During several months since I came to DT, "prototype" may be one of the most frequently used words in daily conversations. As Stephanie Houde and Charles Hill say in their article, "It is a common practice to build prototypes in order to represent different states of an evolving design, and to explore options." From my own perspective, prototyping serves as three main functions: testing, representing, and evaluating. With the help of various types and levels of prototypes, designers are able to iterate, understand and present their ideas better both to themselves as well as to the audience.
Prototypes are mainly categorized into three types: Role, Implementation, and Look and Feel. While the final outcome should have an integration quality containing all the features above. Though sometimes it is hard to put one particular prototype into only one category; more commonly, it would be a combination of either two or three of the roles. For instance, in the early stage of my final proposal, I want to make a visual representation of people using social media as a platform for collaborative protest. What I've done at last can be regarded as both a look and feel prototype, as well as a role prototype.
Besides, it is important to figure out the target audience and the goal of a prototype, because each group of people would have different expectations and perspective to the project. Is it designed for designers, steak holders, developers, or target users? If the target audience are developers, what would be the best way to present ideas? If the target audience are steak holders, how can we show them the most valuable part of the idea without causing any misunderstood? Once the audience and the goal of a prototype is well defined, it will be easier to build, test and get feedbacks from it.
In a word, prototypes can be used as a great tool for testing, representing and evaluating ideas. The most important thing is to narrow down the concept and clarify the goal of each prototype as much as possible.