August 8, 2019
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How many participants do I need for qualitative research?

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.

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.

Getting the numbers right

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.

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.

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

Understanding saturation

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.

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.

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.

Ensuring you’ve hit the right number of participants

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.

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.

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).

How your domain affects sample size

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.

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.

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.”

In-person or remote

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.

  • 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.

Is there value in outsourcing recruitment?

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.

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.

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.

Wrap-up

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.

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!

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The other side of the conversation: 3 reasons why UX researchers should take a turn as a participant

Lately, I’ve found myself sitting in the participant’s chair at the UX research table more and more and it’s been an eye-opening collection of experiences. As UX researchers, we’re definitely not our users, but we are someone else’s. We use products, services and tools too! I’ve recently discovered that participating in user research not only helps out a fellow UXer with their qualitative research, but has also helped me grow my skills.

Here are 3 reasons why you should try being a participant for yourself.

1. Build empathy for the participant experience 🫶

Having facilitated hundreds of UX research sessions over the years, I didn’t think I would be as nervous as I was going in as a participant! When we design our research sessions we don’t often give our participants a heads up on what we’re going to talk about because we don’t want to influence them for one, but truly not knowing what to expect made me feel slightly jittery. Before and at the beginning of these experiences, I felt quite unprepared. I wasn’t expecting to feel that way.

During these sessions I often found myself wondering things like: Were my answers detailed enough? Will my responses be kept confidential? (I could never seem to remember if that had been covered in the introduction!). I worried that I wasn’t giving helpful responses or if I was talking too much. When misunderstandings arose in the conversation, I felt responsible and I was kicking myself for not communicating clearly enough!

As a participant, I completely lost track of time during the session and developed an entirely new appreciation for timekeeping as a facilitator! I could have talked well beyond the scope of the interview timeframe and needed to be kept on track.

I also very quickly discovered that thinking aloud is a lot harder to do than it sounds. It’s not a simple matter of verbalizing your thoughts as they happen. You have to think them, process them, decide how to verbalize them and then talk – all while someone (often a complete stranger) is looking at you expectantly and eagerly. It’s awkward and it feels weird. And look, it is widely acknowledged that it’s challenging and unnatural, but I didn’t fully appreciate or understand that until I was required to do it myself in a research environment.

Did I experience some of these thoughts and feelings because I’m a UX researcher and I know what the other side looks and feels like? Maybe. It’s certainly possible and I’d be remiss if I didn’t call out this potential bias, but I do feel that having done this I now have a greater capacity to empathize with the participant experience. I’ve now been on the receiving end of the introductory spiel (and tuned out during it!), I’ve now got first-hand experience with the on-the-spot answering of those questions we carefully craft and I’ve scrambled for words when I’ve been asked to explain why I said what I said.

These experiences have taught me that there’s a good chance the participant is just as nervous as I am and that a little reassurance or confirmation of usefulness goes a very long way. I’ve learned that regardless of the skill or experience of the researcher, interview questions can be super confusing and hard to answer. Having questions rephrased and being told that what I shared was helpful made me feel significantly more comfortable and able to think clearly and open up more - therefore providing more value to the researcher.

I’ve also been itching to find out what happened next after the sessions ended. Was I helpful and in what way? Where did the insight I provided lead? I’ve learned that while we walk away with more questions, so might our participants and what can we do about that? We’re so busy, but stopping for a moment further down the track if/where possible to reach out and say ‘Hey, I just thought you might like to see what we did with all that great information you shared with us’ might be nice. It’s not always practical or possible and sometimes we have to wait until the thing goes live, but it’s food for thought.

2. Learn from other researcher’s styles 📚

Every UX researcher is different and we all have our own approaches and styles. As a notetaker for other researchers, I’ve always enjoyed having the opportunity to observe them in action, but somehow experiencing it as a participant felt different in the best possible way. It felt more immersive. Perhaps it was because I didn’t have to think about anything else or observe the participant’s reactions and was able to absorb every second of that experience as it was happening to me rather than in front of me.

I participated in a usability testing session with two researchers - one facilitating and one taking notes - and the notetaker was so unobtrusive and quiet that I completely forgot they were there! They said a quick hello at the beginning of the session and then sat back behind me and blended in with the furniture and didn’t make a sound until they piped up with a question at the very end. Note taking is such a grossly underrated UX research skill. There’s a lot to think about, a lot to avoid thinking about (e.g., jumping into solution right there in the session) and of course we have to be mindful of the potential impact of our behavior on the participant, but this went beyond stifling disappointment or resisting the urge to speak. This was a dignified and seamlessly elegant note taker existence unlike anything I have ever seen.

