A user prototype—one of the most powerful tools in product discovery—is a simulation. Smoke and mirrors. It's all a façade. There is nothing behind the curtain. In other words, if you have a user prototype of an e‐commerce site, you can enter your credit card information as many times as you want—you won't actually be buying anything.
There is a wide range of user prototypes.
At one end of the spectrum are low‐fidelity user prototypes. A low‐fidelity user prototype doesn't look real—it is essentially an interactive wireframe. Many teams use these as a way to think through the product among themselves, but there are other uses as well.
Low‐fidelity user prototypes, however, represent only one dimension of your product—the information and the workflow—there's nothing there about the impact of visual design or the differences caused by the actual data, to mention just a couple of important examples.
At the other end of the spectrum are high‐fidelity user prototypes. A high‐fidelity user prototype is still a simulation; however, now it looks and feels very real. In fact, with many good high‐fidelity user prototypes, you need to look close to see that it's not real. The data you see is very realistic, but it's not real either—mostly meaning it's not live.
A user prototype is key to several types of validation and is also one of our most important communication tools.
For example, if in my e‐commerce user prototype example, I do a search for a particular type of mountain bike, it always comes back with the same set of mountain bikes. But if I look closely, they're not the actual bikes I asked for. And I notice that every time I search, it's always the same set of bikes no matter what price or style I specify.
If you are trying to test the relevance of the search results, this would not be the right tool for the job. But if you are trying to come up with a good overall shopping experience or figure out how people want to search for mountain bikes, this is probably more than adequate, and it's very quick and easy to create.
There are many tools for creating user prototypes—for every type of device, and for every level of fidelity. The tools are mainly developed for product designers. In fact, your product designer almost certainly already has one or more favorite user prototyping tools.
It's also the case that some designers prefer to hand‐code their high‐fidelity user prototypes, which is fine so long as they are fast, and they are willing to treat the prototype as disposable.
The big limitation of a user prototype is that it's not good for proving anything—like whether or not your product will sell.
Where a lot of novice product people go sideways is when they create a high‐fidelity user prototype and they put it in front of 10 or 15 people who all say how much they love it. They think they've validated their product, but unfortunately, that's not how it works. People say all kinds of things and then go do something different.
We have much better techniques for validating value, so it's important that you understand what a user prototype is not appropriate for.
This is one of the most important techniques for product teams, so it is well worth developing your team's skills and experience in creating user prototypes at all levels of fidelity. As you'll see in the coming chapters, a user prototype is key to several types of validation and is also one of our most important communication tools.