My first experience of Paper Prototyping was in the development of a User Management System. I had suggested to my product development team that we use this technique, as the key issues we had identified in the requirements analysis process were usability related.
It really is an amazing process; we yielded 13 usability errors in the initial design in the first 30 minutes alone. By the end of the afternoon we had redesigned the system and had a completely new and improved prototype to put forward, one that met all the usability requirements of the user.
Paper Prototyping is a low-tech approach to Usability Testing, that adds value at the begining of the software development lifecycle. Paper-prototyping.com calls it 'The fast and easy way to design and refine user interfaces.'
You draw your designs on paper and get someone to 'play' the computer, while someone else plays the User and it helps if you have someone taking notes too! You give the user specific tasks to complete and can overcome any hurdles as you go, by re-drawing the system on the fly.
Paper Prototyping is a usability tool. It needs to be used in conjunction with other analysis methods to produce a fully-fledged spec document. However, as the initial tool in the design process (not including initial requirements analysis) the only downfall I have found is in modelling the actions of truely dynamic components such as search functions. The best way to overcome this limitation is to give the 'user' specific tasks that you have prepared results for.
The key reasons I find this tool so useful are that it's:
The old adage that you can have any 2 from 'cheap', 'quick' and 'good' is broken by this tool. This is one of the cheapest tools you'll find, basically and afternoon and a bit of stationary, and you get good results very quickly.
It's quick to set up, after all you just need to order stationary. And once you have that, an afternoon often heeds better results than weeks of traditional prototyping methods.
One of the most important benefits of this system is that it's fun - an oft neglected attribute at work! What it means practically is that people will actually use the tool, they want to get involved for an afternoon. Once people are into it, I've found that they compete to analyse problems more fully, they think more laterally, and certainly bond too. These are things that are notoriously difficult to pin down in any project, and are therefore, very valuable! I've also found that these results from Paper Prototyping feed into the Business Analysts everyday work improving the overall quality of specification improves.
Paper prototyping is a fun way to spend an afternoon, so even if you try it and completely disagree with me: give it a try. What have you got to lose, except an afternoon and a bit of stationary?