top of page

Identify your assumptions

Assumptions are helpful for getting your project started. They are your best guess about something or someone. They act as useful guides while you discover the broader shape and size of your work. But it’s important to know where your assumptions lie and to move them from being theories to being evidenced. This will make sure that you base all your decisions on the real world. 

When to do it

Do this after you have produced your problem statement. Prioritise and test your assumptions as soon as you can. Monitor and review them as your work evolves.

How to do it

You should:

  • list all of your assumptions starting with your problem statement and what you know about your users

  • map them onto a 2x2 grid showing importance and how certain you are about them

  • prioritise your most important and uncertain assumptions

  • test and validate your assumptions by gathering more evidence to reduce uncertainty

Try this activity

This activity will give you a prioritised list of assumptions and a plan for how to validate them.

Time, space and materials

  • 30 minutes

  • any space with a wall, sticky notes, paper and pens for a face-to-face event

  • or for a remote event use a video conference and online whiteboard that will take the place of the wall and enable participants to add and move online ‘sticky notes’


  • display your work so far on the wall, including your problem statement and what you know about your users

  • create a large 2x2 grid (drawn or use tape) at least 1 metre wide and tall or make a large grid using your online whiteboard

People to include

  • your team

  • any number of people

  • a facilitator to give the instructions


The purpose of this activity is to say what your assumptions are and think about how to validate them. An assumption is something that you suspect is likely or probable, but do not have proof of it being true yet.

  1. Everyone should review the work that has been done so far. Remind yourselves what you have found out. Write any assumptions you made on sticky notes. Write 1 assumption per sticky note. You have 10 minutes.

  2. Stick your assumptions to the wall. As you put them up, read other people’s notes and group together any similar ones. You have 2 minutes.

  3. One person should volunteer to give a summary to everyone else about all the assumptions that have been reported. You have 2 minutes.

  4. Label the grid. Top: ‘important’. Bottom: ‘unimportant’. Left: ‘uncertain’. Right: ‘certain’.

  5. Everyone should now take some of the assumptions and move them across to the grid. Think about how important the assumption is – does it have a big or small impact on the work? Think about how certain the assumption is – how confident are you that it is true?. As you are placing them, think about where others have placed their assumptions. Discuss them as you move. You have 5 minutes.

  6. You will now decide how to validate the most important and most uncertain assumptions. Everyone should choose an assumption in that corner of the grid and say what you could do to prove it. Write your idea on a sticky note. Be as specific as possible. Mark it with a V – for validation - in the top left hand corner. Stick your ideas to the wall. When you have finished one, move on to another. Make sure that between you, all of the assumptions in that corner are covered. You have 2 minutes.

  7. In turn, each person should explain their proposed validation method to everyone else. You have 1 minute each. After each person has spoken, discuss, edit and agree the validation method.

  8. You now have a visual map of your assumptions and a plan for how to validate the highest priority ones.


  • change the time you need depending on how many assumptions you have

  • consult an expert, like an analyst, to find evidence that proves or disproves your assumption

Next steps

Further reading

Find out more about this topic by searching the internet for:

bottom of page