Most restaurant critics or reviewers rate restaurants (and movies, hotels and other things for that matter) on scales that don’t really mean very much. Some critics will give scales of 1-10. But this raises a whole slew of questions. It is very hard to know what a restaurant being a 1 means or what a 10 means. If you give a restaurant a 5.0 score, does that mean you liked it or that you thought it was average? What does average even mean? Most restaurants, unless they are particularly bad or expensive, are still fun to go to. So your average restaurant is probably still worth going to if you want to go out and relax. But when we say a restaurant is “mediocre” or “average,” we usually are criticizing it.

Then there are the scales from 1 to 5. These suffer from the same problem except even worse with less granularity. No one wants to give a restaurant a 1 because unless you were poisoned it couldn’t have been that bad. But no one wants to give a score of 5 either unless it was the best restaurant ever. So you are left with 3 scores, plus maybe a couple half points. Don’t get me started on the “thumbs up/thumbs down” measurements. (How can you have “1 and a half” thumbs up? What if you put one thumb up and the other down?)

The “thumbs up/thumbs down” method, while having a granularity problem (not enough variety in the scale), does have one very interesting feature: symmetry. If the reviewer gives 0 thumbs up, we have a good idea of what the restaurant means: “eh” Not so bad that you’ll regret going, but not so good that you’ll just have to go back again. In other words, “average”

Based on this, I’m proposing a new way to rate restaurants (or for that matter movies, hotels, books, or almost anything else). We’ll judge on a scale from -10 to 10. This is more mathematically sound because of the symmetry and effectively is modeled like a “reward” function in machine learning. If a score is greater than 0, then it was worth going to, but if a score is less than 0, it was not worth going to. This score takes into account factors such as cost, distance to travel, etc. So if two restaurants serve the exact same food in the exact same place with the exact same setting, but one costs more than the other, the restaurant with the lower prices will have a better score.

Here is an outline of what scores could mean:

10 – This is one of the top 2 or 3 restaurants you have ever been to of this style food. (In Montreal, Halal 786 gets a 10 for Pakistani, Y Lan gets a 10 for Vietnamese, Olympico gets a 10 for coffee, and Dieu De Ciel for Micro-Brewery.) It is impossible to order something at a 10 restaurant that isn’t incredible. In fact, the best way to eat at these restaurants is by randomly choosing items from the menu as otherwise you’ll always get whatever you got the first time you came to this place. These are restaurants that you’ll go halfway across town (or the country) to get to.

8 or 9. Very, very good restaurant. Not quite worthy of a 10, but pretty darn good. You crave going to this restaurant and will go there whenever you get a chance.

6 or 7. Good restaurant, but a notch below the 8-10, which are really elite restaurants. You won’t necessarily go out of your way to go to these places, but if they are near where you are, you’ll have a fun time there. Examples in Montreal: Cafe Local, EM Cafe, the “up-stairs Chinese place,” the Vietnamese place across the street from Y Lan that I almost never went to because it was across the street from Y Lan. (How did that stay in business anyway?)

3 to 5. These restaurants are still worth going to. They have good food and if you are nearby you may go there. It is unlikely that you will go unless you are specifically feeling like going out that night. You mainly are going here for the atmosphere of going to a restaurant, the convenience of not having to cook, and the convenience of a lot of choices. Once in a while, they’ll surprise you with a really great dish, but for the most part, you can probably cook stuff this good yourself. I would generally say this is an “average” restaurant as an “average” restaurant is still a rewarding experience. Even though you could have cooked the food yourself, it would have taken a long time to put everything together.

1 to 2. You won’t regret coming to these restaurants, but you won’t get very good food. Generally, for a restaurant to end up in the 1-2 category, it will be cheap-otherwise you’d regret coming since the food isn’t all that special. Either that or it used ingredients that would have been difficult or annoying to find.

0. No gain, no loss

-1 to -3 : This restaurant was bad. You left and feel like you wasted your money. You could have cooked this yourself and it would have been cheaper and tasted better. You will never come back to this place again unless one of your friends drags you to it.

-4 to -6: The food was terrible, the service was incredibly slow, and the place was overpriced. (They ran out of baked potatoes! The ice cream was melted once they gave it to me! The waiter spilled salad on me and I was happy because I didn’t have to eat it!) You won’t come back to this place again unless your friend convinces you that the head chef was sick that night and the restaurant changed ownership.

-7 to -8 : One of the worst restaurants that you have ever been to. You still have nightmares about that weird mystery meat they served you.

-9: Gave you E Coli or some other stomach problem.

-10: After trying one taste of their specials, you immediately get up and leave because the food is that bad. Even that one spoonful, however, is enough to make you sick, and you spend the next week working up the nerve to go outside.

One other interesting thing about the scale is you may have to make it context-dependent (yes, this sounds like my work at school). For example, I’m not a big fan of Subway normally. I think their sandwiches cost more than they should since I can usually make them myself. I’d normally give Subway a score of 1 or 2. (I only give the points because it would have been wasteful for me to buy the many kinds of meat that they offer.) However, at a rest stop on a road trip, I’d give subway a higher score. Maybe 5 or 6. I know that it won’t make me sick, it will be pretty healthy, and I know what to expect. When I see a Subway sign on the highway around lunch, I generally will go there.

Well, that’s my food scale. I will be using this food scale from now on in rating restaurants.