Nothing fancy, just simple tag/words based recommendation algorithm implemented in Ruby.
Simple recommendation system written in Ruby
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Simple recommendation system written in Ruby
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Re: Simple recommendation system written in Ruby
#2You may use Levenshtein Distance to get better results by taking word variations into account.
And also you can enhance it by using semantic similarity scores for strings.
Re: Simple recommendation system written in Ruby
#3Programming Collective Intelligence is an excellent book for learning these sort of things. First chapter is a recommendation engine! :)
Re: Simple recommendation system written in Ruby
#4I did something very similar in the past except I used Cosine Similarity (http://en.wikipedia.org/wiki/Cosine_similarity). It allowed me to give each tag a "weight" and when comparing the tag clouds, I would zero out any that aren't found. It works really really well.
Re: Simple recommendation system written in Ruby
#5How well does this perform compared to your postgreSQL example?
Also - We are looking for a Ruby / Backbone.js developer drop me an email josh@seriousfox.co.uk :)
Re: Simple recommendation system written in Ruby
#6I recommend reading http://nlp.stanford.edu/IR-book/ on this topic.
Re: Simple recommendation system written in Ruby
#7if you want something that scales better use minhash. You get a similarity that is approx jaccard but with a lower footprint memory and cpu wise.
Re: Simple recommendation system written in Ruby
#8Programming Collective Intelligence is an excellent book for learning these sort of things. First chapter is a recommendation engine! :)
I second this. And if you decide you want to go really in-depth on recommender systems, I suggest taking a look at "Recommender Systems Handbook" (http://www.springer.com/computer/ai/book/978-0-387-85819-7). It's basically a collection of scholarly articles on on the topic, so the approach is academic. But it's also the best resource I'm aware of for understanding what's state-of-the art across a range of aspects of recommender systems. (Also, although the price is a somewhat hair-raising $179, there are PDF copies of the whole thing floating around that are easy to find with a google search.)
Re: Simple recommendation system written in Ruby
#9You may use Levenshtein Distance to get better results by taking word variations into account. And also you can enhance it by using semantic similarity scores for strings.
If you're willing to get into actual NLP, then semantic similarity would certainly be one way to go. Is there any equivalent to Stanford (Java) or NLTK (Python) in Ruby land? But I'm not sure that Levenshtein will necessarily get you better results than the bag-of-words approach the author is taking with Jaccard distance, if all you're doing is document classification.
Re: Simple recommendation system written in Ruby
#10How well does this perform compared to your postgreSQL example? Also - We are looking for a Ruby / Backbone.js developer drop me an email josh@seriousfox.co.uk :)
Thanks for you comment Josh. In production I actually implemented PG version and it's still in use today. I thought it will scale better and last longer. I didn't do benchmarking or anything like that - it think it would really depend on size of you dataset. For something serious - compute recommendation in background and store them in database. I believe that is how "big boys" do it. :)