Abstract: Collaborative filtering recommendation algorithm is one of the most successful technologies in the e-commerce recommendation system. This paper presented a collaborative filtering algorithm based on co-ratings and similarity weight. First, the co-ratings were selected to compute the similarity between users or items. Most importantly, the algorithm acquiring the last prediction result was acquired by combining prior predicting rating with similarity weight,from which recommendation was produced. The experimental results in real data show this algorithm can consistently achieve better prediction accuracy, thereby brings better recommendation quality.

Key words: E-commerce, Recommendation system, Collaborative filtering, Co-rating, Similarity weight