Thursday, 14 February 2008

science of learning



The Science of Learning

As Clive Shepherd writes, "cognitive neuroscientist Dr Itiel Dror of

Southampton University. Itiel is becoming a bit of a celebrity amongst

the e-learning community in the UK as someone who avoids the grand

theories of learning and concentrates instead on practical tips based

on what we know about the brain and how it works (assuming we really

do and this I must place on trust)."

Of course, the sceptical side of me says that this is something like

saying that so-and-so can tell us best how to win an auto race because

he's a mechanic. There is, indeed, a distinction between knowing how

something works and knowing how best to use it.

Reading through the points in thsi summary, they seem sort of right,

but not exactly right. Let me clarify them.

* The brain is a machine with limited resources for processing the

enormous quantity of information received by the senses. As a

result, attention is extremely selective and the brain must rely

on all sorts of shortcuts if it is to cope effectively.

My response: no criticism of this; it seems to be about right.

* Teachers/designers can adopt two strategies to reduce the risk of

learners experiencing cognitive overload: provide less information

(quantitative approach) or take much more care about how this

information is communicated (qualitative approach).

Well, you see now, this approaches the problem not from the nature of

the brain but rather from the nature of the information. And when we

look at the information as nothing more than a pile of stuff to be

processed by the brain, then sure, these are the ways to deal with it.

But the other way to look at it is to, as promised, look at it from

the perspective of neuroscience. What does the brain do in cases of

cognitive overload? This is important because, if we know how the

brain will adapt, we know how to shape our information (if at all).

This is the subject of the next few points, so I'll continue.

* It is easier for a person to focus their intention on the desired

point if there is minimal noise (other information) surrounding

it. Reducing noise also reduces context, so a balance needs to be

struck.

I assume he meant 'attention' and not 'intention'. In any case, I'm

sure there are all kinds of tests proving this, but I will point out

that the nature of the subject is a much more significant variable.

People are able to focus on things even in the most extreme of

circumstances if they are sufficiently interested. That's how you can

have kids playing video games even while the house is burning down

around them (I guess that's the sort of 'context' that would be

important). By contrast, if you aren't really interested in what you

are doing, the least amount of noise distracts you.

We know this because (as was just stated above) we know that the brain

is extremely selective and filters out stuff that isn't important.

Perspective matters. From the teacher's point of view, the content

(lessons or curriculum) is constant, while the level of background

noise is the variable. From the point of view of the learner, however,

the content is also variable. That's why you get two very different

interpretations of the same phenomena.

* Overload can be reduced by grouping items/steps (what Itiel calls

'chunking'). Grouping can be accomplished by placing

people/objects/events into categories, or by compressing a number

of procedural steps into one, automatic action. Visually you may

separate items by space, size or colour. Learners will naturally

employ grouping as a strategy, although they may do this

inappropriately and the process requires effort. Better for the

designer/teacher to present material ready grouped.

This is a good strategy and one I have recommended elsewhere to help

people write academic essays easily and proficiently (and without

notes, but I digress). I find it interesting, though, that he used the

DE design term 'chunking'. Maybe reading something other than

neuroscience?

Yes, there are different types of groups. Groups that make sense

conceptually, especially if linked to a larger framework, are better

(I would add that colour is rarely, if ever, a part of such a

framework).

But is it better for the teacher to present the material already

grouped? How does that follow? If the intent is to have the student

learn the information (ugh, bad terminology) then we must ask, is it

the groups that aide remembering and understanding, or the process of

grouping that does this? If it's the latter, then presenting the

information already grouped may help the teacher remember, but will do

nothing for the student.

Because, as I noted above, it is better if the groups align with a

pre-existing conceptual framework, it is better then if the student

does the grouping, because that way the process allows the student to

connect, in an organized way, new knowledge with existing knowledge.

* A side effect of grouping is that once the action is completely

familiar (that old 'unconscious incompetence' phase), the

individual finds it hard to explain how they do it; they lose

control over the process because it has become automatic (so old

hands may not always be the best teachers?). Grouping is essential

to our functioning, but there are obvious dangers, i.e. unhelpful

stereotyping.

Here there seems to be a confusion between grouping, as in the sense

of classifying different perceptual entities into types, and grouping,

as in the sense of combining several activities into one. Now this

isn't necessarily bad (I have said elsewhere that learning to read is

similar to learning to ride a bicycle) but can be very misleading

unless carefully explained.

I think it would have been better to present them separately.

