Content based filtering methods like the NLP and audio analysis approach can be used to diversify the results that you'd get from collaborative filtering (or ad

Content based filtering methods like the NLP and audio analysis approach can be used to diversify the results that you'd get from collaborative filtering (or add 'noise' to recommendations, as someone up the thread wished for). I'm guessing they evaluate in many ways. E.g. play counts for online evaluations, accuracy compared to some ground truth for offline evaluations