What exactly do I mean by unitless numbers (UN)? I mean when things are labels with numbers but have no specified units.For example, a volume control that goes from 1 to 10 is unitless. The units should be in decibels.
Designers of electrical appliances are in love with using UN. Pretty much everything has this. The monitor I’m using lets me set brightness on a level from 0 to 100 – these units should be in lumens. The electrical oven I have uses a dial that goes from 0 to 8, here it should use wattage.
Using the appropriate units educates the user about how to measure the strength or output of the device. By using UN you force the user to learn your specific configuration. One brightness scale could go from 0 to 10 and another from 0 to 100 yet have the same brightness at 10 and 100. When I first see UN used on an appliance for the first time, I have no idea of what level I want it at so I have to learn what the units mean. I don’t have an infinite amount of space in my brain. Precious neurons are wasted translating “low, medium, high” to “200W, 300W, 400W”.
This is a call to all those in design jobs. Avoid UN like the plague. There is no reason to use them.