Recommender systems 23 human 13 Humans 12 Collaborative filtering 11 Recommender system 11 Behavioral research 8 female 7 male 7 recommender system 7 Personalized recommendation 6 Recommendation system 6 adult 6 Article 5 Deep learning 5 Recommendation 5 Recommendation algorithms 5 Female 4 Knowledge graphs 4 Male 4 Students 4 controlled study 4 recommendation 4 recommendations 4 recommended drug dose 4 Adult 3 COVID-19 3 Collaborative filtering algorithms 3 Decision making 3 E-learning 3 Feature extraction 3