5 ways to measure UX return on investment

For those new to the qualitative research space, there’s one question that’s usually pretty tough to figure out, and that’s the question of how many participants to include in a study. Regardless of whether it’s research as part of the discovery phase for a new product, or perhaps an in-depth canvas of the users of an existing service, researchers can often find it difficult to agree on the numbers. So is there an easy answer? Let’s find out.

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Here, we’ll look into the right number of participants for qualitative research studies. If you want to know about participants for quantitative research, read Nielsen Norman Group’s article.

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Getting the numbers right

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So you need to run a series of user interviews or usability tests and aren’t sure exactly how many people you should reach out to. It can be a tricky situation – especially for those without much experience. Do you test a small selection of 1 or 2 people to make the recruitment process easier? Or, do you go big and test with a series of 10 people over the course of a month? The answer lies somewhere in between.

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It’s often a good idea (for qualitative research methods like interviews and usability tests) to start with 5 participants and then scale up by a further 5 based on how complicated the subject matter is. You may also find it helpful to add additional participants if you’re new to user research or you’re working in a new area.

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What you’re actually looking for here is what’s known as saturation.

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Understanding saturation

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Whether it’s qualitative research as part of a master’s thesis or as research for a new online dating app, saturation is the best metric you can use to identify when you’ve hit the right number of participants.

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In a nutshell, saturation is when you’ve reached the point where adding further participants doesn’t give you any further insights. It’s true that you may still pick up on the occasional interesting detail, but all of your big revelations and learnings have come and gone. A good measure is to sit down after each session with a participant and analyze the number of new insights you’ve noted down.

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Interestingly, in a paper titled How Many Interviews Are Enough?, authors Greg Guest, Arwen Bunce and Laura Johnson noted that saturation usually occurs with around 12 participants in homogeneous groups (meaning people in the same role at an organization, for example). However, carrying out ethnographic research on a larger domain with a diverse set of participants will almost certainly require a larger sample.

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Ensuring you’ve hit the right number of participants

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How do you know when you’ve reached saturation point? You have to keep conducting interviews or usability tests until you’re no longer uncovering new insights or concepts.

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While this may seem to run counter to the idea of just gathering as much data from as many people as possible, there’s a strong case for focusing on a smaller group of participants. In The logic of small samples in interview-based, authors Mira Crouch and Heather McKenzie note that using fewer than 20 participants during a qualitative research study will result in better data. Why? With a smaller group, it’s easier for you (the researcher) to build strong close relationships with your participants, which in turn leads to more natural conversations and better data.

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There's also a school of thought that you should interview 5 or so people per persona. For example, if you're working in a company that has well-defined personas, you might want to use those as a basis for your study, and then you would interview 5 people based on each persona. This maybe worth considering or particularly important when you have a product that has very distinct user groups (e.g. students and staff, teachers and parents etc).

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How your domain affects sample size

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The scope of the topic you’re researching will change the amount of information you’ll need to gather before you’ve hit the saturation point. Your topic is also commonly referred to as the domain.

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If you’re working in quite a confined domain, for example, a single screen of a mobile app or a very specific scenario, you’ll likely find interviews with 5 participants to be perfectly fine. Moving into more complicated domains, like the entire checkout process for an online shopping app, will push up your sample size.

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As Mitchel Seaman notes: “Exploring a big issue like young peoples’ opinions about healthcare coverage, a broad emotional issue like postmarital sexuality, or a poorly-understood domain for your team like mobile device use in another country can drastically increase the number of interviews you’ll want to conduct.”

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In-person or remote

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Does the location of your participants change the number you need for qualitative user research? Well, not really – but there are other factors to consider.

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• Budget: If you choose to conduct remote interviews/usability tests, you’ll likely find you’ve got lower costs as you won’t need to travel to your participants or have them travel to you. This also affects…
• Participant access: Remote qualitative research can be a lifesaver when it comes to participant access. No longer are you confined to the people you have physical access to — instead you can reach out to anyone you’d like.
• Quality: On the other hand, remote research does have its downsides. For one, you’ll likely find you’re not able to build the same kinds of relationships over the internet or phone as those in person, which in turn means you never quite get the same level of insights.

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Is there value in outsourcing recruitment?

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Recruitment is understandably an intensive logistical exercise with many moving parts. If you’ve ever had to recruit people for a study before, you’ll understand the need for long lead times (to ensure you have enough participants for the project) and the countless long email chains as you discuss suitable times.

