Assumptions will occur throughout the life of any project, and can often help expedite a process. Though, the most important thing to remember about an assumption is the verification. An easy way to remember this is through the simple phrase, "Trust, but verify."
Create a grid consisting of at least three columns, and as many rows as your team has assumptions.
The first column should consist of "Assumptions." These assumptions are the theories that each team member presumes within their project pitch.
The second column should consist of techniques for "Testing" these assumptions. These techniques should be agreed upon by the team as accomplishable tasks that can result in a conclusion with a confident degree of certainty.
The third column should consist of results that prove "Validation" upon testing these assumptions. These are the idealized results based on the evidence acquired from testing. When a majority can agree that validity is evident, then confidence can grow for an idea.
While not necessary, you may want to make your list a dynamic document throughout the life of a project. As such, it is typical to include a fourth "Results" column to organize which assumptions had been tested, and whether or not they had passed the validity test. While this is not necessary, it helps organize what you've accomplished and illustrate why you've moved forward on an assumption. These can be illustrated as, a "+" for a success, "-" for failure, and a "0" for an untested assumption.
Not all assumptions can be validated. Restraints including time, finances, and other impeding factors can prevent testing; and that's alright. The most important thing to remember is that an assumption placed in the presence of mind, untested or not, is half the battle for success. It means the team recognizes the importance of validation and will keep that in mind to-and-through a project.
A set requirement of time isn't typical for this process because it can be used as a dynamic document. Though, it can take 30 minutes to an hour to get the process going and have everyone begin submitting their assumptions.
Customers prefer X.
100 x A/B Copy test.
+75% clicked X.
The color X encourages engagement.
100 X Heat Mapping test.
+75% screen time.
The price of X is too high.
10 X In-depth Interviews.