The Signal and the Noise

The signal is the truth. The noise is what distracts us from the truth.
--Nate Silver, The Signal and the Noise

The Signal and the Noise is my favorite book about statistical analysis. (Yes, I have a favorite book about statistical analysis. Don't judge.) The book's author Nate Silver runs a website called FiveThirtyEight.com, a name derived from the number of electoral votes in United States presidential elections. Silver is most famous for correctly predicting the electoral results of 49 out of 50 states in the 2008 presidential election, and then topping that feat by correctly predicting all 50 in 2012.

In the book, Silver discusses how we humans naturally observe and seek out patterns, and how we often fail to successfully make accurate predictions based on those observations. This is in part because there is so much information out there, and much of the information is noise. It distracts us from what we really need to know to accurately analyze the information available to us.

Thanks to unit pre and post tests in math and ELA (as well as those that are now being developed in other subject areas), we have a wealth of data about our students and their proficiency on a wide range of Iowa Core standards. As Southeast Polk's assessment coordinator, I have been looking for ways to share more and more data with teachers, coaches, and administrators to help facilitate our common goal of raising student achievement. Using Data Director, Infinite Campus, and Excel, I've been able to develop reports not only on overall test data, but also on subgroups based on IEP, ELL, TAG, and gender. I've gone back and found historical data in these areas as well. And I think this is probably just the tip of the iceberg in terms of what sort of data could be available to everyone.

The problem becomes how to deal with all of that data. How do we decide what is important right now, what needs to be observed for future patterns, and what can be dismissed? How do we separate the signal from the noise?

The answer lies in the data team process. A strong data team has the ability to hone in on the signal, on the important truths that our unit assessment data can tell us about what our students are doing well, and in what areas they need more help. I've been privileged enough to attend a few data team meetings since the start of the school year, and I'm looking forward to hopefully making them a more regular part of my schedule as the year progresses.

If you're interested in reading The Signal and the Noise, it's available at Amazon.com and many other retailers. I also have a copy of it in my office that I would love to loan out. Send me an email if you want to borrow it!