need to know what it is telling you.”Analysis is the art of learning what the data is telling you. A good way to analyze the data is with statistics. I can hear you all groaning right now. You probably didn’t like statistics when you took it in high school or college. One thing I found is that while I didn’t like math in school because didn’t see the point, now that it can do some very useful stuff and make my life easier, I think it’s pretty neat. What’s even better is that you don’t have to worry about the whole theoretical framework behind how and why statistics work and just concentrate on learning what is useful.
The authors discuss a few basic statistical tools for analyzing data distributions. These tools analyze the average case or the spread of cases. To analyze the average case you can use:
- Inner Quartile Range
- Standard Deviation
- Nominal scales
- Ordinal scales
- Ratio scales
Next time we’ll cover Step -23 Diagnose Your Hot Spot.