But we've learned that the prototype itself is more than a disposable instrument to gather design changes. Teams increasingly use paper prototypes to help generate requirements. Every time they test a design, they uncover new requirements. By having real users do real work with the prototype, they end up with more accurate requirements than any other process would give them. It can be labor-intensive to create a paper prototype, especially the first one.
Paper prototyping is sometimes easier with a larger team, because the work can be shared.
With only one or two developers, it's necessary to block out more time to create the initial prototype. Teams we've worked with take an average of about 12 hours to create their initial paper prototype. We've also learned that HTML is almost as fast as paper prototypes, especially if the team is small and proficient with the tools. We occasionally use it as an alternative. However, if the project has lots of graphics or uses more than plain-vanilla HTML, it probably makes sense to use paper.