In other sessions as a user interview participant I was delighted when researchers injected multiple moments of humor into those previously mentioned introductory spiel snooze fests. It did more than just make me feel comfortable - humor helped me focus better on what was being said and remember important details during and well after the session had ended.

I also learned a thing or two about comfortable silences when I participated in a contextual session with two researchers. One researcher kept prodding and repeatedly asking questions while the other exuded a quiet and calm demeanor and simply patiently waited for me to complete my task and talk about it in my own time (and way). It won’t work in all situations or with all participants, but it made me feel relaxed and comfortable enough to talk through what I was thinking and seeing. This approach also made thinking aloud easier for me.

It’s important to remember that it doesn’t matter if you’re an experienced UX researcher or if you’re just starting out, everyone can learn something new from another researcher and stepping up into a session as an actual participant is a great way to do that.

3. Give back and grow our industry 🌱

One of my favourite things about the UX industry has always been its sense of community. We’re a group of people who care. We care about our users, we care about each other and we care about our capability as an industry and where we’re headed. Agreeing to be a participant in another researcher’s study is a great way to give back.

As I mentioned earlier, we use products and services too and in addition to this, there’s a whole heap of them out there designed just for us! It makes sense that in the same way that we as researchers ask our own customers and users to help us design better products, we should be open to doing the same for the people who design for us.

The cool thing about being a participant who is also a researcher is that we pick up issues other people might not. We might be a little tougher and less likely to let a usability issue slide. We might be the person that provides the external and fresh-eyed validation a researcher needs to convince a stakeholder that a design needs to be changed or worked on some more. A researcher in the participant’s chair is a powerful hybrid - it’s a participant and expert reviewer in one.

As a general rule of thumb, if you’re invited to participate in another researcher’s study, I do think it’s best to always be upfront with them about who you are and what you do so that they can determine if you are potentially too biased to be included. It’s their study and informed consent matters. Think about what you would want as a researcher. And if they’re specifically asking you to participate because you’re a researcher - that’s awesome!

So those are just some of the reasons why you should take a spin in the participant’s chair. Professional development is a lifelong learning process for us all. I’m looking forward to implementing what I’ve learned from these experiences and continuing to plonk myself in that participant chair to keep growing my perspective and helping out other researchers along the way.

Happy researching (and participating)!

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Web usability guide

There’s no doubt usability is a key element of all great user experiences, how do we apply and test usability principles for a website? This article looks at usability principles in web design, how to test it, practical tips for success and a look at our remote testing tool, Treejack.

A definition of usability for websites 🧐📖

Web usability is defined as the extent to which a website can be used to achieve a specific task or goal by a user. It refers to the quality of the user experience and can be broken down into five key usability principles:

  • Ease of use: How easy is the website to use? How easily are users able to complete their goals and tasks? How much effort is required from the user?
  • Learnability: How easily are users able to complete their goals and tasks the first time they use the website?
  • Efficiency: How quickly can users perform tasks while using your website?
  • User satisfaction: How satisfied are users with the experience the website provides? Is the experience a pleasant one?
  • Impact of errors: Are users making errors when using the website and if so, how serious are the consequences of those errors? Is the design forgiving enough make it easy for errors to be corrected?

Why is web usability important? 👀

Aside from the obvious desire to improve the experience for the people who use our websites, web usability is crucial to your website’s survival. If your website is difficult to use, people will simply go somewhere else. In the cases where users do not have the option to go somewhere else, for example government services, poor web usability can lead to serious issues. How do we know if our website is well-designed? We test it with users.

Testing usability: What are the common methods? 🖊️📖✏️📚

There are many ways to evaluate web usability and here are the common methods:

