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Building Better Wizards

Wizards are becoming more and more prevalent. Lest you’re concerned that Dumbledore’s relatives are coming to exact revenge, fear not: we speak here of wizards in the GUI (as opposed to gooey) sense. Yes, there are bastions of holdouts that cling to command line interfaces as a measure of their hacker bona fides, but there are solid reasons to like a well-designed wizard.

And “well-designed” is the operative phrase here. You may think of a wizard as no more than a way to simplify processes that could just as effectively be done using the command line if only you were boss enough to remember all the arcane intentionally-obscure commands required to get stuff done. And in some cases, such automation is the goal. But the potential goes beyond that: it’s an opportunity for a world-view transformation.

This is a favorite old topic of mine, but it was refreshed for me while watching a Movea SmartFusion Studio demo: when assembling a sensor fusion algorithm, a wide variety of filters are made available. And I thought, “How do you know which filter to pick??”

Now, you could easily argue that, if you don’t know your filters, then you have no business getting involved in sensor fusion. Perhaps. But really, a designer is interested in a behavior, not necessarily in knowing the details of how that behavior is implemented in some specific algorithm or circuit.

This became really clear to me several years ago on a consulting project where I was designing and prototyping a wizard for a piece of communication IP. The IP was very flexible, so there were lots of options that the user, who would be a system designer, could tweak. The obvious first approach to the wizard was simply to provide option fields for the user to fill in.

Being a communication protocol, it had FIFOs for elasticity; the user could dial up how big those FIFOs were to be. So I put a text field there for the size of the FIFO. But I asked the designers of the IP, “How should the user figure out how big the FIFO should be?” My first thought was that this information would be useful in the user manual. (Stop laughing… I’m sure someone reads those…)

They answered that the user would decide how many packets they wanted to buffer; that and the selectable packet size would determine the FIFO size. Simple enough.

But then I thought, “Wait, why are we making the user of this wizard do some paper-and-pencil calculations before going back to the computer? What if, instead of asking for the FIFO size, we asked for the number of packets?” The wizard already had the packet size somewhere else, so it then had all the information needed to calculate the FIFO size. No paper or pencil required.

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