Cognitive Load Theory for
Teachers
Greg Ashman
@greg_ashman
greg.ashman@googlemail.com
gregashman.wordpress.com
I am not a researcher
• I am going to give a simplified version of cognitive load
theory that emphasises its application to teaching
• I will not be discussing intrinsic, extraneous and
germane cognitive load although these terms appear
in the literature. However, you should be aware that
there is a debate surrounding the concept of germane
cognitive load.
[For more information: Sweller, John. "Element interactivity and intrinsic, extraneous,
and germane cognitive load." Educational psychology review 22.2 (2010): 123-138.]
• I will undoubtedly annoy the purist by conflating terms
(e.g. working and short-term memory), conflating
ideas (such as processing and memory) and not
discussing the detail of working memory. Sorry.
Do you think you could remember the following
number for the length of this presentation?
456251
What about this number?
992244782438
The number of items that you can remember like this
is limited (without special training). Miller (1956) first
determined it to be about five to nine items.
[Miller, George A. "The magical number seven, plus or minus two: some limits on our capacity
for processing information." Psychological review 63.2 (1956): 81.]
The bottleneck in your head
Long-term memory
Effectively limitless
Working
Memory
constrained
We can visualise the mind as being
made of different components. Two of
these are working (or short-term)
memory and long-term memory. There
are others e.g. sensory memory. These
are not meant to correspond to specific,
physical regions of the brain.
The bottleneck in your head
Long-term memory
Effectively limitless
Working
Memory
constrained
The working memory roughly corresponds
to what we are conscious of. It is severely
constrained. This capacity varies between
individuals and depends upon what we
are doing with the items.
What is an “item”?
Recalling the number example, imagine that I asked you to
remember six letters for the next half an hour:
GFXTQN
In this case, each letter is an item
Long-term memory
Effectively limitless
Working
Memory
GFXTQN
constrained
What is an “item”?
Imagine that I asked you to remember a different six letters:
SPIDER
This is only one item because you have a concept of “spider”
in your long-term memory.
A key feature of working memory is that its limitations can be
overcome in this way by long-term memory: “chunking”
Long-term memory
Effectively limitless
Working
Memory
constrained
[Ericsson, K. Anders, and Walter Kintsch. “Long-term working memory.” Psychological
review 102.2 (1995): 211.]
Chunking: Knowledge is what
you think with
The bottleneck in your head
Long-term memory
Effectively limitless
Working
Memory
New Learning
constrained
New ideas, information
and procedures must
first be processed in
the working memory
before passing into the
long term memory
The bottleneck in your head
Long-term memory
Effectively limitless
Working
Memory
New Learning
constrained
Too many items to
process leads to
cognitive overload and
learning stops
The bottleneck in your head
Long-term memory
Effectively limitless
Working
Memory
Problem response
constrained
Problem solving, analysis or
any complex task draws on
resources from long term
memory (chunking) to reduce
what needs to be processed in
working memory
The bottleneck in your head
Long-term memory
Effectively limitless
Working
Memory
Problem
response
constrained
If there is little of relevance in
the long term memory then
everything will need to be
processed in the working
memory leading to cognitive
overload
Can you always “just Google it”?
• Perhaps we don’t need students to learn factual
information any more because – should they need
it – they can find it on the internet.
• However, this ‘search’ process will occupy working
memory, leaving less capacity to process and
evaluate what is found.
• In addition, factual information on the internet
cannot be used for chunking (as in the spider
example) in the same way as factual information in
the long term memory.
[For a more detailed discussion: Hirsch Jr, E. D. "You can always look it up—or can
you." American Educator24.1 (2000): 4-9.]
A puzzling phenomena
I often teach maths students how to solve
simultaneous equations like this:
𝑥+𝑦 =5
2𝑥 − 𝑦 = 4
There are two standard approaches that both involve
first finding one of the unknowns, 𝑥 and then finding
the other, 𝑦.
I often find that students launch into the procedure,
find 𝑥 and then stop, thinking that they have finished
the question even though they haven’t found 𝑦.
