Exploring the semantic gap for movie recommendations

In the last years, there has been much attention given to the semantic gap problem in multimedia retrieval systems. Much effort has been devoted to bridge this gap by building tools for the extraction of high-level, semantics-based features from multimedia content, as low-level features are not considered useful because they deal primarily with representing the perceived content rather than the semantics of it. In this paper, we explore a different point of view by leveraging the gap between low-level and high-level features. We experiment with a recent approach for movie recommendation that extract lowlevel Mise-en-Scène features from multimedia content and combine it with high-level features provided by the wisdom of the crowd. To this end, we first performed an offine performance assessment by implementing a pure content-based recommender system with three different versions of the same algorithm, respectively based on (i) conventional movie attributes, (ii) mise-en-scène features, and (iii) a hybrid method that interleaves recommendations based on movie attributes and mise-en-scène features. In a second study, we designed an empirical study involving 100 subjects and collected data regarding the quality perceived by the users. Results from both studies show that the introduction of mise-en-scène features in conjunction with traditional movie attributes improves both offine and online quality of recommendations.