Comparing average temperatures from around the world is useful if you want to compare this single attribute. It works because you are comparing a single entity across a large sample size.
However, if you want to compare a particular student’s achievement against an average student, this is NOT very useful. Most importantly because of the complexity that makes up success. And because of this complexity, I argue that there really is no ‘average student’. Take a look at the chart to the right as an example. Comparing a single measure like knowledge or reading doesn’t take into account the entire learning profile. Each student is unique — each one with strengths and challenges.
The complex world of learning can’t be quantified by a simple average. There are think-tanks and critics who are quick to jump to a single measure to find a story that says we’re not succeeding or using a measure to compare one school against another. They use singular events like a one time FSA score or a provincial exam grade to compare students or schools against each other to make an argument about our educational demise.
Averages just don’t work that way.