Why assumptions are important when designing
Contents
What are assumptions in design?
Examples of assumptions when designing an app
How to use assumptions in a design project?
3 examples of testing assumptions
What are assumptions in design?
An assumption is something you believe to be the case with little or no proof. Almost the opposite of a fact. Facts are based on evidence. Assumptions are not.
Assumptions are often based on gut, personal ideas, opinions and biases. This makes them pretty risky when used to design on the back of.
Let’s say the project I am working on is a cooking app that shows users recipes based on what ingredients they have at home. And for this project I want to design the onboarding flow when users sign up. Here are a few examples of possible assumptions when designing this:
users will be at home when using the app so they can go and check their kitchen easily to see what ingredients they have
users want to add ingredients into the app during onboarding to see their final recipes
users go shopping once a week so we will need to ask them to add their ingredients every single week
users will have very similar ingredients each week so they won’t need to add ingredients every single week
These assumptions I have identified will impact how I design the onboarding flow or the rest of the experience for the recipe app. If these assumptions are incorrect. Then I will be designing this app based on incorrect data. How likely do you think the app will succeed if I have designed it based on incorrect assumptions?
For example if I take the example that users only go shopping once a week, I may design the app to only prompt users to input their ingredients once a week. And if they have gone shopping twice that week. The recipes I will show them won’t have updated to include the second set of ingredients, so the app will no longer be useful. So users will stop using it. And yes, sometimes assumptions can end up being true. But if you’re building an entire app or designing an entire flow, do you want to leave this to chance?
With all of this said. Sometimes we will have to design based on assumptions. As there will be times where we don’t have access to data or insight. In these scenarios we will have to TEST these assumptions and prove or disprove them with data. Therefore this design project will become an EXPERIMENT. We will run the experiment and the results will show us whether the assumption was correct or incorrect.
Here’s 3 examples of how to test the assumption:
Let’s use the example from before: Users only go shopping once a week.
1- I can create an experiment where I add a CTA at the top of the home screen which says “I want to add more groceries” This can remain on the screen at all times and we can test to see if users tap on this once a week or more often.
2- Another experiment can be during the onboarding we ask users how often they go shopping and give them options to select.
3- Or we don’t even have to do a test within the app. We can send users a survey and ask them how often they go shopping a week!
Once we have the results from the test we can move ahead will full steam and build more variations of the app with this new information in mind.
Running experiments based on assumptions allow us to learn. We are provided with more data with each experiment. The end result of these experiments isn’t to prove you were right. It is to learn! Learn what works and what doesn’t. Then take these new learnings and design further.
Different types of assumptions
You can have assumptions at different stages of the design project. Here are two of the more common stages:
At the start when trying to identify what problems users may be having.
In the ideation phase when you have assumptions of what solutions will solve the problem.
It’s common to have a whole load of assumptions at both of these different stages. Knowing how to pick the right assumption to move forward with is a very important part of using assumptions. As say if you have the list I mentioned above. How do you know which one to experiment with first? What if you only have time for 1 experiment? Which will you pick?
I will cover this in my next blog post which is all called ‘Picking the right assumption’.
If you have any questions around this topic. Let me know and I will make sure I cover them in the next blog post!