  • Moderated usability testing: Moderated usability testing refers to testing that is conducted in-person with a participant. You might do this in a specialised usability testing lab or perhaps in the user’s contextual environment such as their home or place of business. This method allows you to test just about anything from a low fidelity paper prototype all the way up to an interactive high fidelity prototype that closely resembles the end product.
  • Moderated remote usability testing: Moderated remote usability testing is very similar to the previous method but with one key difference- the facilitator and the participant/s are not in the same location. The session is still a moderated two-way conversation just over skype or via a webinar platform instead of in person. This method is particularly useful if you are short on time or unable to travel to where your users are located, e.g. overseas.
  • Unmoderated remote usability testing: As the name suggests, unmoderated remote usability testing is conducted without a facilitator present. This is usually done online and provides the flexibility for your participants to complete the activity at a time that suits them. There are several remote testing tools available ( including our suite of tools ) and once a study is launched these tools take care of themselves collating the results for you and surfacing key findings using powerful visual aids.
  • Guerilla testing: Guerilla testing is a powerful, quick and low cost way of obtaining user feedback on the usability of your website. Usually conducted in public spaces with large amounts of foot traffic, guerilla testing gets its name from its ‘in the wild’ nature. It is a scaled back usability testing method that usually only involves a few minutes for each test but allows you to reach large amounts of people and has very few costs associated with it.
  • Heuristic evaluation: A heuristic evaluation is conducted by usability experts to assess a website against recognized usability standards and rules of thumb (heuristics). This method evaluates usability without involving the user and works best when done in conjunction with other usability testing methods eg Moderated usability testing to ensure the voice of the user is heard during the design process.
  • Tree testing: Also known as a reverse card sort, tree testing is used to evaluate the findability of information on a website. This method allows you to work backwards through your information architecture and test that thinking against real world scenarios with users.
  • First click testing: Research has found that 87% of users who start out on the right path from the very first click will be able to successfully complete their task while less than half ( 46%) who start down the wrong path will succeed. First click testing is used to evaluate how well a website is supporting users and also provides insights into design elements that are being noticed and those that are being ignored.
  • Hallway testing: Hallway testing is a usability testing method used to gain insights from anyone nearby who is unfamiliar with your project. These might be your friends, family or the people who work in another department down the hall from you. Similar to guerilla testing but less ‘wild’. This method works best at picking up issues early in the design process before moving on to testing a more refined product with your intended audience.

Online usability testing tool: Tree testing 🌲🌳🌿

Tree testing is a remote usability testing tool that uses tree testing to help you discover exactly where your users are getting lost in the structure of your website. Treejack uses a simplified text-based version of your website structure removing distractions such as navigation and visual design allowing you to test the design from its most basic level.

Like any other tree test, it uses task based scenarios and includes the opportunity to ask participants pre and post study questions that can be used to gain further insights. Tree testing is a useful tool for testing those five key usability principles mentioned earlier with powerful inbuilt features that do most of the heavy lifting for you. Tree testing records and presents the following for each task:

  • complete details of the pathways followed by each participant
  • the time taken to complete each task
  • first click data
  • the directness of each result
  • visibility on when and where participants skipped a task

Participant paths data in our tree testing tool 🛣️

The level of detail recorded on the pathways followed by your participants makes it easy for you to determine the ease of use, learnability, efficiency and impact of errors of your website. The time taken to complete each task and the directness of each result also provide insights in relation to those four principles and user satisfaction can be measured through the results to your pre and post survey questions.

The first click data brings in the added benefits of first click testing and knowing when and where your participants gave up and moved on can help you identify any issues.Another thing tree testing does well is the way it brings all data for each task together into one comprehensive overview that tells you everything you need to know at a glance. Tree testing's task overview- all the key information in one placeIn addition to this, tree testing also generates comprehensive pathway maps called pietrees.

Each junction in the pathway is a piechart showing a statistical breakdown of participant activity at that point in the site structure including details about: how many were on the right track, how many were following the incorrect path and how many turned around and went back. These beautiful diagrams tell the story of your usability testing and are useful for communicating the results to your stakeholders.

Usability testing tips 🪄

Here are seven practical usability testing tips to get you started:

  • Test early and often: Usability testing isn’t something that only happens at the end of the project. Start your testing as soon as possible and iterate your design based on findings. There are so many different ways to test an idea with users and you have the flexibility to scale it back to suit your needs.
  • Try testing with paper prototypes: Just like there are many usability testing methods, there are also several ways to present your designs to your participant during testing. Fully functioning high fidelity prototypes are amazing but they’re not always feasible (especially if you followed the previous tip of test early and often). Paper prototypes work well for usability testing because your participant can draw on them and their own ideas- they’re also more likely to feel comfortable providing feedback on work that is less resolved! You could also use paper prototypes to form the basis for collaborative design sessions with your users by showing them your idea and asking them to redesign or design the next page/screen.
  • Run a benchmarking round of testing: Test the current state of the design to understand how your users feel about it. This is especially useful if you are planning to redesign an existing product or service and will save you time in the problem identification stages.
  • Bring stakeholders and clients into the testing process: Hearing how a product or service is performing direct from a user can be quite a powerful experience for a stakeholder or client. If you are running your usability testing in a lab with an observation room, invite them to attend as observers and also include them in your post session debriefs. They’ll gain feedback straight from the source and you’ll gain an extra pair of eyes and ears in the observation room. If you’re not using a lab or doing a different type of testing, try to find ways to include them as observers in some way. Also, don’t forget to remind them that as observers they will need to stay silent for the entire session beyond introducing themselves so as not to influence the participant - unless you’ve allocated time for questions.
  • Make the most of available resources: Given all the usability testing options out there, there’s really no excuse for not testing a design with users. Whether it’s time, money, human resources or all of the above making it difficult for you, there’s always something you can do. Think creatively about ways to engage users in the process and consider combining elements of different methods or scaling down to something like hallway testing or guerilla testing. It is far better to have a less than perfect testing method than to not test at all.
  • Never analyse your findings alone: Always analyse your usability testing results as a team or with at least one other person. Making sense of the results can be quite a big task and it is easy to miss or forget key insights. Bring the team together and affinity diagram your observations and notes after each usability testing session to ensure everything is captured. You could also use Reframer to record your observations live during each session because it does most of the analysis work for you by surfacing common themes and patterns as they emerge. Your whole team can use it too saving you time.
  • Engage your stakeholders by presenting your findings in creative ways: No one reads thirty page reports anymore. Help your stakeholders and clients feel engaged and included in the process by delivering the usability testing results in an easily digestible format that has a lasting impact. You might create an A4 size one page summary, or maybe an A0 size wall poster to tell everyone in the office the story of your usability testing or you could create a short video with snippets taken from your usability testing sessions (with participant permission of course) to communicate your findings. Remember you’re also providing an experience for your clients and stakeholders so make sure your results are as usable as what you just tested.

