Assumptions Are Killing Your User Research
“Assumption mapping is the step at the start of a research project where a team brainstorms what it thinks matters, then designs research to test those guesses. It feels like preparation, and it sets the scope of your discovery on a hunch before you’ve spoken to anyone. This piece covers why that goes wrong, and what to do instead.”
Every team dreams of finding a burning problem, building a product and launching something that changes how people work. Watching an idea turn into something people use is the whole reason for doing this.
The reality is harder. Roughly half of new US businesses close within five years, and 80% of features in the average software product are rarely or never used, according to Pendo's analysis of 615 subscriptions. The most common root cause of startup failure, across CB Insights' analysis of founder post-mortems, is no market need. Nobody wanted the thing.
You might think researchers and design thinkers solved this long ago. Most companies have adopted a methodical customer discovery process as the first step in design. They understand they've to build empathy for users, listen carefully, and design for validated unmet needs. That should identify what users want and improve the odds of success.
Customer discovery does improve those odds. Most companies still take an approach that's compromised before the first interview.
What's assumption mapping?
Assumption mapping is the practice of brainstorming what a team believes will matter to users, debating the relative importance of each belief, then designing research questions to validate or eliminate them. It usually involves post-it notes, journey mapping and a whiteboard.
The flaw sits so early in the process that many teams don't consider it part of research at all. Whether the project runs on user interviews, diary studies or an online survey, the scope of exploration is set in concrete at this stage.
Why is assumption mapping a problem?
It leaves researchers chasing unvalidated directions, driven by anecdotal evidence or a hunch. They walk into user interviews carrying a discussion guide that confines discovery to topics chosen in advance, and confirmation bias does the rest, because a guide built from assumptions keeps finding what it went looking for.
How many teams have failed because their assumptions blinded them to what participants actually prioritise?
Pre-determined priorities lead to pre-determined destinations.
As a profession, we rally together to dissect survey questions and discussion guides looking for hints of leading questions, while ignoring the bias introduced on day one. Rob Fitzpatrick's The Mom Test covers the interview half of this problem thoroughly, and says nothing about the scope decision that precedes it.
The alternative isn't skipping it
Researchers who skip assumption mapping end up scrambling around the edges of a broad scope for weeks or months, narrowing slowly towards what participants care about.
That sounds better on paper, and few teams have that kind of time.
Example of a hypothetical discovery research project timeline.
What's priority mapping?
Priority mapping uses mixed methods research to establish which topics matter most to participants before the research project begins.
Instead of guessing which issues to explore, you measure them. It's the same logic behind customer development, applied one step earlier. That lets you eliminate the topics with least impact, dig into the highest-value ones, make better use of participants' time, and finish ahead of schedule.
Customer Problem Stack Ranking and pairwise comparison surveys make this possible in hours instead of weeks. Run one as the first step of a discovery project and you set your scope on validated priorities instead of a whiteboard exercise.
The surveys find the issues that matter most to users, written in the users' own words. With that upfront you can write better discussion guides and clearer research objectives, and go deeper on the important issues across fewer interviews. The time saved goes back into higher-value work: the strategic project you never got to, or upskilling workshops for internal partners. It also cuts the idea validation cycle considerably.
Replacing assumption mapping with a discovery research tool like OpinionX helps you to set a more focused scope based on validated mixed methods insights from the outset, enabling deeper research in a fraction of the time.
Priority mapping in action
Niamh De Búrca founded SproutPlans, an early-stage startup building a personal finance platform. She had recognised that young digital-first professionals rarely pay for in-person financial advisers.
In February 2021, Niamh decided she needed discovery research with her target audience to understand their pain points, motivations and behaviour around personal finance. The findings would inform the product roadmap, the core value proposition and the positioning. The first step mattered.
SproutPlans hit a common problem. They needed discovery research, and as a young startup they couldn't spend weeks interviewing dozens of people and analysing the data by hand.
Niamh understood that entering interviews with no idea what mattered most would leave her with a wide scope. That approach needs a large volume of participants in lengthy interviews before the biggest pains even appear, let alone get explored properly. There are three mistakes founders make at exactly that point. She also didn't want leap-of-faith assumptions narrowing her interviews too early and causing her to miss something important.
Running the survey first
Niamh ran an OpinionX survey before starting the discovery interviews. It let her collect opinions at scale like a traditional open-ended survey, and because participants voted on each other's answers, it also showed how far each opinion represented the whole group.
She set the survey up to explore what mattered most to young professionals about personal finance, and what their financial focus was over the following three years. She added a handful of sample statements to test her existing hypotheses and to prompt participants to contribute their own.
What it found
The biggest concern among her participants was an inability to find trustworthy financial advice. That statement was submitted by a participant, not by Niamh, and it was voted most important, which validated SproutPlans' original hypothesis about the unmet need around financial advice.
Niamh went into interviews knowing that trust was the primary differentiating factor for her target customers. That focus saved months of research and produced deeper discovery in a much shorter project.
“OpinionX has saved me months in research and building time, along with thousands in costs. I am blown away by the outcome. The OpinionX approach to customer discovery is essential in uncovering true and uninfluenced pain points when searching for product-market fit.”
Data-driven discovery
Next time you prepare for user interviews, think about what assumption mapping does to the outcome.
Where did these assumptions come from?
How would I justify the initial direction of this research to the wider team?
Could better research practice help me prioritise the most impactful issues inside this brief?
When the earliest direction of a project rests on uninformed assumptions, the damage is done before anyone speaks to a user.
Use ranking methods to understand your users' biggest unmet needs, pain points and motivations before the research begins.
Frequently asked questions
What's assumption mapping in UX research?
A workshop practice where a team lists what it believes to be true about its users, ranks those beliefs by importance and risk, then designs research to test them. It typically happens before any participant contact, using post-it notes and a whiteboard.
What's wrong with assumption mapping?
It sets the scope of your discovery before you've any data. Every assumption on the board came from the team, not from users, so the research can only confirm or reject ideas the team already had. Anything nobody in the room thought of stays invisible.
What's priority mapping?
Measuring which issues matter most to your target users before the qualitative research starts, using a ranking survey instead of a workshop. The output sets your interview scope on what participants actually prioritise, and not on what the team guessed.
Does priority mapping replace user interviews?
No. It decides what the interviews are about. You still need qualitative work to understand why a problem matters and what people have tried already. Priority mapping just means you spend those interview hours on the problems that scored highest, instead of discovering the ranking as you go. That sequencing is the Discovery Sandwich.
How long does priority mapping take?
Hours, not weeks. Writing the problem statements is most of the work, and problem brainstorming covers how to generate them. Once the survey is live, results arrive as participants vote, and participants can add statements you missed.
Every two weeks, The Full-Stack Researcher sends one breakdown on the future of user research to over 42,000 subscribers.
Set your research scope on what users rank highest instead of what your team guessed. Every question type and every analysis feature is unlocked on the free tier, capped at 25 participants per survey.