The original version of this article was published on October 17th, 2017.

My teaching was steeped in the philosophy of assessment for learning, even before hearing of the term. My classroom was characterised by oral questioning, written tests (peer-marked, self-marked or marked automatically) and, when appropriate, mock examinations.

In other words, my classroom was data-rich. I had information on each pupil's scores, progress and expected grades -- and, crucially, any discrepancies between their expected grades and their actual grades in the mock exams.

But, and I think this is an important caveat, I used other kinds of data too. For example, as I wrote in my article 37 Features Of Outstanding ICT And Computing Lessons, one criterion is that pupils keep looking at the clock on the wall, because they want to get to a certain point in their work before the end of the lesson. They have a sense of urgency. (Note: see the end of this article for how to acquire an updated version of that ‘Outstanding features’ article.]

Another thing I kept notes on was the quality of the questions pupils asked in the lesson. For example, a question like "Wouldn't it be more efficient to use a Do...Until loop in this situation?" is of a different order to one like "Is it ok to print on both sides of the paper?"

I have grave misgivings in general about the quantification of everything, and in particular about big data, which I summarised in an infographic, in my article entitled Big Data Infographic:

I recently came across a great quote while reading an article in the New Yorker by the writer Rebecca Solnit:

My own task these past twenty years or so of living by words has been to try to find or make a language to describe the subtleties, the incalculables, the pleasures and meanings—impossible to categorize—at the heart of things. My friend Chip Ward speaks of “the tyranny of the quantifiable,” of the way what can be measured almost always takes precedence over what cannot: private profit over public good; speed and efficiency over enjoyment and quality; the utilitarian over the mysteries and meanings that are of greater use to our survival and to more than our survival, to lives that have some purpose and value that survive beyond us to make a civilization worth having. From Woolf’s Darkness: Embracing the Inexplicable, by Rebecca Solnit in The New Yorker Magazine.

I think that expression, “the tyranny of the quantifiable” is brilliant: succinct, accurate and apposite. It should be adopted as a common-sense cautionary measure by all people and agencies for whom the only valid data is that which contains numbers.

And by the way, for a really good set of alternative sets of data see the book Dear Data, which I mentioned in this article: The Importance Of Reading In Education Technology: 3 Books To Read And Recommend.