So it turned out computers could be pretty dumb. You enjoyed that article about beach volleyball at the Olympics? Right! From now on, a volleyball article every time you come back. Forever. You read that insightful analysis on the problems of overfishing? Environmental news and nothing else for you.
After a few years getting annoyed with this issue it was time to tackle it: how to recommend things in appropriate proportions. Many clever algorithms, experiments and publications awaited.
Unfortunately for my scientific career there was a much simpler solution. At the time my girlfriend was working on a project for a large food company to test a machine that made custom mixes of ingredients for a particular product. They needed an interface to control the proportions of things. It turned out that was the inspiration I needed. No clever algorithms required, just a nice interface. A very important lesson indeed!
So I made the Slider interface. News comes in. If you drag articles to the different panels, and name them, you effectively get different sections of a newspaper. If you want more or less of a section, you just slide that panel up or down. Don't like something - bored of volleyball now? Drag it to the trash. The panels locked together nicely so you could drag a bunch of them together - all Java graphics running on a Sun workstation.
Behind the scenes the system learned a profile for each section of your newspaper. Simple. Effective. It worked. Not as many publications for me as the other approach though.