There is a school of thought within usability that asserts that during
facilitation, moderators should not speak to the participant as this interaction affects behaviour, and so invalidates the research.

It’s similar to the idea in ethnography that the very presence of an observer will lead to modifications and unnatural behaviour.

There is also the idea that people may not have conscious access to the real reason for their behaviour. In trying to explain their actions to the moderator they will introspect and provide an answer that they feel is rational, but is effectively made up.

Malcolm Gladwell sums this up something like this (I’m paraphrasing here): Basically—we feel about a thing, then act.

And then, the moderator asks us why.

Faced with this question, we try to think up a plausible, rational-sounding explanation for our actions. And then—here’s the thing—we alter our future behaviour to match that rationalised thinking.

Wilson and Schooler investigated this phenomenon in depth, concluding: “We come up with a plausible-sounding reason for why we might like or dislike something, and then we adjust our true preference to be in line with that plausible-sounding reason.”

So if we had never been asked why we did something, we might continue doing things differently.

However, without entering into conversation with a participant we can only say what happened; and with no insight as to ‘why’ we can’t make decisions and can’t improve.

The problem then is that we need to know ‘why’ but can’t ask ‘why’.

Here’s a few methods that we use at Flow:

Sometimes more open interviewing will tell you what you need. If you need to know why a participant clicked on that link (or didn’t), questions such as “Tell me about the kinds of things you have looked for in the past on a site like this?” can tell you about the keywords or visual elements that a participant is searching for.

“What are you interested in finding out at the moment on a site like this?” can tell you what it is they haven’t found yet.

Ann Light continues in this vein: “An undesirable, but common, way of interrupting evocation [the flow of recall, in this instance] is to invite the interviewee into a judgemental mode. To avoid this, there is no use of questions starting ‘Why... ?’ Instead, carefully manipulated ‘How... ?’ and ‘What... ?’ questions cover the same ground: ‘How did you know that X?’ ‘What were you thinking at the moment when X?’ This does not interrupt the recounting process. So ‘tell me how it was that you came to be looking for this site that day’ does the work of ‘why were you looking... ?’”

Of course together with the different ways of asking why, the facilitator needs also to combine high degrees of empathy and observation. Interpreting what the participant does and says, and ultimately understanding those things will enable us to make better decisions about what to do next.

References

Wilson and Schooler (1991) Thinking too much: introspection can reduce the quality of preferences and decisions, Journal of Personality and Social Psychology 60 (2), pp181-192
Light, A (2006) Adding Method to Meaning: a technique for exploring
peoples’ experience with digital products, Behaviour & Information Technology 25 (2), pp175-187