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Outsourcing your participant recruitment is just one way to lighten the logistical load during your research. Instead of having to go out and look for participants, you have them essentially delivered to you in the right number and with the right attributes.

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We’ve got one such service at Optimal Workshop, which means it’s the perfect accompaniment if you’re also using our platform of UX tools. Read more about that here.

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Wrap-up

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So that’s really most of what there is to know about participant recruitment in a qualitative research context. As we said at the start, while it can appear quite tricky to figure out exactly how many people you need to recruit, it’s actually not all that difficult in reality.

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Overall, the number of participants you need for your qualitative research can depend on your project among other factors. It’s important to keep saturation in mind, as well as the locale of participants. You also need to get the most you can out of what’s available to you. Remember: Some research is better than none!

Introduction

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User research is invaluable, but in fast-paced environments, researchers often struggle with tight deadlines, limited resources, and the need to prove their impact. In our recent UX Insider webinar, Weidan Li, Senior UX Researcher at Seek, shared insights on Efficient Research—an approach that optimizes Speed, Quality, and Impact to maximize the return on investment (ROI) of understanding customers.

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At the heart of this approach is the Efficient Research Framework, which balances these three critical factors:

• Speed – Conducting research quickly without sacrificing key insights.
• Quality – Ensuring rigor and reliability in findings.
• Impact – Making sure research leads to meaningful business and product changes.

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Within this framework, Weidan outlined nine tactics that help UX researchers work more effectively. Let’s dive in.

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1. Time Allocation: Invest in What Matters Most

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Not all research requires the same level of depth. Efficient researchers prioritize their time by categorizing projects based on urgency and impact:

• High-stakes decisions (e.g., launching a new product) require deep research.
• Routine optimizations (e.g., tweaking UI elements) can rely on quick testing methods.
• Low-impact changes may not need research at all.

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By allocating time wisely, researchers can avoid spending weeks on minor issues while ensuring critical decisions are well-informed.

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2. Assistance of AI: Let Technology Handle the Heavy Lifting

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AI is transforming UX research, enabling faster and more scalable insights. Weidan suggests using AI to:

• Automate data analysis – AI can quickly analyze survey responses, transcripts, and usability test results.
• Generate research summaries – Tools like ChatGPT can help synthesize findings into digestible insights.
• Speed up recruitment – AI-powered platforms can help find and screen participants efficiently.

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While AI can’t replace human judgment, it can free up researchers to focus on higher-value tasks like interpreting results and influencing strategy.

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3. Collaboration: Make Research a Team Sport

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Research has a greater impact when it’s embedded into the product development process. Weidan emphasizes:

• Co-creating research plans with designers, PMs, and engineers to align on priorities.
• Involving stakeholders in synthesis sessions so insights don’t sit in a report.
• Encouraging non-researchers to run lightweight studies, such as A/B tests or quick usability checks.

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When research is shared and collaborative, it leads to faster adoption of insights and stronger decision-making.

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4. Prioritization: Focus on the Right Questions

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With limited resources, researchers must choose their battles wisely. Weidan recommends using a prioritization framework to assess:

• Business impact – Will this research influence a high-stakes decision?
• User impact – Does it address a major pain point?
• Feasibility – Can we conduct this research quickly and effectively?

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By filtering out low-priority projects, researchers can avoid research for research’s sake and focus on what truly drives change.

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5. Depth of Understanding: Go Beyond Surface-Level Insights

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Speed is important, but efficient research isn’t about cutting corners. Weidan stresses that even quick studies should provide a deep understanding of users by:

• Asking why, not just what – Observing behavior is useful, but uncovering motivations is key.
• Using triangulation – Combining methods (e.g., usability tests + surveys) to validate findings.
• Revisiting past research – Leveraging existing insights instead of starting from scratch.

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Balancing speed with depth ensures research is not just fast, but meaningful.

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6. Anticipation: Stay Ahead of Research Needs

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Proactive researchers don’t wait for stakeholders to request studies—they anticipate needs and set up research ahead of time. This means:

• Building a research roadmap that aligns with upcoming product decisions.
• Running continuous discovery research so teams have a backlog of insights to pull from.
• Creating self-serve research repositories where teams can find relevant past studies.

