Introduction - Paper Prototyping: The Fast and Easy Way to Define and Refine User Interfaces - page 6

What Paper Prototyping Isn't
There are three techniques—comps, wireframes, and storyboards—that people commonly confuse with
paper prototypes. These techniques are useful, but they usually don't fit my definition of a paper
prototype, although all of them can be turned into paper prototypes. Here's a bit more explanation.
Comps
Comps (which is short for compositions ) are visual representations—usually of a Web site—that show
the look of the interface, including colors, fonts, layout, logos, artwork, and so on. ( Figure 1.9 shows a
sample of some comps.) The graphic designer or agency responsible for the visual aspects of the
design might make several variations of the interface, allowing the decision makers to pick the one that
best supports the current business initiatives, conveys the brand, and so forth. Some comps use
nonsense words to represent the text and links. Comps are primarily used in internal discussions of a
site's visual design; they usually are not intended (or suitable) for usability testing because users can't
interact with them. However, if comps contained realistic content and were printed out, they might then
fit my definition of a paper prototype.
Figure 1.9: A set of comps for the home page of PlacesToStay.com. Comps are used to explore
different layouts, graphics, and visual emphasis. Unlike this example, some comps use nonsense
words for text and links.
Wireframes
Like paper prototype, wireframe can be a confusing term because people use it to mean different
things. A wireframe defines the page layout for a Web site, showing what content goes where. ( Figure
1.10 shows an example of a wireframe.) In the early stages of designing a Web site, wireframes are
used in determining the page layout and navigation. But is a wireframe a paper prototype? It depends.
Some wireframes designate the major areas on the page with labels (for example, "product
information") but don't contain any content. This type of wireframe is sometimes used to get feedback
from users, but this approach is of limited benefit because it's hard to tell whether the user's
understanding of "product information" is the same as the designer's. Thus, a wireframe without
content doesn't quite fit my definition of a paper prototype. On the other hand, with the addition of
realistic content a wireframe could be printed out and tested as a paper prototype. In that case I would
classify the wireframe as a paper prototype.