Kurt Kohlstedt
99% Invisible
A Podcast by Roman Mars & Kurt KohlstedtInheriting Froebel's Gifts
A Podcast by Kurt KohlstedtFroebel’s Gifts were meant to be given in a particular order, growing more complex over time and teaching different lessons about shape, structure and perception along the way. A soft knitted ball could be given to a child just six weeks old, followed by a wooden ball and then a cube, illustrating similarities and differences in shapes and materials. Then kids would get a cylinder (which combines elements of both the ball and the cube) and it would blow their little minds. Some objects were pierced by strings or rods so kids could spin them and see how one shapes morphs into another when set into motion. Later came cubes made up of smaller cubes and other hybrids, showing children how parts relate to a whole through deconstruction and reassembly.
These perception-oriented “Gifts” would then give way to construction-oriented “Occupations.” Kids would be told to build things out of materials like paper, string, wire, or little sticks and peas that could be connected and stacked into structures.
The 99% Invisible City
A Book by Roman Mars & Kurt Kohlstedt
The Fidelity Curve
How do we choose which level of fidelity is appropriate for a project?
I think about it like this: The purpose of making sketches and mockups before coding is to gain confidence in what we plan to do. I’m trying to remove risk from the decision to build something by somehow “previewing” it in a cheaper form. There’s a trade-off here. The higher the fidelity of the mockup, the more confidence it gives me. But the longer it takes to create that mockup, the more time I’ve wasted on an intermediate step before building the real thing.
I like to look at that trade-off economically. Each method reduces risk by letting me preview the outcome at lower fidelity, at the cost of time spent on it. The cost/benefit of each type of mockup is going to vary depending on the fidelity of the simulation and the work involved in building the real thing.
Four levels of fidelity
Suppose we have four levels of fidelity…
- Rough sketch (on paper or an iPad)
- Static mock-up (eg. Photoshop or Sketch)
- Interactive mock-up (eg. Framer, InVision)
- Working code prototype (HTML/CSS, iOS views)
Depending on the feature you’re working on, these levels of fidelity take different amounts of time to create. If you plot them in terms of time to build versus confidence gained, you could imagine something like a per-feature fidelity curve.
Time to build versus confidence gained
Take a simple CRUD web UI, where you’re just navigating between screens. It doesn’t take much more time to build the real version than it does to mock it when the design is simple. If you were to build out an interactive mock first, you would end up spending twice as much time in total without gaining much out of it.
Contrast that with a complicated Javascript interaction. Or a native iOS feature that requires programmer time to build out. If it takes substantially more time to build the real code version, then it may be smart to do an interactive mockup first.