Even in Vygotsky’s time (1925-35) people knew (or he did, in the Soviet Union) that to get a useful reading of where a child was at in intellectual development you needed information not just of what they could do now but of what they’d soon be able to -- the Zone of Proximal Development or ZPD, for which one of my Canadian students, invited to publicise it with a bumper sticker, wrote ‘Zee Pee Dee Doo Dah, Zee Pee Dee Day’ (though Canadians usually say ‘zed’).
And how did you know about a child’s ZPD since it would be entered only in the future? a good indication was what he/she could manage now with just a bit of help.
Something of the spirit of Vygotsky’s insight needs to get into assessment in schools. In my own marking, where the strictness of the mark scheme didn’t prevent it, I tried to consider the student’s trajectory as well as his position in a moment in time. Two students with B- might be very different in terms of their promise and I wanted my marking to reflect that -- ideally by indicating both.
Judging promise is an inescapably subjective business. But I was paid as a professional, and what it means to be that is that you’re trusted to exercise judgement. I imagined myself placing a bet: who would you bet on to be the best writer in, say, three years’ time? The assessor’s situation, given he/she is properly qualified (educated and experienced), should be more like that of a wise boss hiring someone: all you can go on is what you know and can find out at present -- but on that basis you make your best guess.
So, who would you bet on for success in future? The person’s life chances are in your hands, but better that, I would judge, than in the robotic grasp of some mechanical scheme. The privilege of exercising judgement, though, brings with it the responsibility of constant effort to get better -- first by seeing how your bets work out, and second by betting alongside colleagues and discussing your reasons in what, in the CSE examination teachers' meetings in West Yorkshire c.1975, we used to call agreement trials.