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Thursday 16 May 2013

Thoughts on Cognitive Load Theory and its implications for teaching



Now, let me first make it clear that I am not a psychologist and I have no formal psychology qualification. I have been an educator, including a head teacher, for a number of years. So, I have gleaned what I think I know and understand from reading and tweeting. I was interested in a method of teaching called Direct Instruction (DI). I could not find anyone who used this system as very fully described on the internet. A simple Google search will give lots of references. A few folk have put their finger into this pie and a guy called Englemann has written a book, extracts of which are available.

It seemed to me that critical to the validity of Direct Instruction is the accuracy of a cognitive psychology theory called Cognitive Load Theory (CLT). So, a little diversion which will allow me to see what I can explain about CLT. I might even add a couple of diagrams - but YouTube has some nice, simple videos explaining CLT as well.

CLT postulates two memory systems in the human brain, One is called working memory, there are other terms. This is what we use to temporarily remember information. If I ask you to read the following once and then repeat it immediately, you are using working memory. So here goes:

01923 460172

Look away and repeat the number.

Whether you were successful at reproducing the number or not you have shown that you have a thing that allows you to remember some numbers. If you do nothing else then the number will disappear and you will gradually forget it.

But, if I tell you a few things about the number

It is a telephone number
The first part, 01 923, is the STD code for Watford
The second part, six numbers, 460    172 are the rest of the number
What I also done is chunked the number for you. More about chunking, later. Nothing to do wit pineapple chunks, by the way!

Then you will find you are more able to remember more of the number. That assumes you have remained interested enough to keep playing along with me. if you have great. If not, can’t win ‘em all!

If I get you to repeat the number, preferably in a fixed pattern like, 01 923 460 172, then after a few repeats the number will be easier to remember. What you are doing is moving the number into the second memory system, called Long Term Memory. If you want to divert into how we can effect better memorisation then Spaced Learning will be your cup of tea. Stay with me for a little longer please.

Working memory can retain data for up to 60 seconds. The actual time is less important than the fact that it is a short time. Also distractions can shorten this time or impact on the accuracy of the data retained in working memory.

Working Memory seems, also, to be the place where we manipulate the data stored there. Where we do our thinking! Thinking, in a very simplistic model, is comparing one thing to another. Is it bigger or smaller; is it the same or not the same. Lots of simple comparisons to decide in some data forms a part of that thing or this thing. We recognise the telephone number as being a telephone number, rather than, say, the price of a pint of beer, in working memory.

To move this data, the telephone number, into long term memory involves, essentially tagging the data with already existing schema, memory maplets I will call them, existing already in long term memory. I tried to help you do that transfer process by telling you that it was a telephone number. I assume you already have a map in your brain that says a particular number has the format of a telephone number. I told you it was Watford STD code. You probably have two scheme, one for STD code and one for Watford, that you can readily attach the telephone number to.

Why are schema important?

Two reasons: First, we need schema to attach data to so that it can be stored in long term memory. So we can remember it.

The second reason is that we can include schema in our working memory. They seem to be able to be used inside working memory and that allows us to process information at a higher level. We simply cannot hold the amount of data in our working memory that would be needed to understand without being able to use the schema we have in our long term memory.

To see the dramatic effect that having access to schema can be you just have to realise how you are understanding the words that you are currently reading. You don’t read each letter to understand the word. You take it in as a whole because you have a scheme for that word. Much faster and means you can actually read a lot faster than you think you can!

It also explains why, for those who can spell, why a words just *looks* wrong. Your schema for words includes the shape of the word. An incorrectly spelled word will be the wrong shape! Nicely, my computer also underlines the word in red which draws my attention to the word. Shape tells me it is wrong, or sometimes right - silly computer, and then I use working memory to decide where the word is wrong.

I need a cup of tea now so the rest of this blog will have to wait. Just  make sure you get schema built in your brain for working and for long term memory. We will need some of the details to see what these Direct Instruction folk are saying.

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