Improvement on Similarity Calculation in Collaborative Filtering Recommendation using Demographic Information

인구 통계 정보를 이용한 협업 여과 추천의 유사도 개선 기법

  • 이용준 (한국전기연구원 전기시험연구소) ;
  • 이세훈 (인하공업전문대학 컴퓨터정보공학부) ;
  • 왕창종 (인하대학교 컴퓨터공학부)
  • Published : 2003.10.01

Abstract

In this paper we present an improved method by using demographic information for overcoming the similarity miss-calculation from the sparsity problem in collaborative filtering recommendation systems. The similarity between a pair of users is only determined by the ratings given to co-rated items, so items that have not been rated by both users are ignored. To solve this problem, we add virtual neighbor's rating using demographic information of neighbors for improving prediction accuracy. It is one kind of extentions of traditional collaborative filtering methods using the peason correlation coefficient. We used the Grouplens movie rating data in experiment and we have compared the proposed method with the collaborative filtering methods by the mean absolute error and receive operating characteristic values. The results show that the proposed method is more efficient than the collaborative filtering methods using the pearson correlation coefficient about 9% in MAE and 13% in sensitivity of ROC.

본 논문에서는 추천시스템에서 많이 활용되는 협업 여과 방법의 문제점으로 지적되고 있는 희소성(sparsity)으로 인한 유사도의 부정확한 문제를 개선하기 위하여, 인구 통계 정보를 이용한 기법을 제안하였다. 두 사용자간의 유사도는 같은 항목에 동시에 평가된 점수를 기반으로 결정되며, 두 사용자가 동시에 평가하지 않은 항목은 유사도 계산에서 제외된다. 제안된 기법은 이러한 평가 점수 부족으로 인하여 유사도 계산이 정확치 못한 단점을 보완하기 위하여, 인구 통계 정보를 이용한 가상 평가 점수를 부가하여 유사도 계산을 개선, 예측의 정확도를 향상시킨 방식으로 기존의 피어슨 상관관계를 이용한 협업여과 방식의 확장이다. 실험은 Grouplens의 영화 평가 자료를 활용하였고, 평균절대오차(MAE)와 반응자 작용특성(ROC)값을 이용하여 제안 기법과 피어슨 상관관계를 이용한 협업 여과 방식을 비교하였다. 제안한 기법이 피어슨 상관관계를 이용한 협업 여과 추천 방식에 비하여 평균절대오차는 9%, 반응자 작용 특성의 민감도는 13% 향상되었음을 확인하였다.

Keywords

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