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CAF lesson plan

2. CAF lesson plan

CAF: Consider All Factors

This lesson plan is for the CAF lesson workcard

The Factors Involved.

CAF is a crystallization of the process of trying to consider all the factors in a situation.

This thinking operation is essentially related to action, decision, planning, judgment, and coming to a conclusion.

People naturally assume that they have considered all the factors, but usually their consideration is limited to the obvious ones. Turning CAF into a deliberate operation switches attention from the importance of the factors to looking around for all the factors. Clearly it is difficult to consider all the factors, so in the teaching situation consideration can be limited to the ten most important factors (or any other number), or the lesson can be taught in terms of:

  • the factors affecting oneself

  • the factors affecting other people

  • the factors affecting society in general.

This gives the lesson structure.

The emphasis of the lesson is on the factors that have been left out in a decision, plan, etc. In doing a CAF, students try to ensure that all important factors are listed. In looking at each other's thinking, students try to spot which factors have been neglected. The CAF may be applied to one's own thinking as well as to the thinking of others: "What factors have I left out here?''

CAF differs from PMI in that PMI is a reaction to an idea whereas CAF is an exploration of a situation before coming up with an idea. The two do sometimes overlap because some of the factors that have to be considered obviously have a plus or minus aspect. The intention with a CAF is to be as complete as possible and to consider all factors rather than looking at them in terms of favorable or unfavorable factors.

See student workcard for an example of what happened when a big city's traffic planners failed to do a CAF and left out a very important factor.

It could be argued that CAF should come before PMI, since CAF includes PMI. But the PMI is the easier lesson to teach, so it comes first.

The CAF lesson is a difficult one to teach because it is difficult to try and consider all factors. The emphasis must therefore be on what has been left out. For instance, each group tries to find factors that have not been put forward by the "designated group."


(see Practice section in workcard)

Normally practice items 1, 2 and 3 are used one after the other. But for any one of these the teacher may choose to substitute items 4 or 5. The students should work in groups.

Practice Item 1. A husband and wife go to buy a used car for their family.

The groups spend 3 minutes trying to find factors which the couple buying the car has left out. The teacher then asks one group to give its findings and the other groups can then add other factors.


  • Their children may not like the car.

  • Although they can afford to buy the car they may not be able to afford to run it if the fuel consumption is high.

  • The car may not fit their garage (if they have one).

Practice Item 2. Do a full CAF on the factors involved in choosing a career.

Here the groups consider all the factors involved in choosing a career. They should spend 5-7 minutes. At the end of this time the teacher designates one group to give its output and then the other groups and individuals can add further points. If possible and if there is time, the points can all be listed and each group can pick out the four points it considers to be the most important.

Practice Item 3. An inventor has invented a breakfast pill which is very tiny but contains all the food and vitamins you need. After you have eaten the pill you do not feel hungry for five hours. Should this pill be allowed. What are the factors involved?

This is a quick item. The teacher gives the starting signal and in the next two minutes each group must pick out as many factors as it can. The groups who say they have picked out the highest number then give their output to which the others can add. This is a race to pick out the most factors in the shortest time.


  • What would happen to all the farmers, food manufacturers and shops?

  • There would be no dishes to wash.

  • You could have your breakfast while going to work.

  • Breakfast would not be very enjoyable and people need enjoyment.

  • Would people's stomachs shrink?

  • If the pill were useful for breakfast wouldn't it be useful for every meal? Would this be safe?

Discussion and further practice

Open a discussion with the class, acting as individuals rather than groups.

  • Is it easy to leave out important factors?

  • When is it most important to consider all the factors?

  • What is the difference between PMI and CAF?

  • What happens when other people leave out certain factors?

  • Do you need to consider all factors or only the most important ones?

The groups look at the learning points given in the student's workcard. They are asked to pick out the principles they think most important. The groups can also be asked to criticize any one of the principles or to create a principle of their own.

These de Bono Thinking Lessons are free to use by parents, guardians and teachers. (This means on this website, or to print and use in home or in the classroom. Not for further distribution or commercial use). 

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