"One's ability to retrieve (or recognize) an item is heavily influenced by the relation between that item's storage and retrieval contexts – is indisputable." 1
When it comes to choosing ways to conduct user research, it's very easy to put users into a conference room to get what you need quickly. Business types love this approach. But typically, we try to go a step or two beyond the conference room approach, based in part, on the unreliable nature of memory. It's too easy to forget the minutia.
Interestingly, from a UX perspective we all generally accept that this is true. And as an alternative (or complimentary) approach – we agree that contextual inquiry yields more rich, accurate information to inform the design process.
I've heard many great reasons – including "You get a better understanding of the environment." To which I totally agree. And there are any more good reasons.
I want to add one more good reason to the list.
Because we know that context can effect memory recall – doesn't it make sense that users will be more accurate and remember more detail about their work, when they are sitting at their desk? Memory just works better when you are trying to recall information from the same context that it was encoded.
There may be some research out there on this – specifically in the context of HCI research – but I wanted to share the thought. It seems like another good way to justify the time (and possible expense) of taking the time for thorough user research.
Here's a paper you can read if you're interested. I found it through Google Scholar and the ISU library.
1. Environmental Context and Human Memory
STEVEN M. SMITH and ARTHUR GLENBERG
University of Wisconsin, Madison, Wisconsin 5370