I'll take the time to respond here, but you really should do a forum search to find past discussions about the curve. Anyway, it's pretty simple if you've ever seen a MCAT score report.
To start off, there are always going to be a fixed percentage of people who get a certain numerical score in a single section. It works in terms of percentiles. You get a score based on your percentile performance which means you're given a score relative to the other people who took the same test. Standardized testing for the most part is based on percentiles and the MCAT is no exception. This is a given, and I am sure most people understand this.
What's next is a little nebulous but I'll give you my take. BerkReviewTeach has made a very informative post yesterday, that if you search for it, sheds some light on how prep companies approach the standardization aspect of exam administrations. They look at individual test items and see if there are any serious deviations from the expected standard distribution for a single item. I don't know exactly what the criteria is, but if it is way off, they may throw said item out. Generally though, the overall picture will paint a bell curve, placing people in a neat distribution from which numerical scores are determined by percentile. I am assuming this is what everyone means when they talk about the curve. Depending on which questions are thrown out, you may benefit or you may be hurt by the 'curve'. This may be more and more random these days, given that there are so many administrations in one year now. Who knows. I agree that I wouldn't spend a great deal of time worrying about how the curve is determined or whether one would benefit or be hurt by said curve.
But it is informative to know what you're up against, and in that respect I think that's more or less what you need to know. Search BerkReviewTeach's recent posts and you'll find more specific information. Hope this helps.
