Paper prototyping is the only one truly rapid method of prototyping.
It doesn’t take much time to create basic visualization of your ideas. Actually it’s a matter of minutes. That means that you’re gaining more time for prototyping (and testing!) alternative user interfaces. Create more in less time that’s efficiency which must result in creation of the best interface that you’re capable of.
If we put much effort and time into creating our design we’re immediately getting emotionaly attached to it. That’s the greatest enemy of design in early stages. Hours spent on making complex design in Photoshop, Fireworks, or even Axure, may result in feeling attached to the ideas which weren’t tested yet. Paper prototyping deals well with such problems. It doesn’t take much time to create paper prototype so you can easily put it into bin and start again, or try (and test) different solutions.
Paper prototype is highly collaborative. Just take your team (or even guys from other teams) and work together on the idea. There are no magical skills required. Everyone can easily and quickly prototype on paper. We learned that in the kindergarten.
That’s my favorite merit of paper prototyping. You can easily create interactive prototype which will emulate even the most complicated Ajax functionalities. You’re just moving around pieces of paper it doesn’t require hours spent on writing code.
Finaly: as you can quickly create paper prototypes and making them interactive, you can conduct usability tests on the spot. What’s more, if during tests users will come up with new ideas – you can prototype and test them immediately. Using paper prototyping will give you certainity about your design before you’ll start visualizing it on your computer.
And those advantages are getting even stronger with our paper prototyping kit.