This could be used for films, music and perhaps other subjects. Let's say films for starters. A user registers on a website, and is asked to browse a list of films and give a mark out of ten to any they have seen and have any feelings for. They can mark as few or as many as they like, but for an accurate a service as possible they should fill out as many as they can, and then update their list as they see more films.

The user will then be able to request a review of a film they haven't seen. The rating of the film is obviously based on the reviews of other users, but the marks are calculated using weightings. Marks from someone who seems to generally like the same kind of stuff as you you are given a higher weighting than those from people who generally disagree with you. This way, you get to find out what a like-minded person would make of the film. I haven't really thought very much about the statistical and algorithmic details of this, admittedly.

The intention is to empirically determine how much people like something without having to worry about details. You might not even not be able to really put into words what it is that you like about a particular film, and it is my belief that someone else who also feels this way about the film will probably have similar reasons for liking it. The system would require quite a lot of data to be of any use, but once it's up and running it could be quite useful. For instance, you're at the video shop and you want to know what someone "like you" would make of a film. You could SMS your user number and film title to the service and get back a personalised rating. Might hopefully reduce incidence of the phenomenon of renting out a film that got a glowing review and finding that you think it blows.

I am unaware of anything like this in existence, but suspect that it's out there somewhere. *Sits back and awaits cries of "This is so baked it's burnt the house down"*.
-- sild, May 19 2003

Oh No! My Tivo thinks I'm Gay! http://online.wsj.c...36872356908,00.html
Some interesting anecdotes of when this type of technology behaves in unexpected ways. [krelnik, Oct 05 2004]

Amazon.com, Netflix... all work like this. IMDb has this functionality as well.
-- waugsqueke, May 19 2003


Sounds good to me (+)
-- silverstormer, May 19 2003


<obligatory>This is so baked it's burnt the house down.</>

I'm one of those folks who has had an excellent experience with Amazon's implementation of this. Their music store has suggested several artists I was previously unaware of, all of whom I've liked.

I've found the key to this working really well is to be proactive, especially if you don't buy everything through Amazon. Visit the purchase pages of items you already have and like, and you'll find a widget down on the page (usually lower left or lower center) that says "Rate this item". Check whether you own it and give it a rating.

If you do that religiously when you buy things that are in Amazon's store, it will get incredibly smart about recommending things to you.

//system would require quite a lot of data to be of any use//
Yup, I think that's key and I think that's why the ones at the big stores like Amazon and CDNow actually work quite well, because they do a huge enough volume to have this level of data available.
-- krelnik, May 19 2003


Hmm, I had considered the Amazon recommendations system but decided that it was different. Thinking about it though, I suppose the "Customers who bought this also bought this...." is pretty much the same as this idea if you assume that what they recommend are the best-sellers in that genre, and therefore effectively the top rated items.
-- sild, May 20 2003


//I'm one of those folks who has had an excellent experience with Amazon's implementation of this...//

[krelnik] Same here - I started using the Amazon rating system in the early 90's when it was www.firefly.com (don't look for it, it's not there any more) and it was excellent then.
-- hippo, May 20 2003


The Amazon system works almost too well. It keeps recommending things I already have. At least it was correct in thinking I would like them. (I know you can check "I already own this", but I got tired of having to tell it everything I own.)
-- waugsqueke, May 20 2003


Yeah, I've always thought they should add something to make doing that more attractive to the end user. Like a free service to keep track of your DVD/CD/book/etc collection online, but the side effect is it marks all these items as "I have it" in your Amazon profile too. That way you'd have incentive to enter the data (insurance purposes, print a catalog, search your collection) and Amazon would get alot of interesting data to base suggestions on.
-- krelnik, May 20 2003



random, halfbakery