How doctors handle uncertainty and what UX designers and educators can learn
Realizing the importance of precision in language for navigating ambiguity and improving decision-making
A few years ago, a doctor friend explained that my chronic IBS was a “diagnosis by exclusion,” a fancy way of saying they'd ruled out every other possible cause and landed on this… uncertainty. The phrase struck me as a convoluted way to avoid saying "I don't know," and it frustrated me. I understood the words, but not the reluctance to admit to uncertainty. Why not just say it outright?
Fast forward to today: my IBS has flared up again, and that phrase keeps echoing in my brain. So, I opened my text editor, prepared to unleash a takedown of the expression and the lengths smart people go to avoid admitting they don’t have answers. But something unexpected happened as I dug deeper.
Shades of “I Don’t Know”
At first, I was ready to mock this term and all the other linguistic acrobatics we use to dodge “I don’t know.” To get my creative juices flowing, I used ChatGPT as an Idea DJ, asking it to generate a list of other ways professionals say “I don’t know” without actually saying it.
Here’s what it produced:
Sounds like a boundary, but really it's a dressed-up "I don't know."
“I’ll have to look into that further.”
A polite way of deferring the answer until later (which may or may not happen).
“It’s an area that warrants further investigation.”
A fancier way of implying uncertainty while sounding like a scientist.
“There are many factors at play here.”
By acknowledging complexity, they avoid giving a definitive answer.
“It depends.”
A classic move—this shifts the focus to the variables, instead of admitting ignorance.
“We’re still gathering data.”
A great way to defer an answer without actually having one.
“There’s not enough evidence to make a conclusion at this time.”
A scientifically responsible way to say, “I don’t have an answer.”
“We’ll need to take a holistic approach to this."
Which really just means, "I can’t pinpoint it."
At first, this list only fuelled my frustration. But then, something clicked. I realized I often use these terms too, and they serve a valuable purpose. In fact, many of them aren’t about dodging the truth at all. They offer a subtle commitment to finding the answer or at least acknowledging complexity.
Not all “I don’t knows” are created equal
Saying “I don’t know” can be powerful. It shows confidence, humility, and honesty. But in some contexts, a straight-up “I don’t know” can come off as apathetic or passive, especially when people are looking for direction or expertise. That’s when these other phrases come into play. They aren’t just linguistic disguises for ignorance—they’re signals of action or curiosity.
Take “Let me look into that further.” It doesn’t simply admit you don’t have the answer; it suggests that you’re committed to finding one. "We’re still gathering data" tells the person you’re still in the process of discovering something new, not just shrugging it off.
So even though I started off hating “diagnosis by exclusion” for being so hands-off, looking at it in the context of other expressions gave me a new perspective. There’s a beauty to having so many shades of “I don’t know”—each with its own specific twist on the lack of knowledge and what you’re willing to do to close the gap.
Applying “diagnosis by exclusion" to UX design
This realization got me thinking: maybe “diagnosis by exclusion” isn’t so far removed from what we do in UX research.
Just like doctors who don’t always have a clear answer right away, UX researchers and designers often have to navigate uncertainty. When faced with ambiguous user behaviour or unclear feedback, our process often involves ruling out hypotheses, eliminating pain points, and continuously refining the problem.
Let’s say you’re trying to figure out why users are dropping off at a certain point in a flow. You can’t pinpoint the exact cause immediately, but you can start eliminating potential issues through A/B testing, user interviews, or heuristic evaluations. In this sense, UX research is often a process of exclusion, much like diagnosing a medical condition. We work through the data we have, eliminate the factors that don’t fit, and ultimately refine our understanding.
The beauty of this approach in UX is that it allows you to get closer to the truth without necessarily having a definitive answer right away. Iteration and testing become your tools for "diagnosing" the user experience. In this way, UX research and design mirror the methodical nature of diagnosis by exclusion: testing, ruling out, refining.
Teaching through uncertainty as an approach for educators
For educators, this analogy applies just as well. Think about when you’re helping a student who is struggling with a concept. You don’t always know exactly what’s going wrong at first. Instead, you try different teaching methods, experiment with various explanations, and rule out the less effective approaches.
This is a powerful teaching tool because it not only helps students arrive at answers but also teaches them how to approach problems in a methodical way. Critical thinking becomes a practice of working through uncertainty, not avoiding it.
“Diagnosis by exclusion” for educators can mean showing students that it’s okay not to have immediate clarity, and what matters more is the process of elimination, inquiry, and reflection. It helps students learn how to navigate ambiguity—something they’ll encounter often in real-world problem-solving.
Nuanced language in communicating uncertainty
The way we frame uncertainty matters. As a UX designer, telling a client or team "I don’t know" might feel uncomfortable, but using the right language can change the tone entirely. Saying, “We’re still gathering data” or “We need to explore that further” implies forward movement and curiosity. It’s not just about admitting uncertainty; it’s about how you frame it.
In education, the same principle applies. Telling a student “I don’t know” can be discouraging, but saying “Let’s figure this out together” signals engagement. As educators, we have to guide learners through uncertainty and problem-solving, modelling how to embrace not knowing as a pathway to learning.
Embracing uncertainty as a strength
What started as frustration with the jargon of “diagnosis by exclusion” ended as a reminder that uncertainty is unavoidable in any complex problem-solving field. In UX design, education, and even medicine, how we navigate and communicate that uncertainty is what defines our ability to move forward.
Next time we face the unknown, maybe the best response isn’t just “I don’t know” but a thoughtful reflection on what comes next. After all, it’s not about knowing everything—it’s about knowing how to find the answer.
