How do you know which UX research method to do when?
Let's look at a few criteria to help us decide.
First, think about watching or asking.
Research can be either behavioral and observed by researchers or self-reported by the user,
which is also known as attitudinal.
When your research question has to do with what people actually do, or whether something
is discoverable, findable, understandable, or usable, it's most informative to observe this.
So use a method like a usability test.
If you're in very early design phases, like you have sketches or wireframes, you can still
observe usage by giving people tasks to do, with just those paper sketches.
As your design progresses, create high-fidelity, dynamic, clickable prototypes to test.
When you have design concepts, it's tempting to just show it to users and ask what they think.
But instead, direct the user to try and actually do something.
If you're wondering what people have to say, like whether they believe they'll like or
dislike something, that can be researched with self-reported methods like
interviews, surveys, and focus groups.
Another criteria to help us decide which research method to use when relates to numbers or stories.
Or quantitative or qualitative research.
If your goal is to compare products or designs, to get benchmarks to which the future design
will be compared, or to compute expected cost savings from design changes, you will use
a quantitative research method.
Some quantitative methods to use when you have these goals are card sorting, which calls
for about 20 users, tree testing, which calls for between 50 and 100 people, eyetracking
heatmaps, which need 40 users, quantitative usability tests, during which we watch people
do tasks and take measurements, like time on tasks and success rate,
we start with about 20 users for these and the number increases depending on the desired confidence interval
and statistical significance; web analytics, like A/B testing or multivariate testing,
which require many more users; surveys always require many more respondents.
On the other side is qualitative testing that we use to quickly and cheaply learn so we
can iterate the design and improve it as much as possible before releasing it.
Very early prototypes can be usability tested with just 2 target users.
Make a change based on what we observe, and then test it again with two more people.
The next criteria is tangible or not.
We also study people when we have no design at all.
Especially in very early design phases, we want to learn how people work and live.
A field study is a great method to use for these needs, when we go to users and observe
their every day activities.
Then if we care about user behavior, or ease of use for that matter, over time, then we
want to do a longer study, or a longitudinal study.
This might be a diary study in which people keep a journal or answer a series of questions;
another option is to do a series of surveys; and yet another appropriate research method
is a video journal or camera study, where people record themselves at certain times.
The last criteria I'll discuss for choosing UX research methods is context.
If you desire situational data that comes at the user's location, there are several options.
One is a field study where you go to the user's office, home, car, or other site.
Then you can still get some context information with the following methods, like a remote usability test.
Even a live, online intercept study gives a small amount of context and that catches
the user while he or she is actually attempting a task on your website.
And another type of study that goes by the same name, researchers intercept a person live
at a place like a coffee shop or mall.
These studies are usually very short and are okay to do in a chaotic setting.
The flip side of that are lab studies, where you opt for a controlled environment so you
can make the absolute most of the precious time that you have with your user.