Each bill has all kinds of useful information on it: how much it costs, when payment is due, and information about consumption.
Below is a graph from our water bill comparing usage from year to year. I find this data to be useful, as it indicates a potential issue that needs our attention.
As you can see below, there was a huge drop in usage from July to September, 2013-2014. Did we all of a sudden become concerned about how much we were watering our lawn, washing our car, power-washing our siding? Possibly, but not true. Living in a high-plains desert, we're always concerned about water conservation. Turns out, we had a major leak that we finally tracked down and fixed. Interestingly, you'll note water consumption in June didn't drop as much after we fixed that first leak. That's because, you guessed it, there was another leak in a different place. Water is insidious!
I don't know if I wasn't paying attention before (entirely possible), but our utility company started sending their own versions of data featuring usage feedback in a monthly newsletter, mailed separately from the bill. Here's one of the graphs.
At first glance, we're right up there with all our neighbors who have homes nearby and approximately the same size as ours. We're rated good! We even got a smiley face. We've changed out many light bulbs (not all), purchased energy-efficient appliances, and are conscientious about turning appliances off when we're not using them. I'm feeling pretty good about this. "Good" is good, right?
Upon a more careful perusal of the first graph, in the fine print and typed really lightly, I saw we were evaluated at the low end of good (those smiley faces can be so deceiving!) and we've almost tipped the scales to just a stone's throw away from "more than average." Well, we can't let that happen!
That's when I started thinking about the missing variables in the data.
- There are MANY homes around here that have solar on them. We're not one of them...yet. ( I had it on my last home and really liked it.) They're getting a boost from that big star in our solar system. I'm OK with that.
- The weather will determine how much energy we use, regarding heating and cooling. Extremes in either direction will ensure more usage.
- Are those other "occupied" homes really occupied during the day or do they turn their air up? I work at home and, since I can't play tennis right now and HATE being hot, we use our air conditioner- responsibly!
- And, since I'm working from home, I'm on my computer most every day for at least 6 hours (unless someone calls and says, "Let's do lunch!" In that case, I'm outta here!)
- How many people occupy each of these homes? There are 3 people that live here and we all use electricity. This is an older neighborhood and hasn't completely made the transition of seniors moving out and younger families moving in. It makes a difference.
- Do the other homes let the electric company control their usage with the Saver Switch. Keeping our AC at a responsible level and not liking to be hot (I get really cranky), I can control our AC very well without their help.
- This relates to #2, only, in the winter. If you're not home during the day, it makes sense to turn the heat down, and we do...when I'm not home. But sitting at the computer with teeth chattering and wearing fingerless gloves is not my idea of a good time. I call this the Dr. Zhivago syndrome.
I could go on with my first-world list of issues, but you get the idea. The point is, data can be helpful when the variables remain constant. That said, this last graph at least compares apples to apples. We'll see what the weather has in store for us and how it affects our energy consumption.
I hope you enjoyed my Math IS Real Life mini-diatribe against questionably-presented data. It felt good to get it off my chest. :)
Be sure to stop by the other Math IS Real Life blogs in this month's hop.
4mulaFun, The Teacher Studio, Teaching to Inspire in 5th, AND MissMathDork
"Data, I think, is one of the most powerful mechanisms for telling stories. I take a huge pile of data and I try to get it to tell stories." Steven Levitt