Prototyping is the most effective way to evaluate design for me now. First of all as a designer it is a great chance to see a project AS IT IS IN LIFE and figure out what users or customers need early in the design process. Regardless of the specifics of the goal, a prototype is the best way to present a final design or test a user’s “journey” and fulfill an idea in a matter of few weeks instead of months.
My criteria for a good prototype
Adaptivity
One of the most crucial characteristics is that a prototype should be easily adaptive, in a sense that new features could be added to the sample, or a new UI design applied. The prototype is a living structure that continues to evolve further even when the project is accomplished. It may still be subjected to changes and updates, having a variety of prospects ahead- that’s how I know that my project has been successfully realised.
Build-up
At any moment in time, the work on the prototype may be delegated to other designers, without any setbacks in terms of quality and time.
Visual “niceness”
Even if it is a low fidelity design, it should look nice and create a wow-effect, because the prototype in itself is a step towards improvement (upgrade), implementation of something new - product, feature, technology.