type creation if you're working mostly
from screen shots, and up to a week if it's a new interface
or a complete redesign. Any more than a week and you're
spending too much time polishing the design before getting
user feedback. (The other activities associated with planning,
preparing, and conducting a handful of usability tests typically
take on the order of a week of hands-on time, spread out over
Sometimes paper prototyping will uncover planned functionality
that doesn't need to be implemented. For example, I once tested
a paper prototype of a distance learning Web application. The
original design called for users to have avatars to navigate the
virtual classroom, raise their virtual hands, etc. In prototype
testing, we quickly learned that all this virtual 3D stuff got
in the way of the real purpose of the application, which was
to enable large companies to provide training to geographically
dispersed employees. The designers realized that they were
jeopardizing their whole product concept by trying to make the
application feel like a video game. They dropped the 3D
functionality, which actually shortened their development
schedule. This was five years ago, and the product is still
around, sans 3D.
It's normal for interfaces to undergo substantial changes between
the initial concept and the actual release. No one enjoys writing
code that ends up having to be overhauled or scrapped. Paper
prototyping lets you find significant problems early in the
design process, so you can experiment to find the best solution
before investing the effort to implement it.
problem identification using both low- and high-fidelity
prototypes by Robert Virzi, Jeff Sokolov, and
Demetrios Karis is available from the ACM Digital Library.
(You must be an ACM member or pay a US$10 fee to download
Read the author's list of useful
supplies for paper prototyping, including hard-to-find
items like removable tape. Includes links to specific items on
two office supply Web sites.
Practical Guide to Usability Testing
by Joe Dumas and Ginny Redish is a good introductory
reference for usability testing.
The Society for Technical Communication maintains a
in Usability site containing resources on
From User Interface Engineering's site, see the articles
Paper Prototype Tips by Matthew Klee, and
Paper Prototypes to Manage Risk by Carolyn Snyder.
Check out Carolyn Snyder's article
Seven Tricks that Web Users
Don't Know to find out what you may be taking for
granted about your users.
Snyder Consulting * (603) 216-2255 *
csnyder at snyderconsulting dot net