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By anticipating research needs, UX teams can reduce last-minute requests and deliver insights exactly when they’re needed.

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7. Justification of Methodology: Explain Why Your Approach Works

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Stakeholders may question research methods, especially when they seem time-consuming or expensive. Weidan highlights the importance of educating teams on why specific methods are used:

• Clearly explain why qualitative research is needed when stakeholders push for just numbers.
• Show real-world examples of how past research has led to business success.
• Provide a trade-off analysis (e.g., “This method is faster but provides less depth”) to help teams make informed choices.

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A well-justified approach ensures research is respected and acted upon.

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8. Individual Engagement: Tailor Research Communication to Your Audience

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Not all stakeholders consume research the same way. Weidan recommends adapting insights to fit different audiences:

• Executives – Focus on high-level impact and key takeaways.
• Product teams – Provide actionable recommendations tied to specific features.
• Designers & Engineers – Share usability findings with video clips or screenshots.

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By delivering insights in the right format, researchers increase the likelihood of stakeholder buy-in and action.

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9. Business Actions: Ensure Research Leads to Real Change

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The ultimate goal of research is not just understanding users—but driving business decisions. To ensure research leads to action:

• Follow up on implementation – Track whether teams apply the insights.
• Tie findings to key metrics – Show how research affects conversion rates, retention, or engagement.
• Advocate for iterative research – Encourage teams to re-test and refine based on new data.

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Research is most valuable when it translates into real business outcomes.

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Final Thoughts: Research That Moves the Needle

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Efficient research is not just about doing more, faster—it’s about balancing speed, quality, and impact to maximize its influence. Weidan’s nine tactics help UX researchers work smarter by:

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✔️  Prioritizing high-impact work
✔️  Leveraging AI and collaboration
✔️  Communicating research in a way that drives action

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By adopting these strategies, UX teams can ensure their research is not just insightful, but transformational.

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Watch the full webinar here

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Natalie and Lulu have forged a unique team culture that focuses on positive outputs (and outcomes) for their app’s growing user base. In doing so, they turned the traditional design approach on its head and created a dynamic and supportive team. 

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Natalie, Director of Design at Hatch, and Lulu, UX Design Specialist, recently spoke at UX New Zealand, the leading UX and IA conference in New Zealand hosted by Optimal Workshop, on their concept of “radical collaboration”.

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In their talk, Nat and Lulu share their experience of growing a small app into a big player in the finance sector, and their unique approach to teamwork and culture which helped achieve it.

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Background on Natalie Ferguson and Lulu Pachuau

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Over the last two decades, Lulu and Nat have delivered exceptional customer experiences for too many organizations to count. After Nat co-founded Hatch, she begged Lulu to join her on their audacious mission: To supercharge wealth building in NZ. Together, they created a design and product culture that inspired 180,000 Kiwi investors to join in just 4 years.

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Contact Details:

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Email: natalie@sixfold.co.nz

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LinkedIn: https://www.linkedin.com/in/natalieferguson/ and https://www.linkedin.com/in/lulupach/

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Radical Collaboration - How teamwork makes the dream work 💪💪💪

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Nat and Lulu discuss how they nurtured a team culture of “radical collaboration” when growing the hugely popular app Hatch, based in New Zealand. Hatch allows everyday New Zealanders to quickly and easily trade in the U.S. share market. 

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The beginning of the COVID pandemic spelled huge growth for Hatch and caused significant design challenges for the product. This growth meant that the app had to grow from a baby startup to one that could operate at scale - virtually overnight. 

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In navigating this challenge, Nat and Lulu coined the term radical collaboration, which aims to “dismantle organizational walls and supercharge what teams achieve”. Radical collaboration has six key pillars, which they discuss alongside their experience at Hatch.

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Pillar #1: When you live and breathe your North star

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Listening to hundreds of their customers’ stories, combined with their own personal experiences with money, compelled Lulu and Nat to change how their users view money. And so, “Grow the wealth of New Zealanders” became a powerful mission statement, or North Star, for Hatch. The mission was to give people the confidence and the ability to live their own lives with financial freedom and control. Nat and Lulu express the importance of truly believing in the mission of your product, and how this can become a guiding light for any team. 