Why is this? I used to think it was carelessness…
Five-in-the-bed
New
Item
Working
Memory
Five-in-the-bed
New
Item
Working
Memory
I must also
solve for y
Old
Item
This could have
been quite
important...
What is the solution? Practice.
The more the students practice the procedure for
solving simultaneous equations, the more automatic
it will become and the less working memory they will
need to devote to it, freeing up space to remember
key features of the question such as that they must
also find 𝑦.
Think of driving / walking / cycling to work. The first
time that you did this, you had to think about it a
great deal but the procedure has now passed into
your long-term memory and been made automatic,
allowing you instead to daydream…
An example from writing
A student can highlight the grammatical mistakes in a
paragraph that she is given.
However, the paragraphs that she writes herself are
full of the same grammatical mistakes.
Is this carelessness?
It is possible that the process of constructing writing
so occupies the working memory that there is no
space left to check grammar.
Possible solution: A discrete phase of writing
followed by a discrete phase of proof-reading to
separate the two tasks.
Complex Contexts
Reasons for use
• Show why ideas are relevant in the real world.
• Demonstrate the cutting-edge of our subject.
• Potentially motivating.
Examples
- Solving a maths problem about the cost of cars at
different dealerships.
- Creating a news report on the situation in the
Middle East
- Designing and conducting a scientific investigation
Yet
-> Rich contexts increase cognitive load
Complex Contexts
Cognitive load theory predicts:
Two successful strategies
- Teacher guides students through the context in a
highly structured way, pointing out what is important
and what is irrelevant, modelling this thinking
- Simple contexts that are limited in scope are used
early in learning and the teacher guides students
towards more complex contexts
Less successful strategies
- Students are asked to decide upon salient points for
themselves without full teacher guidance e.g.
problem-based learning
Opinion – confusion is not motivating
Kirschner, Sweller and Clark
In 2006, a paper was published by Paul Kirschner, John Sweller
and Richard Clark.
They argued that instructional strategies that avoided the
teacher guiding students through the salient points of a new
concept were in conflict with what we know about cognitive
load.
The strategies that they criticised were:
Constructivist, Discovery, Problem-Based, Experiential, and
Inquiry-Based Teaching
This set the cat amongst the pigeons, generated a number of
responses, led to a conference and even a book.
Opinion: This paper is a must-read for all teachers
[Kirschner, Paul A., John Sweller, and Richard E. Clark. "Why minimal guidance during instruction does
not work: An analysis of the failure of constructivist, discovery, problem-based, experiential, and
inquiry-based teaching."Educational psychologist 41.2 (2006): 75-86.]
Forget theory: I know what works!
Do you?
To borrow from John Hattie, everything works. When we test
an intervention in a school setting we virtually always find a
positive result.
Why?
Because many variables go into teaching. New interventions
are often adopted by enthusiastic teachers who believe in the
intervention. Even in randomised, controlled trials – the gold
standard of such research – it’s pretty hard to ‘blind’ the trial.
Participants – teachers and students – know whether they are
part of the intervention or not and will have expectations
associated with that.
Hattie’s Analysis
• John Hattie’s method is controversial because he groups
together very different kinds of trials and calculates an ‘effect
size’. An effect size of zero would represent no effect and 1
represents a very large effect.
• Because ‘everything works’, Hattie doesn’t simply look for
positive effect sizes, he looks for those above 0.4.
• Instructional strategies that are predicted to be successful by
cognitive load theory fare well in this analysis; the strategies
criticised by Kirschner, Sweller and Clark do not.
• For instance, direct instruction and mastery learning have
high effect sizes (0.59 and 0.57) whereas inquiry-based
learning and problem-based learning have low effect sizes
(0.31 and 0.15)
[Hattie, John. Visible learning: A synthesis of over 800 meta-analyses relating to achievement.
Routledge, 2013.]
Project Follow Through
Unfortunately named.
Hands-up if you have heard of it?
