How many participants do I need for qualitative research?

Usability testing is one of the best ways to measure how easy and intuitive to use something is by testing it with real people. You can read about the basics of usability testing here.

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Earlier this year, a small team within Optimal Workshop completely redesigned the company blog. More than anything, we wanted to create something that was user-friendly for our readers and would give them a reason to return. I was part of that team, and we ran numerous sessions interviewing regular readers as well as people unfamiliar with our blog. We also ran card sorts, tree tests and other studies to find out all we could about how people search for UX content. Unsurprisingly, one of the most valuable activities we did was usability testing – sitting down with representative users and watching them as they worked through a series of tasks we provided. We asked general questions like “Where would you go to find information about card sorting”, and we also observed them as they searched through our website for learning content.

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By stripping away any barriers between ourselves and our users and observing them as they navigated through our website and learning resources, as well as those of other companies, we were able to build a blog with these people’s behaviors and motivations in mind.

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Usability testing is an invaluable research method, and every user researcher should be able to run sessions effectively. Here are 5 tips for doing so, in no particular order.

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1. Clarify your goals with stakeholders

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Never go into a usability test blind. Before you ever sit down with a participant, make sure you know exactly what you want to get out of the session by writing down your research goals. This will help to keep you focused, essentially giving you a guiding light that you can refer back as you go about the various logistical tasks of your research. But you also need to take this a step further. It’s important to make sure that the people who will utilize the results of your research – your stakeholders – have an opportunity to give you their input on the goals as early as possible.

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If you’re running usability tests with the aim of creating marketing personas, for example, meet with your organization’s marketing team and figure out the types of information they need to create these personas. In some cases, it’s also helpful to clarify how you plan to gather this data, which can involve explaining some of the techniques you’re going to use.

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Lastly, find out how your stakeholders plan to use your findings. If there are a lot of objectives, organize your usability test so you ask the most important questions first. That way, if you end up going off track or you run out of time you’ll have already gathered the most important data for your stakeholders.

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2. Be flexible with your questions

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A list of pre-prepared questions will help significantly when it comes time to sit down and run your usability testing sessions. But while a list is essential, sometimes it can also pay to ‘follow your nose’ and steer the conversation in a (potentially) more fruitful direction.

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How many times have you been having a conversation with a friend over a drink or dinner, only for you both to completely lose track of time and find yourselves discussing something completely unrelated? While it’s not good practice to let your usability testing sessions get off track to this extent, you can surface some very interesting insights by paying close attention to a user’s behavior and answers during a testing session and following interesting leads.

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Ideally, and with enough practice, you’ll be able to answer your core (prepared) questions and ask a number of other questions that spring to mind during the session. This is a skill that takes time to master, however.

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3. Write a script for your sessions

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While a usability test script may sound like a fancy name for your research questions, it’s actually a document that’s much more comprehensive. If you prepare it correctly (we’ll explain how below), you’ll have a document that you can use to capture in-depth insights from your participants.

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Here are some of the key things to keep in mind when putting together your script:

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• Write a friendly introduction – It may sound obvious, but taking the time to come up with a friendly, warm introduction will get your sessions off to a much better start. The bonus of writing it down is that you’re far less likely to forget it!
• Ask to record the session – It’s important to record your session (whether through video or audio), as you’ll want to go back later and analyze any details you may have missed. This means asking for explicit permission to record participants. In addition to making them feel more comfortable, it’s just good practice to do so.
• Allocate time for the basics – Don’t dive into the complex questions first, use the first few minutes to gather basic data. This could be things like where they work and their familiarity with your organization and/or product.
• Encourage them to explain their thought process – “I’d like you to explain what you’re doing as you make your way through the task”. This simple request will give you an opportunity to ask follow-up questions that you otherwise may not have thought to ask.
• Let participants know that they’re not being tested – Whenever a participant steps into the room for a test, they’re naturally going to feel like they’re being tested. Explain that you’re testing the product, not them. It’s also helpful to let them know that there are no right or wrong answers. This is an important step if you want to keep them relaxed.

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It’s often easiest to have a document with your script printed out and ready to go for each usability test.