Related reading 🎧💌📖

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1 min read

5 ways to measure UX return on investment

Return on investment (ROI) is often the term on everyone’s lips when starting a big project or even when reviewing a website. It’s especially popular with those that hold the purse strings.  As UX researchers it is important to consider the ROI of the work we do and understand how to measure this. 

We’ve lined up 5 key ways to measure ROI for UX research to help you get the conversation underway with stakeholders so you can show real and tangible benefits to your organization. 

1. Meet and exceed user expectations

Put simply, a product that meets and exceeds user expectations leads to increased revenue. When potential buyers are able to find and purchase what they’re looking for, easily, they’ll complete their purchase, and are far more likely to come back. The simple fact that users can finish their task will increase sales and improve overall customer satisfaction which has an influence on their loyalty. Repeat business means repeat sales. Means increased revenue.

Creating, developing and maintaining a usable website is more important than you might think. And this is measurable! Tracking and analyzing website performance prior to the UX research and after can be insightful and directly influenced by changes made based on UX research.

Measurable: review the website (product) performance prior to UX research and after changes have been made. The increase in clicks, completed tasks and/or baskets will tell the story.

2. Reduce development time

UX research done at the initial stages of a project can lead to a reduction in development time of by 33% to 50%! And reduced time developing, means reduced costs (people and overheads) and a speedier to market date. What’s not to love? 

Measurable: This one is a little more tricky as you have saved time (and cost) up front. Aiding in speed to market and performance prior to execution. Internal stakeholder research may be of value post the live date to understand how the project went.

3. Ongoing development costs

And the double hitter? Creating a product that has the user in mind up front, reduces the need to rehash or revisit as quickly. Reducing ongoing costs. Early UX research can help with the detection of errors early on in the development process. Fixing errors after development costs a company up to 100 times more than dealing with the same error before development.

Measureable: Again, as UX research has saved time and money up front this one can be difficult to track. Though depending on your organization and previous projects you could conduct internal research to understand how the project compares and the time and cost savings.

4. Meeting user requirements

Did you know that 70% of projects fail due to the lack of user acceptance? This is often because project managers fail to understand the user requirements properly. Thanks to UX research early on, gaining insights into users and only spending time developing the functions users actually want, saving time and reducing development costs. Make sure you get confirmation on those requirements by iterative testing. As always, fail early, fail often. Robust testing up front means that in the end, you’ll have a product that will meet the needs of the user.

Measurable: Where is the product currently? How does it perform? Set a benchmark up front and review post UX research. The deliverables should make the ROI obvious.

5. Investing in UX research leads to an essential competitive advantage.

Thanks to UX research you can find out exactly what your customers want, need and expect from you. This gives you a competitive advantage over other companies in your market. But you should be aware that more and more companies are investing in UX while customers are ever more demanding, their expectations continue to grow and they don’t tolerate bad experiences. And going elsewhere is an easy decision to make.

Measurable: Murky this one, but no less important. Knowing, understanding and responding to competitors can help keep you in the lead, and developing products that meet and exceed those user expectations.

Wrap up

Showing the ROI on the work we do is an essential part of getting key stakeholders on board with our research. It can be challenging to talk the same language, ultimately we all want the same outcome…a product that works well for our users, and delivers additional revenue.

For some continued reading (or watching in this case), Anna Bek, Product and Delivery Manager at Xplor explored the same concept of "How to measure experience" during her UX New Zealand 2020 – watch it here as she shares a perspective on UX ROI.

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