Embracing the Un-Science of Qualitative Research Part One – Small Sample Sizes are Super

If you’re into qualitative research at all, it wouldn’t have taken long before you had someone ask you about the statistical significance of your research and how you could back your findings with such a small sample size, or to find others out there trying to make qualitative research look more scientific by trying to extract hard data from it.

There are three main ways that you can try to make qualitative research look more scientific, being:

  1. Use a relatively large sample size
  2. Ensure that your test environment doesn’t change
  3. Ensure that your test approach doesn’t change (don’t change the script, and stick to it)

Now, there are some times when one or more of these tactics is appropriate, but conversely, in many instances it has been my experience that by breaking these rules, you are able to get much greater insight into the research question(s) you have set yourself.

There are many different kinds of qualitative research study, so in the interests of clarity, let’s pick one just like I’ve been working on this week – a lab based combination of interview & a wee bit of usability which is intended to ensure that my client’s proposition is sound, that it is being well communicated, that the users understand what the service is and how it works, and to weed out any critical usability issues.

In the interest of not making you read an enormous post, I’ve divided this into three parts. So, let’s start with part one – a large sample size. Now… to the best of my knowledge there is no scientific way to determine the correct number of participants in a qualitative research study. Now, I’m no statistician (if you are, please feel free to weigh in here), but it is my understanding that the likelihood of reaching a statistically significant result using the methodology I’ve described above, is pretty much nil. Not that it’s impossible, but you’d have to do a heck of a lot of interviewing.

And here’s one golden rule of qualitative research that always holds true – if the research is going to take too long or be too expensive, it will not happen. You can count on that one.

As a result, sample size for qualitative research is often driven by the time and budget available – and that’s not necessarily a bad thing. In fact, this is one subject upon which Jakob Nielson and I actually quite agree. Jakob says that most of the time elaborate usability testing is a waste of time and that you should test with no more than five users. He has a natty little graph that illustrates why this is so:

Problem Finding Curve

As you can see – by the time you’re up to five or six users, you’ve gotten to the bottom of most of the usability issues, and from then on you spend more time repeatedly seeing what you’ve already seen before and uncovering very few new findings. In my experience – this is as true for other aspects of research as it is for usability.

I would add a caveat which is that if you have user groups that are quite divergent in their attitudes, experience, or requirements/goals etc. you will want to ensure that you apply this rule to each of those groups. So, for example, if you have an audience of ‘buyers’ and an audience of ‘sellers’ you’ll want to get no more than five each from each key audience. One final caveat – when I say no more than five, I also say no fewer than three (and, what do you know, so does Jakob). You need at least three to identify what are actually patterns from those things that are just personal quirks – because that’s what you’re looking for here – the patterns.

Is it scientific to use such a small user group? If you want to make it look that way, you can look to Jakob for some algorithms and graphs. In my experience – it doesn’t matter whether it is scientific or not. The richness of the information and insight you receive even from this small sample size makes the return on investment enormous – and the small sample size makes it an activity that almost any project can incorporate into their timeline and budget. At the end of the day – those things are far more important than scientific validity.

Is it worth doing qualitative testing with only a small sample size? Absolutely yes. In fact, in many ways, this is the best way to do this research. Qualitative research is not about numbers, it is about the richness of the information and insight you can get access to by spending time with the people who form your audience (or potential audience), and looking for patterns in their reactions and responses.

In many cases, increasing the size of your sample so that it seems more ‘valid’ is a waste of time and money as the later interviews become more and more a repetition of finding you’ve already identified and confirmed. This time and money could be much better spent improving your product and conducting another round of research.

If it’s numbers you’re after – go do a survey. I say embrace and defend the small sample size of qualitative research.

What say you?

(Coming soon: Part Two – Ever-Evolving Prototypes are Ace)

What’s in it for me? Why people participate in social networking websites

Now that we’re all super excited about social media, and every man and his dog wants to do *something* to do with social networking, it seems a pertinent time to ask… but why?

Why does the world need your product or service to include ‘something social’? Why on earth would you want to create a *new* social networking service? Why does the world need another place to go and try to find all of their friends online and to… well… share stuff?

Good question – and one that doesn’t seem to be asked quite often enough, as we all rush towards being ‘socially compliant’ with our blogs and our wikis and our user generated content and our buddy/friends lists.

If you’re thinking of joining the bun rush (or your client has insisted that they must), I think the first and most important question to ask is from your potential users perspective – what’s in it for them? What’s their motivation to sign up, to find and make friends, to participate, and to come back, ever?

What’s the motivation of your employees (in an enterprise environment) to start or contribute to a blog or to add or edit content on a wiki?

The best framework that I’ve found so far for thinking about it has come via Tom Coates in his presentation ‘Greater Than The Sum of Its Parts‘ where he talks about personal motivation for users in social network environments

Tom quotes Peter Pollack’s ‘Economies of Online Cooperation’ and says that there are four key sources of personal motivation in online social networking, being:

  1. Anticipated Reciprocity
  2. Reputation
  3. ‘Sense of Efficacy’
  4. Identification with a group

Makes a lot of sense, doesn’t it. People participate in these things because they think they’ll get back what they put in (and perhaps more), it will enhance their reputation (making them more likely to be the go to person for the cool projects because they’ve established themselves as an expert in that area, for example), they can get things done faster (like using Twitter as Tech Support), or – because that’s where their people hang.

Of course, I’d add into that the Ambient Intimacy effect which I think is more about being connected and less about identification.

At the end of the day though, we *know* that people participate in social networks firstly because they get some value from it personally. The network effect that comes from that is a very welcome byproduct, but it will only come about if the prerequisite of personal value is met.

So, as you, or your client, are considering your foray into the world of social networking – please start by thinking carefully about what value you’re delivering to your user. What is their motivation for using your site? What’s in it for them.

If you can honestly and realistically overcome this first hurdle, then you might have a chance of creating something truly valuable and successful.

Run, don’t walk! (Conference plugs and discounts)

Two things you need to know today.

dConstruct (Brighton, UK) tickets go on sale tomorrow (10 July). They sell out fast. You don’t want to miss out – especially this year with such a great line up on the theme of designing the user experience.

UX Week (Washington DC) also looks amazing. Tickets are on sale for a little longer yet, but if you want to get in at a discounted rate, your chances run out this week. And, for something extra special, if you use the promo code ‘UXLR’ you’ll get a 15% discount on registration. Don’t say I don’t do anything for you. :)

I’ll be at both of these events and would love to see you there. Sing out if you’re coming along!