There are mental processes that can become automatic. Add 1+1 for

example. One of these processes is 'categorization'. You look at a

bunch of things and automatically associate some with the others,

based on habitually formed patterns of association. In some cases,

such as grouping people by colour, this sort of automatic association

can be inappropriate.

There are also mental processes that constitute sequences of steps.

The steps involved in a logical derivation, for example. So a process

that actually involves multiple steps may be performed by an

experienced logician as though it were only one step (I called this

'skipping steps' in logic class and complained bitterly about it.

"It's obvious," said the professor. "Whaaaa?" I responded).

These are very different phenomena that are essentially the result of

the same neural process but which instantiate very differently and

need to be approached very differently. Kind of like the way the

steering used to recover from a spinout may be exactly the same as the

steering required to navigate a hairpin curve. Sure, it's the same

motion. But you would describe the two events very differently.

1. Individuals use top-down processing to reduce overload. This draws

automatically on their past experience of the particular context,

existing knowledge and intelligence and avoids them having to

evaluate all new information from the bottom up. An example would

be how people can easily read a sentence in which the letters in

each word are jumbled up.

Yes. But...

This is not 'top down' processing as traditionally understood.

There is a very large difference between inferring something on the

basis of similarity to a prototype (that is, apttern recognition), and

inferring something based on a general principle or rule. By 'top

down' we typically mean the latter. But when describing character

recognition, as in the example, we are describing the former.

I would also be wary of building the (Darwinian?) intent into the

process. People use pattern recognition. It reduces information

overload. But it is not necessarily true that people use pattern

recognition in order to reduce information overload. People use

pattern recognition because that's how neural networks work. Perhaps

evolution directed us in this way, perhaps it did not. Either way, our

use of pattern recognition in a particular circumstance is not caused

by some such intent. It occurs naturally, as though by habit.

* Designers/teachers need to take account of the way in which the

information is likely to be encoded and processed - it's not 'what

you teach' but 'what is learned'.

Except... it is very misleading to say that it's 'encoded'. Otherwise,

yes, there is a large distinction between what the teacher teaches and

what the learner learns (which is why information-theoretic and

transmission-theoretic theories of learning are wrong).

* Different parts of the brain specialise in different tasks.

Individuals can engage in more than one task at the same time, as

long as each uses a different part of the brain.

Of course, these parts of the brain form dynamically and according to

experience and circumstance, so there's no telling in advance, or in

general, what processes occupy the 'same' part of the brain and what

processes do not.

That's why I can read and write while listening to loud music, as I'm

doing now, while my father couldn't.

* It's a myth that we only use 5-10% of the brain - we use it all.

Correct.

* The brain continues to change throughout our lives, even though we

stop adding new brain cells in our early 20s. Some parts of the

brain are relatively hard-wired (through nature or nurture), some

very plastic. It makes sense to concentrate in recruitment on

finding those people with hard wiring which suits the job, because

no amount of training will sort the problem out later. (Itiel did

not go into detail about those capabilities which tend to be

hard-wired and those which are more plastic - this is clearly

important.)

The main part - that neural nets are plastic - is true and important.

It is also true that some parts are pretty much hard-wired -- good

thing, too, or our hearts wouldn't beat and our eyelids wouldn't

blink.

But as to how much this carries over into learning or into life skills

- this is very controversial. I can certainly agree that there are

people with currently existing wiring that may be more or less suited

to the job. That's no more controversial than saying people learn

different things. But to say that these capabilities are hard-wired is

much more questionable.

1. As you grow older the hard-wired capabilities persist - the most

learnable capabilities go first.

This is demonstrably false. For otherwise there would be no

incontinence in old people.

1. Language is more than just a means for expressing thought - in

many ways it is thought. If a person is not exposed to any

language in early years, then by the age of seven they are

incapable of learning it.

I doubt that this is uniquely true of language - it is probably true

for any pattern set. Can a person become fluent in mathematics despite

never having been exposed to numbers. Can a person become a musician

having never been exposed to tone and melody?

People who have not specialized in the nature of language typically

take language as a given - some sort of folk-psychological

representation of Chomskyian generative grammar. And then suppose that

this then must be the nature of thought.

Even if language is thought - which i would not grant for a second -

we still know nothing about the nature of thought if we do not agree

on the nature of language. Which we probably most emphatically do not.

* The two sides of the brain really do have different functions (I

thought this was just pop psychology). The left brain concentrates

on language and analytical skills; the right has the spacial

abilities. The left side of the brain controls the right side of

the body and vice versa. The left and right sides of the brain do

not interact physically.