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Pillar #2: When you trust each other so much, you’re happy to give up control

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As Hatch grew rapidly, trusting each other became more and more important. Nat and Lulu state that sometimes you need to take a step back and stop fueling growth for growth’s sake. It was at this point that Nat asked Lulu to join the team, and Nat’s first request was for Lulu to be super critical about the product design to date - no feedback was out of bounds. Letting go, feeling uncomfortable, and trusting your team can be difficult, but sometimes it’s what you need in order to drag yourself out of status quo design. This resulted in a brief hiatus from frantic delivery to take stock and reprioritize what was important - something that can be difficult without heavy doses of trust!

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Pillar #3: When everyone wears all the hats

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During their journey, the team at Hatch heard lots of stories from their users. Many of these stories were heard during “Hatcheversery Calls”, where team members would call users on their sign-up anniversary to chat about their experience with the app. Some of these calls were inspiring, insightful, and heartwarming.

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Everyone at Hatch made these calls – designers, writers, customer support, engineers, and even the CEO. Speaking to strangers in this way was a challenge for some, especially since it was common to field technical questions about the business. Nevertheless, asking staff to wear many hats like this turned the entire team into researchers and analysts. By forcing ourselves and our team outside of our comfort zone, we forced each other to see the whole picture of the business, not just our own little piece.

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Pillar #4: When you do what’s right, not what’s glam

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In an increasingly competitive industry, designers and developers are often tempted to consistently deliver new and exciting features. In response to rapid growth, rather than adding more features to the app, Lulu and Nat made a conscious effort to really listen to their customers to understand what problems they needed solving. 

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As it turned out, filing overseas tax returns was a significant and common problem for their customers - it was difficult and expensive. So, the team at Hatch devised a tax solution. This solution was developed by the entire team, with almost no tax specialists involved until the very end! This process was far from glamorous and it often fell outside of standard job descriptions. However, the team eventually succeeded in simplifying a notoriously difficult process and saved their customers a massive headache.

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Pillar #5: When you own the outcome, not your output.

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Over time Hatch’s user base changed from being primarily confident, seasoned investors, to being first-time investors. This new user group was typically scared of investing and often felt that it was only a thing wealthy people did.

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At this point, Hatch felt it was necessary to take a step back from delivering updates to take stock of their new position. This meant deeply understanding their customers’ journey from signing up, to making their first trade. Once this was intimately understood, the team delivered a comprehensive onboarding process which increased the sign-up conversion rate by 10%!

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Pillar #6: When you’re relentlessly committed to making it work

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Nat and Lulu describe a moment when Allbirds wanted to work with Hatch to allow ordinary New Zealanders to be involved in their IPO launch on the New York stock exchange. Again, this task faced numerous tax and trade law challenges, and offering the service seemed like yet another insurmountable task. The team at Hatch nearly gave up several times during this project, but everyone was determined to get this feature across the line – and they did. As a result, New Zealanders were some of the few regular investors from outside the U.S that were able to take part in Albirds IPO. 

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Why it matters 💥

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Over four years, Hatch grew to 180,000 users who collectively invested over $1bn. Nat and Lulu’s success underscores the critical role of teamwork and collaboration in achieving exceptional user experiences. Product teams should remember that in the rapidly evolving tech industry, it's not just about delivering the latest features; it's about fostering a positive and supportive team culture that buys into the bigger picture.

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The Hatch team grew to be more than team members and technical experts. They grew in confidence and appreciated every moving part of the business. Product teams can draw inspiration from Hatch's journey, where designers, writers, engineers, and even the CEO actively engaged with users, challenged traditional design decisions, and prioritized solving actual user problems. This approach led to better, more user-centric outcomes and a deep understanding of the end-to-end user experience.

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Most importantly, through the good times and tough, the team grew to trust each other. The mission weaved its way through each member of the team, which ultimately manifested in positive outcomes for the user and the business.

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Nat and Lulu’s concept of radical collaboration led to several positive outcomes for Hatch:

• It changed the way they did business. Information was no longer held in the minds of a few individuals – instead, it was shared. People were able to step into other people's roles seamlessly. 
• Hatch achieved better results faster by focusing on the end-to-end experience of the app, rather than by adding successive features. 
• The team became more nimble – potential design/development issues were anticipated earlier because everyone knew what the downstream impacts of a decision would be.

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Over the next week, Lulu and Nat encourage designers and researchers to get outside of their comfort zone and:

• Visit customer support team
• Pick up the phone and call a customer
• Challenge status quo design decisions. Ask, does this thing solve an end-user problem?

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