During freshman year of college, I had a physics professor who would mark a test answer wrong if there was no unit of measurement specified for the answer. Didn’t matter if the number given was clearly the correct answer, no units meant no points.

At the time I thought he was an anal-retentive old man who enjoyed giving us one more unnecessary hoop to jump through for an A. Obviously, I was wrong. By senior year, I too was considering numbers without units to be invalid. There’s a big difference between 6 volts and 6 amps. (Difference: one is good to power a flashlight, the other will cause cardiac arrest.) So that’s why you’ll never see a number on ParkWhiz that doesn’t have a unit of measurement attached to it.

But it’s not enough to have units, they need to be the right units. I can name all 50 states in 7.92219116 × 10-7 years. That’s pretty fast, right? No? You’re not sure?

When ParkWhiz first launched, we expressed the distance from a parking spot to your destination in feet. Lucky for us, a couple users quickly pointed out that they didn’t know how far 1274 feet was. Our choice of units rendered the measurement meaningless.

We’ve since switched to measuring distance in “walking minutes”. If someone is parking their car, they’ll probably be walking the rest of the way to their destination. They don’t care about the actual distance; they just want to know how long it will take them to walk that distance. We settled on an estimated walking speed of 3 miles/hour. It’s a quicker than average pace, but we figured that people use ParkWhiz to get to their destination fast; they’re not going to waste time strolling the rest of the way.

What do you think? Is it better to provide an “interpreted unit of measure” instead of an absolute unit like feet or miles?

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