While I certainly haven’t conducted any sort of scientific study, it seems like a surprising number of the signal strength indicators on wireless devices consist of the familiar 5 bar layout. Why not 4 bars, or 6, or 3? I believe the answer lies in our natural desire to place things into just the right number of categories.

To see what I’m referring to, pretend that someone asked you to describe your cell phone’s performance in standard terms. You would probably end up with statements like this:

– Really bad

– Sort of bad

– OK

– Pretty good

– Really good

Regardless of the exact terms chosen, I bet that most people would pick about 5 descriptive phrases when faced with this task. If you limit it to 4, there’s no longer a choice right in the middle. Up it to 6 or 7, and it’s hard to distinguish between the degrees of good or bad. 5 is just right.

In case you’re wondering, I haven’t forgotten about 0 bars. Technically, the presence of a 0 bar value adds an extra choice to the mix. However, since this value is usually used to indicate that something is completely off, broken or unavailable, it really doesn’t compete with or take anything away from the benefits of the classic 5 bar design.