But if I want to quickly decide if a movie is worth watching, looking up its IMDB score is a blunt but fairly decent instrument. I'm not going to read reviews of 10 movies, usually.
Personally, I most enjoy watching reviews after I've seen a movie anyway, to get a critic's take on the movie I enjoyed (or didn't).
Before it got killed by Amazon, one of the best things about LoveFilm was that it showed the distribution of user scores for each movie. For many movies the distribution was normal (peak in the middle) and those movies were usually "OK" ... but the interesting ones were the "marmite" movies with lots of 0s and 5s. Both sets would have the same average score, but you could gamble on the marmite ones and maybe get a great movie with a 3 average.
Yeah, it really depends on why you are evaluating these scores.
If it's simply to answer the question, "what will the wife and I watch tonight?" and you're presented with a algorithmically limited set of options based on your viewing habits and your up/down votes, yes, I think scores are a "good enough" blunt instrument.
If you want to explore the work of a particular director, genre, theme, period or actor but don't want to just watch all those films chronologically (or by only viewing "the blockbusters") then reading a bunch of reviews will help A LOT. The scores in that scenario would then merely be trite factoids.
But if I want to quickly decide if a movie is worth watching, looking up its IMDB score is a blunt but fairly decent instrument. I'm not going to read reviews of 10 movies, usually.
Personally, I most enjoy watching reviews after I've seen a movie anyway, to get a critic's take on the movie I enjoyed (or didn't).