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4. Take advantage of software

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You’d never see a builder without a toolbox full of a useful assortment of tools. Likewise, software can make the life of a user research that much easier. The paper-based ways of recording information are still perfectly valid, but introducing custom tools can make both the logistics of user research and the actual sessions themselves much easier to manage.

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Take a tool like Calendly, for example. This is a powerful piece of scheduling software that almost completely takes over the endless back and forth of scheduling usability tests. Calendly acts as a middle man between you and your participants, allowing you to set the times you’re free to host usability tests, and then allowing participants to choose a session that suits them from these times.

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Our very own Reframer makes the task of running usability tests and analyzing insights that much easier. During your sessions, you can use Reframer to take comprehensive notes and apply tags like “positive” or “struggled” to different observations. Then, after you’ve concluded your tests, Reframer’s analysis function will help you understand wider themes that are present across your participants.

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There’s another benefit to using a tool like Reframer. Keeping all of your notes in place will mean you easily pull up data from past research sessions whenever you need to.

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5. Involve others

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Usability tests (and user interviews, for that matter) are a great opportunity to open up research to your wider organization. Whether it’s stakeholders, other members of your immediate team or even members of entirely different departments, giving them the chance to sit down with users will show them how their products are really being used. If nothing else, these sessions will help those within your organization build empathy with the people they’re building products for.

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There are quite a few ways to bring others in, such as:

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• To help you set up the research – This can be a helpful exercise for both you (the researcher) and the people you’re bringing in. Collaborate on the overarching research objectives, ask them what types of results they’d like to see and what sort of tasks they think could be used to gather these results.
• As notetakers – Having a dedicated notetaker will make your life as a researcher significantly easier. This means you’ll have someone to record any interesting observations while you focus on running the session. Just let them know what types of notes you’d like to see.
• To help you analyze the data – Once you’ve wrapped up your usability testing sessions, bring others in to help analyze the findings. There’s a good chance that an outside perspective will catch something you may miss. Also, if you’re bringing stakeholders into the analysis stage, they'll get a clearer picture of what it means and where the data came from.

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There are myriad other tips and best practices to keep in mind when usability testing, many of which we cover in our introductory page. Important considerations include taking good quality notes, carefully managing participants during the session (not giving them too much guidance) and remaining neutral throughout when answering their questions. If you feel like we’ve missed any really important points, feel free to leave a comment!

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Read more

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• Usability testing 101 – About to run your first usability test? Check out our handy 101 guide. You’ll also learn how you can use our qualitative research tool Reframer most effectively.
• What is usability testing? – Learn about the concepts of usability testing and how you can develop a plan for your own testing sessions.
• How to run fast and affordable usability tests with hard-to-reach, high-earning users – Finding the right participants for your usability tests can seem pretty tricky. Here’s how you can get the right people for your particular project.

Qualitative user research is about exploration. Exploration is about the journey, not only the destination (or outcome). Gaining information and insights about your users through interviews, usability testing, contextual, observations and diary entries. Using these qualitative research methods to not only answer your direct queries, but to uncover and unravel your users ‘why’.

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It can be important to use qualitative research to really dig deep, get to know your users and get inside their heads, and their reasons. Creating intuitive and engaging products that deliver the best user experience. 

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What is qualitative research? 🔎

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The term ‘qualitative’ refers to things that cannot be measured numerically and qualitative user research is no exception. Qualitative research is primarily an exploratory research method that is typically done early in the design process and is useful for uncovering insights into people’s thoughts, opinions, and motivations. It allows us to gain a deeper understanding of problems and provides answers to questions we didn’t know we needed to ask. 

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Qualitative research could be considered the ‘why’. Where quantitative user research uncovers the how or the what users want. Qualitative user research will uncover why they make decisions (and possibly much more).

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Priorities ⚡⚡⚡⚡

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When undertaking user research it is great to do a mix of quantitative and qualitative research. Which will round out the numbers with human driven insights.

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Quantitative user research methods, such as card sorting or tree testing, will answer the ‘what’ your users want, and provide data to support this. These insights are number driven and are based on testing direct interaction with your product. This is super valuable to report to stakeholders. Hard data is difficult to argue what changes need to be made to how your information architecture (IA) is ordered, sorted or designed. To find out more about the quantitative research options, take a read.

