A “straw man” in the most general sense is a sneaky kind of rhetorical argument based on misrepresenting an opponent’s argument . In the design world, on the other-hand, a “straw man” is an artefact of some kind — like a page design, flow chart, storyboard, etc. — intended to initiate discussion.
According to Donna Spencer in her article Using a “strawman” for page layout design,
The strawman is created with the intent that it will be pulled apart and discarded. It is used to encourage discussion of the layout’s strengths and weaknesses and to generate better designs.
In my experience, a straw man is useful for more than a design facilitator. I’ve used straw men designs to help the development team build momentum; it wasn’t an issue of generating a better design, but of
- getting past the hurdle of back-end software engineers coming up with a UI design
- providing another perspective into the project’s requirements and expected behavior
Now, I’m not saying software engineers can’t design a good UI; I’ve worked with some world-class developers who just aren’t interested in the UI. They are elbow deep in the core code and like it that way. The straw man gives them something to implement without wasting cycles on front-end design.
On the other hand, a straw man design gives the engineers another take on the requirements and can help round out their understanding of what they should build and how they should implement the back-end design.
In short, the straw man design is a useful tool in your agile process toolkit.