For years I’ve been meaning to write up a simple technique which makes lessons flow.  I lacked the words until I read Gary Klein’s brilliant book, Sources of Power: How People Make Decisions.  Klein captured what I could not: he described the technique of mental simulation.

Klein spent years studying how experts making decisions.  He shadowed leaders under pressure: pilots and fire chiefs, naval officers and tank commanders.  He is probably best known for this example:

It is a simple house fire in a one-story house in a residential area.  The fire is in the back, in the kitchen area.  The lieutenant leads his hose crew into the building, to the back, to spray water on the fire, but the fire just roars back at them.

“Odd,” he thinks.  The water should have more of an impact.  They try dousing it again, and get the same results.  They retreat a few steps to regroup.

Then the lieutenant starts to feel as if something is not right.  He doesn’t have any any clues; he just doesn’t feel right about being in that house, so he orders his men out of the building – a perfectly standard building with nothing out of the ordinary.

As soon as his men leave the building, the floor where they had been standing collapses.  Had they still been inside, they would have plunged into the fire below.

In this case, although the lieutenant attributed his decision to a ‘sixth sense’ and didn’t even know there was a basement, Klein’s questioning revealed that he had been aware that the fire was much hotter and much quieter than it should have been in a house that size: the lieutenant’s “expectations were violated”.

This example is so arresting that it is the most frequently quoted, but in unpicking how experts think, Klein discusses many other aspects of their practice, and some equally astonishing examples.  A detailed analysis of the USS Vincennes’ attack on an Iranian airliner in 1988, for example, compares the attack to an earlier incident in which the same officer avoided apparently inevitable conflict with Iranian warplanes.  Klein explains how experts use their experience to recognise patterns in situations, how they consider options rapidly and sequentially, and how they use mental simulation to evaluate and refine those options.


Mental simulation

Mental simulation simply means envisaging different ways a situation might play out.  Klein exemplifies it by discussing how a fire officer planned to remove someone from a crashed car.  The doors are crushed and the firefighters’ usual tool (the ‘Jaws of Life’) is unlikely to work in the cramped space.

During his investigation, the commander has noticed that the impact has severed most of the posts holding up the roof of the car.  He begins to wonder if they can lift off the roof and then slide the passenger out rather than fighting their way through the doors.  He tries to imagine how that might be done.  He imagines the roof being removed.  Then he visualizes how they will slide the driver, where rescue workers will stand to support the driver’s neck, how they will turn the driver to maneuver him around the steering column, and how they will lift him out.  It seems to work.  He runs through the sequence again to try to identify any problems but can’t find any.  He has heard that rescues could be made this way, but he had never seen it.

He explains to his crew what they need to do, and the rescue works out as he had imagined.  The only problem is that the driver’s legs become wedged underneath the steering wheel, and additional firefighters have to reach in to unlock his knees.

Klein highlighted the following aspects of a mental simulation:

  • People construct them “the way you build a machine”: they picture the startpoint, they add the next challenge, then the next action, and so on.
  • They’re “not very elaborate”, relying on no more than three factors – like a machine with no more than three moving parts – for example, car, firefighters, driver.
  • People construct them through no more than “six different transition states” – or steps.

The handful of factors and steps we can manage is presumed to be due to the limits of working memory.  Looked at this way, Klein notes, mental simulation “no longer seems easy” as it requires “a lot of familiarity with the task” and the need for “the right level of abstraction”: too detailed and it chews up working memory, too abstract and it provides little help.

Fine for firefighters, what about teachers?

Klein offers examples of mental simulation – successful and unsuccessful – from shipwrecks and war, law and engineering.  I’ve read about its use by sportspeople, visualising moves the night before a game.*  Does this fit teaching though?

A decade ago, as an Assistant Language Teacher in Japan, I stumbled upon mental simulation, realising it could make the difference between a successful lesson and baffled students.  Consider the following scene:

But what were students learning here?  See the end of the post

Logistically, to reach this point, I had to have:

  • Chairs and tables pushed to the side.
  • Students in a circle on the floor
  • Two volunteers, kitted up and positioned
  • All students clear about what was happening

I probably needn’t emphasise that this activity was novel for students, nor that our common language was limited.  So how to make this work?

Mental simulation was a key part of my preparation: sitting over the plan and visualising each successive step.  To give another example:

Japan 2

  • Tables into fours
  • Cards distributed
  • Instructions
  • A model
  • Start playing

Playing it out in my head, I might come across obstacles or delays: students are in an odd number – so where will the two extra students go?  How will students choose who should go first?  I might ask the person nearest the door to begin.  Mental simulation allowed me to anticipate problems and refine the lesson accordingly, or, in meeting an insurmountable obstacle, rework the plan from scratch.

Perhaps the discipline of writing a lesson plan as a new teacher is designed to help address this need.  I’m not sure it does though: it’s too easy, particularly as a novice teacher, to write ‘Students quiz one another’ without thinking through, or mentally simulating the transition: how many students in each group?  How will they move their seats?  Who will give out the quiz papers and when?

I suspect experienced teachers do this unthinkingly, and I also suspect that novice teachers either don’t do it, or they struggle.  Success requires both thinking to mentally simulate the change and a good understanding of the different ‘factors’ – how an approach may play out in a specific classroom  Experienced teachers are also likely to ‘chunk’ ideas: having distributed a task and asked students to pair up hundreds of times, they are likely simply to think ‘start the activity’; for novice teachers ‘handing out papers’, asking students to ‘pair up’ and getting them started represent three separate actions..

So this week’s suggestion: in planning your next lesson mentally simulate the transitions.  Or more importantly, in working with a trainee, ask them to talk you through their mental simulation of the lesson step by step.

Klein’s book is both a great read and full of fascinating ideas about expertise: Sources of Power: How People Make Decisions.

In many ways Klein’s work may seem to conflict with Daniel Kahneman’s, on the limits of our expertise.  This paper, which co-authored by Klein and Kahneman, on the ‘Conditions for Intuitive Expertise’ is fascinating.

The Real Mr Roo offers this example of mental visualisation in sport, from Wayne Rooney: ‘I visualise scoring wonder goals’.

What were students learning?

Picture 1 – Directions: up, down, left right, forward, back.  The two combatants are trying to hit one another with rubber mallets while blindfolded.  Peers are shouting directions (in English), pupils are responding (under pressure).

Picture 2 – Numbers.

* Searched for and failed to find the reference for this.  Remind me please.