Over the past month, I’ve come across the same discussion several times: “When designing a website or product, do you use wireframing or prototyping?”
The first part of my answer is: “Make sure you sketch, first.”
At the design stage, sketching, wire-framing, and prototyping are not equal. Sketching is useful at the divergent phase of design because it lets the design participants express and capture lots of different ideas quickly and anywhere that pen and paper will work. Nothing is as fast as running a pen across a sheet of paper to capture an idea—and then another, and another. And since sketching is intentionally rough, everyone can do it.

Responding to the problem statement, first saturate the design space with lots of ideas, and then analyse and rapidly iterate them to a design solution.
I also believe sketching is great for the convergent phase of design, but there are potential hurdles that design participants may encounter. It can be challenging to convey complex interaction, 3D manipulation, transitions, and multi-state or highly interactive GUI in sketches without learning a few additional techniques. This is unfortunate, because having to learn additional techniques reduce the near-universal accessibility of sketching.
The second part of my answer, therefore, is that “if you need to learn additional techniques to make sketching work, feel free to choose wireframes or prototyping as alternatives when there are compelling reasons to do so.”
I should point out that the three techniques—sketching, wireframing, and prototyping—are not mutually exclusive. Wireframes and paper prototypes can both be sketched—especially for simple or relatively static GUI designs.
There are no validity concerns with the use of low-fidelity sketches, as these readings show:



Today, I watched a video of people helping a motorised cardboard construction or “robot” to navigate. The so-called tweenbot has a flag on it that says “Help me,” and that asks people to send it on its way to its outdoor destination.
some measurable outcomes (requirements, metrics, or goals), access to a subject-matter expert to answer questions about the domain and perhaps to present a competitor analysis.
I can hear your clients and your managers saying: “Well, Mr Buxton may have told you that you have to be able to do five different versions for every single question you’re asked—each one equally valid—but we can’t afford it because we’re already behind schedule. We don’t even have time to do one solution, and you’re telling me we have to do five?”
have a pen and paper, so there’s no need to wait your turn. Sketching is fast, so designers have little invested in any one sketch. Modifying or iterating any one of the ideas is easier to accept. Most importantly, for inexpert sketchers, the sketching process intrinsically discourages high-fidelity work and the wide-nib pen discourages sketching the fine detail that detracts design participants from getting the ideas out, fast.