Some like to call it an exploratory study. Some like to call it a formative study, but which ever you decide to go with, there are some things that you need to know.
What is Formative Research?
Formative research is that which is carried out with the intent of capturing qualitative or quantitative data that can help mold or form a product, service or design. As such, it's usually research that is done when a product, service or design is being first created, or as part of a redesign effort. (our definitions).
When should it occur?
As described in the definition offered above, this type of research is usually conducted pretty early in planning a design, or in evaluating for redesign.
What's the point?
The main purpose for formative research is to examine the usability of early design. If usability is defined as a measure of how well a design meets the users needs or expectations, without causing hindrance, hesitation or question, then the goal of this level of research is truly to make sure the design is taking it's first steps in the correct direction.
There's probably more, but this should get you on your way. I'd love to read your comments.