All right, you've all been to www.imdb.com. It's the Internet Movie Database; the greatest site on the web. They have all kinds of lists and rankings there: "Top 250 movies", "Bottom 100 movies", best movies by decade, et cetera. However, when you get right down to the nitty-gritty, you'll find that the "user ratings" are difficult to interpret for the non-mathematical mind. What the heck does a 6.8 mean? It's a ways better than average, right?
Nope. It turns out that the average rating is a 6.9. A 6.8 is a slightly below-average movie: a two-and-a-half-star-movie.
First, I designed a fancy-looking spreadsheet which approximated user ratings to help me estimate percentile scores. Then, I translated those percentile scores to a standard 5-star movie rating system, in which 5 stars is a great movie, and 0 stars is a horrible movie that you have no business watching. In this 5-star system, 2.5 stars is an average movie. 3 stars is a good movie--at least better than average.
Because of the origin of the data which I was using, I had to make some modifications to bring the original translation system more in-line with what you'll normally see in a 5-star rating system in your newspaper. There's naturally more 3-star movies than 5-star or 0-star movies, but not dramatically more so. There's not a normal distribution. I had to skew my original system a little bit to get away from the original normal distribution model which I had mimicked. There's still a slight bias to the upper-end of the scale (more 5-star movies than 0-star movies, for example), but it's not extreme, and I think it's now rather fair.
So, here I've provided my User Rating Translation system.
Basically, there are two steps:
1. Look up a movie at www.imdb.com, and check out the "User Rating".
2. Then use the following to translate that to an easy to comprehend star rating.
8.1+ = *****
7.9 to 8.0 = ****1/2
7.6 to 7.8 = ****
7.5 = ***1/2
7.1 to 7.4 = ***
6.8 to 7.0 = **1/2
6.2 to 6.7 = **
5.8 to 6.1 = *1/2
5.3 to 5.8 = *
4.8 to 5.2 = 1/2
1.0 to 4.7 = 0
7.9 to 8.0 = ****1/2
7.6 to 7.8 = ****
7.5 = ***1/2
7.1 to 7.4 = ***
6.8 to 7.0 = **1/2
6.2 to 6.7 = **
5.8 to 6.1 = *1/2
5.3 to 5.8 = *
4.8 to 5.2 = 1/2
1.0 to 4.7 = 0
In case you're interested, I've added my original Excel Spreadsheet showing how I formed my system. It's a little complicated, and not labeled very well, but at least there's something at which to look. It's ----HERE----.
Also, just for fun, I've added a pdf of the 100 worst movies of all time. There are many ways to form this list based solely on imdb user ratings. The method I chose requires a minimum of 4413 user votes to be considered. There is a particular reason I came up with that number, but the reasoning is fairly complicated. It starts with the fact that these are major movies: among the 2000 most-voted-for in the database. Note that the absolute worst is at the bottom of the list, not at the top. In any case, please enjoy this list.
It's ----HERE----.
