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Participant Recruitment

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1 min read

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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1 min read

13 time-saving tips and tools for conducting great user interviews

User interviews are a great research method you can use to gain qualitative data about your users, and understand what they think and feel. But they can be quite time consuming, which can sometimes put people off doing them altogether.They can be a bit of a logistical nightmare to organize. You need to recruit participants, nail down a time and place, bring your gear, and come up with a Plan B if people don’t show up. All of this can take up a fair bit of back and forthing between your research team and other people, and it’s a real headache when you have a deadline to work to.So, how can you reap the great rewards and insights that user interviews provide, while spending less time planning and organizing them? Here are 15 tips and tools to help get you started.

Preparation

1) Come up with a checklist

Checklists can be lifesavers, especially when your brain is running 100 miles an hour and you’re wondering if you’ve forgotten to even introduce yourself to your participant.Whether you’re doing your research remotely or in person, it always helps to have a list of all the tasks you need to do so you can check them off one by one.A great checklist should include:

  • the items you need to bring to your sessions (notebooks, laptop, pens, water, and do NOT forget your laptop charger!)
  • any links you need to send to your interviewee if speaking to them remotely (Google Hangouts, webex etc.)
  • a reminder to get consent to record your interview session
  • a reminder to hit the record button

Scripts are also useful for cutting down time. Instead of “umm-ing” and “ahh-ing” your way through your interview, you can have a general idea of what you’ll talk about. Scripts will likely change between each project, but having a loose template that you can chop and change pretty easily will help you save time in the future.Some basic things you’ll want to include in your script:

  • an introduction of yourself, and some ice-breaker questions to build a rapport with your participant
  • your research goals and objectives — what/who you’re doing this research for and why
  • how your research will be used
  • the questions you’re going to ask
  • tying up loose ends — answering questions from your participant and thanking them very much for their time.

2) Build up a network of participants to choose from

This is another tip that requires a bit of legwork at the start, but saves lots of hassle later on. If you build up a great network of people willing to take part in your research, recruiting can become much easier.Perhaps you can set up a research panel that people can opt into through your website (something we’ve done here at Optimal Workshop that has been a huge help). If you’re working internally and need to interview users at your own company, you can do a similar thing. Reach out to managers or team leaders to get employees on board, get creative with incentives, reward people with thanks or cakes in public — there are loads of ideas.

3) Do your interviews remotely

Remote user research is great. It allows you to talk to all types of people anywhere in the world, without having to spend time and money for travel to get to them.There are many different tools you can use to conduct your user interview remotely.Some easy to use and free ones are Google Hangouts and Skype. As a bonus, it’s likely your participants will already have one of these installed, saving them time and hassle — just don’t forget to record your session.Here are a couple of recording tools you can use:

  • QuickTime
  • iShowU HD
  • Pamela for Skype

4) Rehearse, rehearse, rehearse

Make sure you’re not wasting any precious research time and rehearse your interview with a colleague or friend. This will help you figure out anything you’ve missed, or what could potentially go wrong that could cause you time delays and headaches on the day.

  • Do your questions make sense, and are they the right kinds of questions?
  • Test your responses — are you making sure you stay neutral so you don’t lead your participants along?
  • Does your script flow naturally? Or does it sound too scripty?
  • Are there any areas that technology could become a hindrance, and how can you make sure you avoid this?

5) Use scheduling tools to book sessions for you

Setting up meetings with colleagues can be difficult, but when you’re reaching out to participants who are volunteering their precious time it can be a nightmare.Make it easier for all involved and use an easy scheduling tool to get rid of most of the hard work.Simply enter in a few times that you’re free to host sessions, and your participants can select which ones work for them.Here are a couple of tools to get you started:

  • Calendly
  • NeedtoMeet
  • Boomerang Calendar
  • ScheduleOnce

Don’t forget to automate the reminder emails to save yourself some time. Some of the above tools can sort that out for you!

In-session

6) Avoid talking about yourself — stick to your script!

When you’re trying to build a rapport with your participant, it’s easy to go overboard, get off track and waste precious research time. Avoid talking about yourself too much, and focus on asking about your participant, how they feel, and what they think. Make sure you keep your script handy so you know if you’re heading in the wrong direction.

7) Record interviews, transcribe later

In many user interview scenarios, you’ll have a notetaker to jot down key observations as your session goes on. But if you don’t have the luxury of a notetaker, you’ll likely be relying on yourself to take notes. This can be really distracting when you’re interviewing someone, and will also take up precious research time. Instead, record your interview and only note down timestamps when you come across a key observation.

8) Don’t interrupt

Ever had something to say and started to explain it to someone, only to get interrupted then lose your train of thought? This can happen to your participants if you’re not careful, which can mean delays with getting the information you need. Stay quiet, and give your participant a few seconds before asking what they’re thinking.

9) Don’t get interrupted

If you’re hosting your interview at your office, let your coworkers know so they don’t interrupt you. Hang a sign up on the door of your meeting room and make sure you close the door. If you’re going out of your office, pick a location that’s quiet and secluded like a meeting room at a library, or a quiet corner in a cafe.

10) Take photos of the environment

If you’re interviewing users in their own environment, there are many little details that can help you with your research. But you could spend ages taking note of all these details in your session. You can get a good idea of what your participant’s day is like by snapping some images of their workstations, tech they use, and the office as a whole. Use your phone and pop these into Evernote or Dropbox to analyze later.

Analysis

11) Use Reframer to analyze your data

Qualitative research produces very powerful data, but it also produces a lot of it. It can take you and your team hours, even days, to go through it all.Use a qualitative research tool such as Reframer to tag your observations so you can easily build themes and find patterns in your data while saving hours of analysis. Tags might be related to a particular subject you’re discussing with a participant, a really valuable quote, or even certain problems your participants have encountered — it all depends on your project.

12) Make collaboration simple

Instead of spending hours writing up some of your findings on Post-it notes and sticking them up on a wall to discuss with your teammates, you can quickly and easily do this online with Trello or MURAL. This is definitely a big timesaver if you’ve got some team members who work remotely.

13) Make your findings easy to read

Presenting your findings to stakeholders can be difficult, and extremely time consuming if you need to explain it all in easy-to-understand terms. Save time and make it easier for your stakeholders by compiling your findings into an infographic, engaging data visualization, or slideshow presentation. Just make sure you bring all the stats you need to answer any questions from stakeholders.For more actionable tips and tricks from UX professionals all over the world, check out our latest ebook. Download and print out templates and checklists, and become a pro for your next user interview.Get our new ebook

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