A low fidelity prototype is a prototype where you are intentionally making it not look like a final design. The degree of fidelity you create depends on what you are trying to test. The difference between low and high fidelity isn’t an on-off switch; it is a continuum of different fidelities of prototypes from the lowest quality being a sketched out paper prototype to screenshots put together in Snagit to a photoshop mockup.
When you are trying to test a specific aspect of a project and give someone too many options and information, clients will always focus on the wrong detail if you give them those options. For text, use lorem ipsum or for images, use a placeholder, so they don’t get held up on text misspellings, wrong logos, or grammar errors when trying to get feedback and sign off on the layout. You want to show people the least amount of distracting things.
As you progress further along in a project and get closer and closer to launch, the prototypes should become higher and higher fidelity.
When you are doing prototypes, the goal is to showcase options for a client. You may choose to do low fidelity just for the sake of time. Two-thirds of your work is going to be throwaway work. You don’t want to invest hours into making the prototype look really pretty when it just will be a mock-up.
There is also the curse of a client saying, “that’s not what it looked like in the mock-up.” If you created a prototype too high of fidelity, you might sell your clients on something you can’t easily recreate workably. For example, one professional created a mockup of a website in photoshop, received the CEO’s approval on it, and later realized that the one feature the CEO liked the best was not easy to incorporate and needed to be hand-coded. As a result, he spent three times the amount of time he should’ve spent on the project to add in the one special feature to have it scrapped because it wasn’t maintainable.
Moral of the story: Don’t promise what you can’t deliver, or don’t write checks you can’t cash. Always start with lower fidelity prototypes.