Mary is the most gifted student a science teacher could hope for. She laps up any and all information given to her, with her specialist field being the electromagnetic spectrum, colour, and the way humans perceive different wavelengths of light. She knows everything there is to know about colour – the possible wavelengths of visible light, the biological structures of the rods and cones which respond to that light, and the way the neural circuits connect up as the brain interprets each wave.

Unfortunately for Mary, she has never seen any colours. Not because she is blind, but because she has been raised entirely in a black and white room. She has simply never been exposed to colour.

Let’s get fruity

This is where I go out on a limb. Until now, I don’t think I’ve really said anything new. I’ve simply taken what has become reasonably well-established dogma in the “traditional” canon and applied it to science practicals. I hadn’t seen anyone else do that so I thought I would give it a crack. However, prepare for things to get a little bit fruity as I try out a new idea.

Traditionalists are big on knowledge (1). As I discussed (based entirely on other people’s hard work and research) in part 2, knowledge is what enables us to think with any kind of complexity about a given subject. Without knowledge about something, we cannot think about it.

So what about our student Mary? Can she be said to possess all the knowledge there is to know about colours and about light?

Frank Jackson, the author of this thought experiment, argues not. Because when Mary steps out of the room she was raised in and into the vibrant and polychromatic world which we inhabit, surely she learns something new: she learns what it is like to see colours. There is a new piece of knowledge which she acquires.

This thought experiment, along with others like the Chinese Room, The Chinese Nation and Philosophical Zombies, are arguments designed by philosophers to counter the charge that the human brain is like a computer – that it is a purely physical device (2). The argument goes that if Mary knows everything physical that there is to know, the brain must be something different, must contain states which cannot be explained in a purely physical way (3). I am certainly no expert in this, and many of the arguments fly right over my head, but the principle for teaching is pretty clear:there are some types of knowledge which can only be acquired through experience.

I don’t really see how this could be argued with. How could anyone say that “a student can have knowledge of what silver crystals forming on a copper wire look like” without ever having seen them? Or at least having seen crystals before. And silver before. And copper wire before.

I could teach students that magnesium combusting in air releases a bright white light, so bright it hurts to look at it, and a grey smoke that billows off the material. And sure, they could memorise that, and probably understand it. But on a very basic level they would have to put that into the context of something they had already experienced. And on a more sophisticated level: do we really think that, upon observation of said combustion, they do not learn what it is like to observe magnesium burning?

To put the problem into the language of cognitive science: if a student can describe the process of the combustion of magnesium, would that knowledge transfer if they were walking down the street two weeks later and saw a bright white light with grey smoke? Would they say “ah! that must be some magnesium combusting!” Maybe yes, but probably not (4).

So there may well be something that can only be taught through real world, hands on experience. I know that as a self-confessed traditionalist, those aren’t really the kinds of word I should be using; but I think it fits just the same.

Mary in action

But here is the rub. Let’s say Mary had a brother called Barry. Barry was also raised in a black and white room. But Barry wasn’t such a good student. He didn’t listen when being taught about colours. He didn’t read any of the black and white text books available to him. He doesn’t know nearly as much as his sister about colours.

When Barry is released to the world he certainly learns something. Just like his sister, he learns what it is like to see colour. But will his experience have the same richness? Mary will be able to instantly assimilate her new knowledge into pre-existing conceptual structures within her mind. Synapses will fire and thought will automatically spring to the front of her consciousness. Her experience will be deepened by her background knowledge of what light is, how it works and how it behaves. Barry however, will have a far shallower appreciation. Sure, it will still probably be a wonderful and striking experience. But will it strike the same note?

I suppose a more immediate example involves myself and an English-teacher friend going to see a hitherto undiscovered Shakespeare. I quite like Shakespeare and would probably enjoy the play. But probably not in the same way that my friend would. The converse is also true, and my experience of watching a new demo or some bizarre physical occurrence might be wildly different to theirs.

So I think I’ve regained my traditionalist street cred. This is all about knowledge, and it is about how we gain new knowledge and how our pre-existing knowledge influences the experience of gaining new knowledge. It doesn’t have to be as arcane as Mary the Super Scientist. It could just be a student looking at cells under a microscope, or watching the temperature change as wax melts. The experience matters, because it is knowledge itself.

Chanuka sameach and merry Christmas!

Introduction: are we wasting our time? – part 1

The Cognitive Science of Practical Science – part 2

Thinking Scientifically – part 3

Do Science Practicals Boost Engagement? – part 4

Mary the Super Scientists – part 5

Teaching Practical Skills: If You Aren’t A Science Teacher, Leave Me Alone – part 6

Conclusion – part 7

(1) Andrew Old published this just today

(2) For further reading I recommend anything by John Searle, especially Mind: A Brief Introduction or The Mystery of Consciousness.

(3) This doesn’t mean that the brain is somehow – God forbid – a spiritual device. See (2) further reading. I also think that each of these thought experiments contain important thinking points for teachers. Perhaps a blog for another time.

(4) See here for a primer on transfer

Advertisements