"We have to unlearn a lot of things, and that, i mean, we have to do this individually," she says. "Our work as teachers is idiosyncratic, and it's also subjective." We try and imagine that we can have some objective measure of learning, but something as complicated as learning can't be reduced to an algorithm,. It can't be reduction to rows in a spread sheet. Every teacher is different, all students are different, which means we have to approach the student themselves - not just as a series of rows and columns and spread sheets.