It’s time somebody looked (at least in the public eye) at some of the demographics and policy/practices and how they may or may not relate to achievement (in terms of WKCE scores).
First a very brief less in the art of correlation. We can take any two pieces of information and mathematically determine whether or not there is a pattern…a correlation. The mathematical tool is the correlation coefficient. It provides a number ranging from -1 (perfect inverse correlation, as X increases, Y decreases) to +1 (perfect correlation, as X increases/decreases, so does Y). Then, all we need to do is apply some statistics based on the size of our data set to determine whether or not the correlation is significant (statistically speaking). For this exercise we looked at the 95% level of confidence, which means that there would be 5% or less chance that the correlation observed resulted from chance alone.
Much more on the oft-criticized WKCE, here.