They do interact, through something called the 'corpus callosum'. But

yes, the two sides of the brain do specialize, as observed. That said,

to my knowledge, this specialization is not hard-wired.

* The size of a person's brain is not an indicator of intelligence.

Within the normal variation of human brains, that is. My poor cat,

with her cat-sized brain, will never reach human intelligence. But

she's still very cute.

* 20% of your blood is in the brain.

Which stresses the importance of nutrition to brain function.

* You never lose anything from long-term memory, just the ability to

retrieve it. Retrieval is a function of how you encode memories /

the number of links you provide.

Well, yeah, in the sense that the connections that constitute the

long-term memory are basically permanent, more or less. But you don't

'retrieve' memory the way you retrieve a book from the bookshelf (even

though it feels that way).

'Retrieval' (properly-so-called) is a case of pattern recognition -

and the less salient a pattern becomes in the mind, the less likely it

is to be associated with a current perception.

* Working memory consists of 7+/-2 items (again I thought this was

pop psychology).

Yes. And there's that 'grouping' again, in a third guise. We can

remember things that are more than 7 words long by recognizing them as

coherent patterns. That's why I can remember something like 'Turn

right at the third light and then left at the second stop sign, then

go four blocks' even though it consists of 18 words (and 70 letters).

or 1-800-857-2020 even though it's 11 digits long.

What we put into working memory first depends on pattern recognition.

* To reduce cognitive overload, take out every word or picture that

is not necessary or relevant to your learning goals. Even then,

don't deliver more than the learner can handle (presumably by

modularising the learning).

This is effective only at the very gross level, and not particularly

useful as you get into finer details (and more precise definitions of

'necessary').

I have seen studies, for example, showing that a slide show with

bullet points is more easily remembered than a slide show with the

same bullet points and animated graphics.

I expect, though, that the placement of the 'NRC' logo in the corner

of the same slides would not have an impact either way.

I also expect that the removal of 'unnecessary' letters in the bullet

points would actually hinder memory. Fr exmpl, rmving mst f th vwls.

Thy r nt necsry in the snse that we cn stl rd the sntnce, bt they hlp

wth the grping.

So - better advice would be something like - present material that

accords (perhaps with some cognition) with patterns that will already

be familiar to the learner.

* Provide the learning when it is needed, not before.

Sure. But why? This isn't determined by whether it is necessary or

not, but rather, by whether it is salient or not.

* Be consistent in the manner of your presentation, e.g. the

interface.

This can actually be distracting, taken to extremes. That's why

documentaries switch from having a person talk to showing some nature

scenes with a voiceover to interviewing some other person.

* Be consistent in the level of your presentation, i.e. not too

complex, not too simple. Try to work with homogeneous groups;

better still personalise the learning.

Yes, but again, why? I would argue that this facilitates pattern

matching .

1. Engage the learner by grabbing their attention, allowing them to

determine their progress, providing constructive feedback,

introducing an element of excitement/surprise.

Again, this doesn't follow from the presentation above. What has

happened here is that some hackneyed (and vague) pedagogical tips have

been attached to some discussion of neural function, without a clear

linkage between them.

* Be careful of allowing the learner too much control over the

learning process if they don't have the metacognitive skills, i.e.

they don't know what they know and what they don't know, nor how

best to bridge the gap. Ideally help learners to increase their

metacognitive skills, i.e. learning how to learn.

This has utterly nothing to do with the brain theory discussed above.

If the content has more to do with attention than, say, distraction,

then taking control away from learners, even in areas where they do

not have skills, may cause more harm than good.

And what are the metacognitive skills. What is 'learning how to

learn', for example?

* Providing the learner with control over pace and allowing them to

go back and repeat any step is important.

Same point.

* The learning benefits by being challenging. Performance targets,

rewards and competition can increase the degree of challenge,

perhaps through the use of games.

And again, same observation. This doesn't follow from what has been

stated above. Sure, it's good advice (what Seymour Papert and James

Paul Gee call 'hard fun'). But why is it good advice. What else can we

learn about this piece of advice. What kind of games, for example (see

Aldrich on this).

Anyhow, those are my thoughts based on this reading of Shepherd's

article. I also read a bunch of Dror's publications online and

certainly have no quibble with his neuroscience. I just think that the

study of teaching and learning involves more than just neuroscience,

and that there are areas of complexity and potential confusion Dror


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