7.3.1 Design 7. 3.2 Results and discussio 7. 4 Summary 133 8 Motivating Contributions of Users 8.1 Introduction 8.2 Research Questions 137 Experimental Design 8.3.1 Experimental Groups 8.3.2 The Experiment 8.3.3 Hypotheses 140 8.3.4 Post-Survey 8.4 Methods 8. 4.2 Movie list 8.4.3 Item value 8.5 Results and discussion 148 8.6 Summary 150 v Epilogue 152 153 9. 1 Future research directions 9.1.1 Attacks on Recommender Systems 9.1.2 Early Evaluations by Influencers 9.1.3 Recommendation Accuracy 9. 1.4 Interface Issues 9.1.5 Diffusion of Influence 9. 1.6 Other Collaborative Filtering Algorithms 160 Bibliography 161 Reproduced with permission of the copyright owner. Further reproduction prohibited without permissionReproduced with permission of the copyright owner. Further reproduction prohibited without permission