I remember those early systems, and was in touch with Upendra Shardanand and Pattie Maes at the time. Other early systems ca

As music recommendation was already being done, I developed MORSE, short for MOvie Recommendation SystEm, shortly after Ringo appeared. Like Ringo and Firefly, it was a collaborative filtering system, i.e. it worked by comparing how similar your tastes were to the tastes of other users, and took no account of other information (e.g. genre, director, cast). As it was a purely statistical algorithm, I didn't call it, or other collaborative filtering systems, AI. It was different to symbolic AI (which I was previously working on, in Prolog and Common Lisp), didn't use neural networks, and wasn't Nouvelle AI (actually the oldest approach to AI) either. I wrote it in C (it had to run fast and was just processing numbers) and used CGI (Common Gateway Interface) to collect data and give recommendations on the WWW.

In a nutshell, to predict the rating for a film a user hasn't seen yet, it plotted the ratings given by other users for that film against how their ratings correlated with the the user, found the best-fitting straight like through them and extrapolated it, estimating the rating of a hypothetical user whose tastes exactly matched the user for the film. It also calculated the error on this, which it took into account when giving recommendations. Other collaborative filtering systems used simpler algorithms which ignored the ratings of users whose tastes were different. When I used those simpler algorithms on the same data, recommendation accuracy got worse.

MORSE was released on the BT Labs' web site in 1995. It survived a few years there, but was later taken off the server. As BT Weren't going further with it, I asked if the source code could be released, This was agreed, but it wasn't on any machine, and they couldn't find the backup tape. The algorithm is described in detail here: https://fmjlang.co.uk/morse/morse.pdf and more general information is here: https://fmjlang.co.uk/morse/MORSE.html

My algorithm was pretty similar to yours I’m guessing. (See my other long post here.) I described mine to a friend one time and he called it “toothpick AI”.