The Customer Assumption Trap
As business leaders, we all make assumptions about our customers. We have to. We draw on experience, data, conversations, previous successes, and what we have learned over time to make judgments about what customers need, what they value, and how they will respond. Those assumptions help us make decisions without starting from zero every time a question arises.
That experience is valuable, but it can also create a blind spot. The more familiar we become with our customers, our market, or our organization, the easier it is to believe we already understand the problem in front of us. Before long, “We think this is what customers want” becomes “We know this is what customers want.”
That distinction matters. Even with the best intentions, organizations can make costly customer experience decisions when they move too quickly from what they believe to what they build. By the time an assumption is challenged, it may already be embedded in a new process, service, technology investment, or customer experience.
Design thinking offers a different starting point. Instead of immediately asking “How do we solve this?” it encourages us to first ask “What do we really know?” That small shift creates room for curiosity, learning, and ultimately better decisions.
When Experience Becomes a Blind Spot
We do not always recognize when an assumption is shaping our thinking. What we believe about customers can sound like a reasonable business conclusion: “Our customers care most about price.” “Customers want more choices.” “They won’t use that feature.” “We already know why they’re frustrated.” When statements like these come from people with considerable experience, teams may accept those statements as fact without stopping to ask what evidence supports them.
Even well-supported insights about customers can eventually become outdated. Customer expectations change, markets evolve, new technologies alter behavior, and experiences outside our industry reshape what people expect from ours. What we learned about customers three years ago—or even last year—may not fully reflect what they need today.
Data does not automatically protect us from this problem, either. Even with extensive customer data, organizations can draw conclusions that reinforce what they already believe. A satisfaction score may tell us that something is happening without explaining why, while an isolated customer comment may receive disproportionate attention because it reinforces something the team already believes.
The cost becomes significant when we build solutions around those untested conclusions. We may add features customers do not value, redesign a touchpoint that was never the real source of frustration, or create additional complexity while trying to make an experience easier. The further we travel with the wrong assumption, the more expensive it becomes to turn around.
The Assumption Check
This is where design thinking can make a meaningful difference. Before committing significant resources to a solution, take time to separate what you know about the customer from what you believe to be true. A simple five-step framework can help guide that process: Know, Assume, Learn, Test, Decide.
What evidence do we actually have?
Start with what can be supported by customer behavior, direct research, observation, feedback, or other credible evidence. Be precise about what the evidence tells you and, just as importantly, what it does not tell you.
What are we treating as true without sufficient evidence?
This is often the most revealing part of the conversation. An assumption does not have to be wrong to belong here; it simply means we have not established that it is right.
What do we still need to understand from customers?
Once the gaps become visible, teams can determine which questions matter most. That may mean understanding why customers abandon a process, what creates uncertainty, what they are trying to accomplish, or why their behavior differs from what the organization expected.
What is the simplest way to challenge or validate our thinking?
Testing does not always require a lengthy research initiative. A handful of customer conversations, direct observation, a prototype, frontline employee insight, or a small experiment can sometimes tell us enough to reconsider the direction before making a much larger investment.
What does what we've learned tell us to do next?
The goal is not to keep researching until every uncertainty disappears. The goal is to reduce the uncertainty that matters enough to make a more informed decision and then continue learning as the solution develops.
Consider a company that sees customers abandoning an online application. The immediate assumption might be that the form is too long, leading the team to invest in redesigning and shortening it. But customer conversations could reveal that length is not the primary problem at all; customers are stopping because they do not understand why certain information is being requested or what will happen after they submit it.
That discovery changes the problem from How do we make this form shorter? to How do we create greater clarity and confidence during this process? The eventual solution may require very different changes. More importantly, the organization has avoided spending resources solving a problem customers did not actually have.
Build Curiosity Into the Decision
The Assumption Check is useful during a design thinking exercise, but its greater value comes when this way of thinking becomes part of how an organization operates. Customer-centered organizations do not reserve curiosity for innovation workshops or major transformation initiatives. They bring it into planning meetings, investment decisions, process improvements, and everyday problem-solving.
Leaders have an important role in creating that habit. When someone proposes a solution, ask, “What evidence supports this?” When a team describes what customers want, ask, “What are we assuming?” When everyone appears to agree on the problem, ask, “What haven’t we heard directly from the customer?” These questions are not intended to slow decision-making, but to help prevent organizations from moving quickly in the wrong direction.
There is another leadership challenge here as well. If we want our teams to question assumptions, then we have to be willing to have our own assumptions questioned. People need to know that challenging an established belief, even one held by a senior leader, is an act of learning rather than resistance.
That requires us to become comfortable discovering that we were wrong. In design thinking, being wrong early can be extremely valuable because it gives us information while the cost of changing direction is still relatively low. The goal is not to prove our original idea was right; the goal is to understand the customer well enough to make the next decision better.
Stay Curious Longer
We will never eliminate assumptions from decision-making, nor should we try. Leaders frequently have to move forward without perfect information, and experience helps us make sense of uncertainty. The challenge is knowing when experience is helping us see more clearly and when it is preventing us from seeing something new.
The strongest customer-focused organizations develop the discipline to recognize that distinction. They know what the evidence supports, make their assumptions visible, identify what they still need to learn, and test the questions that carry the greatest risk before making significant investments.
Great customer experiences are not created by organizations that always know what customers want. They are created by organizations willing to keep learning what customers need. Sometimes the most valuable thing a leader can bring to the conversation is not another answer, but the willingness to ask, “What if what we think we know isn’t the whole story?”
