What does testing test?

Standards are all the rage in school these days. By standards, naturally, we mean test scores. Weeks and months are taken up every year in every public school to prepare for, take, and recover from standardized tests. The results of the tests determine funding, rankings, college admissions and scholarship opportunities. The results of the tests are clearly very important. What about the meaning, though?

What does a test measure? Learning? Potential? Based on the use of the results, both of those seem to be true. Did you learn what the school sought to teach you this year? Do you have the potential to succeed at our university?

The truth is, the test measures nothing but the number of correct answers given to the questions on the test. Only by demonstrating or assuming a correlation between this and something else can the test measure that other thing.

As an analogy, take a classic mercury thermometer. It measures temperature, right? Wrong. It measures the volume of mercury in the tube. The only reason we can determine temperature is because thousands of experiments have been done to correlate volume with temperature, then the thermometer was calibrated with lines to allow the rest of us to read that correlation without going through the math.

Back to school testing. There are studies and correlations out there for testing. A lot of work has been done to validate some of them. At the same time, most of us never worry about that. We take test scores as absolute measures of something (usually learning) and make decisions based on that information.

I have not done the research to be able to speak about the validity of this test or another. I am not in a position to make policy or school board decisions. All I can do is caution all of us to think twice about how we are interpreting and using test results. We are all responsible for how our kids are educated, and it is rarely a good idea to blindly trust others with that task.