• Origin as an extension of Lyndon Johnson’s 1960s
“Headstart” program for pre-school children
• Idea was to improve teaching of disadvantaged first
graders (hence the “follow through” from pre-school)
• Funding was dramatically cut by congress so instead of
a mass intervention it was decided to run it as a
experiment with different sponsors pitting their
approaches against each other
• It remains the largest and most expensive experiment
in education history
Project Follow Through
Many programs were tested. A large number were
based upon constructivist and ‘child-centred’ ideas
about learning that were (and are!) popular with
educationalists.
A couple of interventions were labelled ‘basic skills
programs’ by the researchers and one of these was
the DISTAR direct instruction program, led by Zig
Engelmann.
Although there was large variation between the
effectiveness of the programs from site to site, the
‘basic skills’ programs were clearly found to be the
most effective, with direct instruction the most
effective of all.
Misconception
Direct instruction was labelled a ‘basic skills’ program
because it emphasised things like basic arithmetic.
This has led to the misconception that direct
instruction is good for teaching basic skills but not for
things like problem solving and that it may harm
motivation.
In fact, direct instruction produced the largest gains in
problem solving skills and in self-esteem in the Project
Follow Through experiment.
Yet proponents of alternative approaches continue to
criticise direct instruction on these grounds and claim
that constructivist or child-centred approaches are
more effective.
Project Follow Through
Carl Bereiter and Midian Kurland put it well:
“When child-centered educators purport to increase the selfesteem of disadvantaged children and yet fail to show evidence
of this on the Coopersmith Self-Concept Inventory, we may ask
what real and substantial changes in self-esteem would one
expect to occur that would not be reflected in changes on the
Coopersmith? Similarly for reasoning and problem-solving. If no
evidence of effect shows on a test of non-verbal reasoning, or a
reading comprehension test loaded with inferential questions, or
on a mathematical problem solving test, we must ask why not?
What kinds of real, fundamental improvements in logical
reasoning abilities would fail to be reflected in any of these
tests?”
Direct instruction did have an effect on these measures.
[Bereiter, Carl, and Midian Kurland. "A constructive look at Follow Through
results." Interchange 12.1 (1981): 1-22.]
Do we get similar results today?
In a 2004 paper, Kroesbergen and colleagues report
on a trial conducted in the Netherlands.
Low-achieving maths students were given either no
intervention, a constructivist intervention where the
students’ own strategies for solving problems were
surfaced and explored, or an explicit intervention
where a teacher directly taught problem-solving
strategies.
Students in both interventions improved but those
given the explicit instruction improved the most.
[Kroesbergen, Evelyn H., Johannes EH Van Luit, and Cora JM Maas. "Effectiveness of
explicit and constructivist mathematics instruction for low-achieving students in the
Netherlands." The Elementary School Journal (2004): 233-251.]
But do they know it better?
The claim is often made that explicit instruction is good
for short-term tests but that strategies where students
have to generate their own ideas produce better longterm gains, more understanding or better transfer to
other types of problem.
This is hard to test and there is a mix of evidence.
However, one interesting paper compared students who
had learnt the scientific principle of controlling variables
by discovering it themselves with those who had been
explicitly taught it. There was no difference in the two
groups’ capacities to analyse science fair posters in a later
test of transfer.
[Klahr, David, and Milena Nigam. "The equivalence of learning paths in early science
instruction effects of direct instruction and discovery learning."Psychological Science 15.10
(2004): 661-667.]
Summary
• Cognitive load theory suggests that we pay
attention to what we are asking students to
process in their working memories; cognitive load
• Early in learning, we can minimise cognitive load by
guiding students; modelling for them what they
should pay attention to and why
• We can also minimise cognitive load by starting in
simple – perhaps more abstract – contexts before
building to complex or more real-life situations
• Cognitive load theory is supported by lab-based
psychology research and its predictions are
confirmed by large-scale educational research
Any Questions?
Greg Ashman
@greg_ashman
greg.ashman@googlemail.com
gregashman.wordpress.com