I love recommendation engines. These are the software that Amazon has everywhere showing “users who bought this also bought” recommendations.
I love them because they are an easy way to leverage the wisdom of the crowd to help users. They also get better the more data you feed into them, so once you set one up, it just makes your site better and better.
For a while, I’ve wanted to explore mahout as a recommendation engine solution, but felt intimidated by how much work integration would be. Luckily, I did a bit of searching and turned up this stackoverflow question about java recommendation engines.
Looking at some of the alternatives, I dug up easyrec, an open source recommendation engine. Rather than solving a couple of different machine learning problems like mahout does, easyrec focuses on recommendations.
Easyrec has support for generating recommendations for more than one kind of item (so if you want to display different recommendations within specific categories of an ecommerce site, that is possible) and is self hostable in any java container (which is recommended if you are going to use it in any commercial capacity). You can also build the recommendations off of the following actions: views, rating, or purchase.
You can also customize easyrec with java plugins, though mahout definitely offers far more options for configuruation.
If you have a set of items that are viewed together, using easyrec can leverage the wisdom of the crowds with not much effort on your part. It’s not as powerful or configurable as alternatives, but it drop dead simple to get started with. It’s worth a look.