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Qualitative user research, on the other hand, may uncover a deeper understanding of ‘why’ your users want the IA ordered, sorted or designed a certain way.  The devil is in the detail afterall and great user insights are discoverable. 

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Priorities for your qualitative research needs to be less about the numbers, and more on discovering your users ‘why’. Observing, listening, questioning and looking at reasons for users decisions will provide valuable insights for product design and ultimately improve user experience.

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Usability Testing - this research method is used to evaluate how easy and intuitive a product is to use.  Observing, noting and watching the participant complete tasks without interference or questions can uncover a lot of insights that data alone can’t give. This method can be done in a couple of ways, moderated or unmoderated. While it can be quicker to do unmoderated and easier to arrange, the deep insights will come out of moderated testing. 

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Observational - with this qualitative research method your insights will be uncovered from observing and noting what the participant is doing, paying particular attention to their non-verbal communication. Where do they demonstrate frustration, or turn away from the task, or change their approach? Factual note taking, meaning there shouldn’t be any opinions attached to what is being observed, is important to keep the insights unbiased.

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Contextual - paying attention to the context in which the interview or testing is done is important. Is it hot, loud, cold or is the screen of their laptop covered in post-its that make it difficult to see? Or do they struggle with navigating using the laptop tracker? All of this noted, in a factual manner, without personal inferring or added opinion based observations can give a window into why the participant struggled or was frustrated at any point.

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These research methods can be done as purely observational research (you don’t interview or converse with your participant) and noting how they interact (more interested in the process than the outcome of their product interaction). Or, these qualitative research methods can be coupled with an

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Interview - a series of questions asked around a particular task or product. Careful note taking around what the participant says as well as noting any observations. This method should allow a conversation to flow. Whilst the interviewer should be prepared with a list of questions around their topic, remain flexible enough to dig deeper where there might be details or insights of interest. An interviewer that is comfortable in getting to know their participants unpicks reservations and allows a flow of conversation, and generates amazing insights.

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With an interview it can be of use to have a second person in the room to act as the note taker. This can free up the interviewer to engage with the participant and unpick the insights.

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Using a great note taking side kick, like our Reframer, can take the pain out of recording all these juicy and deep insights. Time-stamping, audio or video recordings and notes all stored in one place. Easily accessed by the team, reviewed, reports generated and stored for later.

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Let’s consider 🤔

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You’re creating a new app to support your gym and it’s website. You’re looking to generate personal training bookings, allow members to book classes or have updates and personalise communication for your members. But before investing in final development it needs to be tested. How do your users interact with it? Why would they want to? Does it behave in a way that improves the user experience? Or does it simply not deliver? But why?

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First off, using quantitative research like Chalkmark would show how the interface is working. Where are users clicking, where do they go after that. Is it simple to use? You now have direct data that supports your questions, or possibly suggests a change of design to support quicker task completion, or further engagement.

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While all of this is great data for the design, does it dig deep enough to really get an understanding of why your users are frustrated? Do they find what they need quickly? Or get completely lost? Finding out these insights and improving on them can make the most of your users’ experience.

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When quantitative research is coupled with robust qualitative research that prioritizes an in-depth understanding of what your users need, ultimately the app can make the most of your users’ experience.

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Using moderated usability testing for your gym app, observations can be made about how the participant interacts with the interface. Where do they struggle, get lost, or where do they complete a task quickly and simply. This type of research enhances the quantitative data and gives insight into where and why the app is or isn't performing.

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Then interviewing participants about why they make decisions on the app, how they use it and why they would use it. These focussed questions, with some free flow conversation will round out your research. Giving valuable insights that can be reviewed, analyzed and reported to the product team and key stakeholders. Focussing the outcome, and designing a product that delivers on not just what users need, but in-depth understand of why. 

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Wrap Up 🥙

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Quantitative and qualitative user research do work hand in hand, each offering a side to the same coin. Hard number driven data with quantitative user research will deliver the what needs to be addressed. With focussed quantitative research it is possible to really get a handle on why your users interact with your product in a certain way, and how. 

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The Optimal Workshop platform has all the tools, research methods and even the note taking tools you need to get started with your user research, now, not next week! See you soon.

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!