This post was previously on the Pathfinder Software site. Pathfinder Software changed its name to Orthogonal in 2016. Read more.

High-fi, low-fi, or something in between? Choosing the right fidelity for a prototype is crucial to effectively use the limited resources of your project. Low fidelity prototypes, such as hand sketches, are fast and enable more iterations. High fidelity prototypes, however, might better engage an audience for feedback.

To choose the right level of fidelity, consider the following five questions:

Who is the audience for this prototype?
What is the one most important purpose of this prototype?
How many iterations of this prototype are necessary?
How much uncertainty is there in the project at this stage?
What tools can be leveraged to create the prototype?

Let’s explore each of these.

Who is the audience for this prototype?
You should not prototype at a level your audience will not understand. If your audience can understand hand sketches, great. That gives you more options. If not, identify the lowest level of fidelity comfortable for your audience. If the lowest level is fairly high, you may need to prototype fewer screens or ideas.

What is the one most important purpose of this prototype?
Prototypes should almost always be focused on one purpose. Are you testing an idea to see if people understand it? Are you evaluating the organization or navigation of a UI? Even if your prototype must do a few things, figure out the most important to help determine the proper fidelity.

How much uncertainty is there in the project at this stage?
When a project has a lot of uncertainty, often it is best to prototype quickly and get some feedback. It’s likely in this kind of situation lower fidelity prototypes should be used. When the idea or direction of the project is more certain, a higher level of fidelity may be best to help refine specifics.

How many iterations of this prototype are necessary?
Often prototyping is most useful when a sequence of prototypes can be done in rapid succession. Each builds on the learning and discoveries from the previous iteration. When choosing a fidelity, consider the benefit of doing more iterations at lower fidelity.

What tools can be leveraged to create the prototype?
There are lots of great prototyping tools out there with more coming online all the time. Many are free or available at a modest cost so it pays to do a search every now and then to see what’s available. When looking at tools, though, be sure to consider the speed with which a new tool can be learned and used effectively. Where speed is a high priority, sometimes familiar tools are the best way to go or those simple enough to use immediately with no learning curve.