Stephen Downes

Be sure to have a look at the 'multiple measures of data' graphic in this post. It is a four-circle Venn Diagram identifying four corresponding measurement metrics and how they interact. Of course, once you admit these dimensions of measurement, what is to argue against a variety of other measurements - nutrition intake, for example, local crime rate, perhaps, or per-student computer budget - into the same sort of calculation. Of course, if you do that, then you have made a mash of the idea that you can nicely and neatly measure school achievement - and you can't have that, can you?