In this rating system, there are many advantages. First, you can quickly tell if something is good (positive) or bad (negative) with ZERO being average. This makes the system have an odd number, which is important so a rating can be exactly in the middle. Next, we went with lots of levels between them for accuracy. If all a reader knows is that we liked it or didn't like it, how will they know if we HATED it? Ten positive and ten negative allows for a good quick system without too much craziness.
Obviously, I believe this is superior to all other rating systems, otherwise, I wouldn't use it. So how does it compare to some of the most used systems in society? Here are a few to compare:
Thumbs up/down
The benefit of like/dislike is that it's simple and clear. But when evaluating the total likes/dislikes, we still break it down with how many. 600 thumbs up and 1000 thumbs down is the data we really want, which is no longer simple. And how do we know if the 600 people really liked it while the 1000 people just had minor issues to say, "Yep! It's good!" The worst part is that there's no way to say, "Meh." Do you really have to like or dislike everything? Can't something just be ok?
Five Stars
This is one of the most used systems on the internet, but it drives me crazy! First of all, you can't tell by looking at the rating whether you can give something zero stars if you hate it. So if something has three stars, is it above average or just average? There are three full stars and only two stars missing, so shouldn't 2.5 stars be average? UGH! Not only that, some cultures have a hard time evaluating something as "Perfect" or "Worst", which some see as implied with five stars or zero/one star. For that person, there are really only three choices now: Like, Dislike, or Meh. In a way, that makes it better than Thumbs Up/Down, but it loses the simplistic clarity.
Benefits of -10 to +10
First of all, it's obvious if you liked it or not, just like Thumbs Up/Down. If it's a positive number, you liked it, negative you didn't. If the scale was, say, 1 to 10, you lose that simplicity. Also, it's not clear if you have a rating of 5/10 whether you can rate something as a zero or not. So you lose clarity. You also have a large scale, so if someone refuses to use the extremes of -10 or +10, they can still show they loved it or hated with 9 or -9. One of the most important aspects of this scale is that it can have a zero. It is so clear what is average using a rating scale that has a middle.
So that's why we use -10 to +10. What do you think? Let us know in the comments!