In his Alertbox article entitled When to Use Which User Experience Research Methods, Christian Rohrer gives a good overview of various research methods and when to apply them.

The field of user experience, is blessed (or cursed) with a very wide range of research methods, ranging from tried-and-true methods such as lab-based usability studies to those that have been more recently developed, such as desirability studies (to measure aesthetic appeal).

You can't use the full set of methods on every project, but most design teams benefit from combining insights from multiple research methods. The key question is what to do when. To better understand when to use which method, it is helpful to realize that they differ along 3 dimensions:

  • Attitudinal vs. Behavioral
  • Qualitative vs. Quantitative
  • Context of Website or Product Use

The plotting of research methods according to these three dimensions is quite handy, as is his advice regarding combining multiple methods for any particular project.

Of particular interest is the "Context of Product Use" dimension. This dimension refers to whether or not you're asking the participant to use the product in a certain way, as opposed to just observing how they might naturally use it. This can have a big impact on the method you would employ, and highly scripted approaches risk Asking Participants to “Pretend” in User Studies (which Jared Spool recently wrote about).

While this article should be quite useful in helping people to narrow down the most appropriate design research methods to use, it might not be enough. Inexperienced readers may still not be able to decide which method to use, even assessing all possible methods using these dimensions. What's missing is the X factor regarding which factors are best for certain situations, but this probably comes down purely to experience and is a professional preference that develops over time (and would thus be difficult to capture in an article). All in all, a very useful article.

[Chris, if it's not on the blog, it's just not on :)]