Why You Should Always Pair Quantitative and Qualitative UX Research

By Philip Burgess – UX Research Leader

In UX research, there’s an old saying: Numbers tell you what is happening, but stories tell you why. This is why—whenever possible—I run quantitative and qualitative research in parallel.

I’ve seen this combined approach consistently lead to better insights, stronger stakeholder buy-in, and more impactful design decisions. Here’s why it works so well.

1. Quantitative Shows the Scope, Qualitative Reveals the Cause

Quantitative data—like click-through rates, task success rates, or survey scores—tells you what is happening and how widespread an issue may be. But numbers alone rarely tell you why the problem exists.

That’s where qualitative research comes in. By observing users, listening to their feedback, and digging into their thought process, you uncover the root causes behind the numbers.

Example: A task success rate of 45% tells you there’s a problem. Observing five users struggling with unclear navigation labels tells you exactly what to fix.

2. Triangulation Builds Confidence

When you run both methods, you can validate findings from one with data from the other. This triangulation strengthens your recommendations and makes it harder for stakeholders to dismiss your insights as anecdotal or irrelevant.

If 70% of survey respondents report frustration with checkout, and your usability tests reveal that users can’t find the shipping cost until the final step, you have both the evidence and the explanation.

3. Faster Decision-Making

Running studies in parallel means you can present a more complete picture to stakeholders in one go, instead of coming back weeks later with “the rest of the story.” This speeds up alignment and gets changes into design and development faster.

4. Stakeholder Appeal Across Audiences

• Data-driven leaders respond well to charts, metrics, and statistical significance.

• Designers and product teams often connect more deeply with user quotes, session recordings, and observed behaviors.

When you bring both to the table, you engage every audience in a way they understand and value.

5. It Future-Proofs Your Insights

Product teams often return to research findings months—or even years—later. Having both qualitative and quantitative data in the report makes it easier to re-interpret, re-use, or re-analyze insights without re-running the study.

When You Can’t Run Both

While it’s ideal to pair them, sometimes timelines or budgets don’t allow it. In those cases:

• If you start with quantitative, leave room for follow-up interviews to explore unexpected trends.

• If you start with qualitative, try to run a quick survey afterward to validate your findings at scale.

Bottom Line

Quantitative tells you what is happening. Qualitative tells you why.By running both in parallel, you get the full story, make stronger recommendations, and increase the odds your work will lead to meaningful change.