Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.

ECIR 2019 - Information Retrieval Models for Contact Recommendation in Social Networks

106 visualizaciones

Publicado el

Slides for our paper "Information Retrieval Models for Contact Recommendation in Social Networks" at the 41st European Conference on Information Retrieval (ECIR 2019, Cologne, Germany, 13-18 April 2019)

Publicado en: Tecnología
  • Sé el primero en comentar

  • Sé el primero en recomendar esto

ECIR 2019 - Information Retrieval Models for Contact Recommendation in Social Networks

  1. 1. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Javier Sanz-Cruzado and Pablo Castells @JavierSanzCruza, @pcastells Universidad Autónoma de Madrid http://ir.ii.uam.es Cologne, Germany, April 15th 2019
  2. 2. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Motivation Online Social networks:  Appeared at early 2000s  Most used web applications  New challenges for IR Social Recommendation Search Social IR Content Recommendation Contact Recommendation
  3. 3. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Item recomendation 4 4 2 2 4 1 4 4 3 4 3 ? 2 ? 1 4 ? 4 3 3 1 1 1 5 2 Users Items Rating matrix
  4. 4. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Contact recomendation ? - 1 1 - 2 1 ? - ? 1 3 - 1 4 - Users Users Rating matrix = adjacency matrix
  5. 5. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Contact recommendation approaches Machine Learning Specifical models Recommender systems Contact recommendation Information Retrieval¿ ? Adaptations
  6. 6. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Relation between tasks Contact recommendation Target user Candidate user Relevant link ? Relevant result Term DocumentQuery Target user Candidate item Neighbor user Relevant item ? Collaborative filteringIR task
  7. 7. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Relation between tasks IR task Collaborative filtering Contact recommendation Target user Candidate user Neighbor user Relevant link ? Relevant result Term DocumentQuery Target user Candidate item Neighbor user Relevant item
  8. 8. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Relation between tasks Contact recommendation Target user Candidate user Neighbor user Relevant link Und In
  9. 9. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 An example: BM25 Original formulation: 𝑓𝑞 𝑑 = 𝑡∈𝑑∩𝑞 𝑘 + 1 freq 𝑡, 𝑑 𝑘 1 − 𝑏 + 𝑏 𝑑 avg 𝑑′ 𝑑′ + freq 𝑡, 𝑑 RSJ 𝑡 𝑅𝑆𝐽 𝑤 = log 𝐷 − 𝐷𝑡 − 0.5 𝐷𝑡 − 0.5 Where  𝑑: document  𝑞: query  𝑡: term  𝐷: set of all documents  𝐷𝑡: documents containing 𝑡  freq 𝑡, 𝑑 : frequency of 𝑡 𝑖𝑛 𝑑  𝑑 : document 𝑑 length Γ 𝑑 𝑣 : candidate user Γ 𝑞 𝑢 : target user 𝑡: neighbor user 𝒰: all users Γinv 𝑑 𝑡 : 𝑣 containing 𝑡 in Γ 𝑑 𝑣 𝑤 𝑑 𝑡, 𝑣 : edge weight len𝑙 𝑣 = 𝑥∈Γ 𝑙 𝑣 𝑤 𝑙 𝑥, 𝑣
  10. 10. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 An example: BM25 Original formulation: 𝑓𝑢 𝑣 = 𝑡∈Γ 𝑞 𝑢 ∩Γ 𝑑 𝑣 𝑘 + 1 w 𝑑 𝑡, 𝑣 RSJ 𝑡 𝑘 1 − 𝑏 + 𝑏 ⋅ len𝑙 𝑣 avg 𝑣′ Γ𝑙 𝑣′ + w 𝑑 𝑡, 𝑣 𝑅𝑆𝐽 𝑡 = log 𝒰 − Γinv 𝑑 𝑡 + 0.5 Γinv 𝑑 𝑡 + 0.5 Where  𝑑: document  𝑞: query  𝑡: term  𝐷: set of all documents  𝐷𝑡: documents containing 𝑡  freq 𝑡, 𝑑 : frequency of 𝑡 𝑖𝑛 𝑑  𝑑 : document 𝑑 length Γ 𝑑 𝑣 : candidate user Γ 𝑞 𝑢 : target user 𝑡: neighbor user 𝒰: all users Γinv 𝑑 𝑡 : 𝑣 containing 𝑡 in Γ 𝑑 𝑣 w 𝑑 𝑡, 𝑣 : edge weight len𝑙 𝑣 = 𝑥∈Γ 𝑙 𝑣 w 𝑙 𝑥, 𝑣
  11. 11. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Experiments  Offline evaluation  Data extracted from Twitter (REST API)  Interaction graphs: 𝑢, 𝑣 ∈ 𝐸 ⟺ 𝑢 retweets, mentions 𝑣  Snowball sampling  Two samples: 1. 1 month: All tweets between 19th June and 19th July 2015 2. 200 tweets: 200 last tweets by each user before 2nd August 2015
  12. 12. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Evaluation methodology  Networks are split in training/test (temporal split) – 1 month: Interactions before July 12th / after July 12th – 200 tweets: Interactions in first 80% of tweets / remaining 20%  Recommendations applied over train data – Reciprocal links are not recommended  Evaluated using IR metrics on test: P@10, R@10, nDCG@10
  13. 13. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Algorithms  IR models – Vector space model (VSM) – BIR – BM25 – Query Likelihood (QL) - Jelinek-Mercer, Dirichlet and Laplace smoothing  General collaborative filtering – User-based / Item-based kNN – Implicit matrix factorization (iMF)  Specific approaches – Adamic-Adar – Most common neighbors (MCN) – Personalized PageRank – Jaccard similarity – Money  Sanity-check: Random and most popular
  14. 14. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Results (P@10) 1 month 200 tweets BM25 0.0691 0.0572 BIR 0.0675 0.0534 QLL 0.0609 0.0490 QLJM 0.0580 0.0492 QLD 0.0441 0.0482 VSM 0.0191 0.0268 Money 0.0772 0.0476 Adamic-Adar 0.0676 0.0532 MCN 0.0631 0.0501 PageRank Pers. 0.0598 0.0336 Jaccard 0.0226 0.0304 iMF 0.0834 0.0541 User-based kNN 0.0805 0.0479 Item-based kNN 0.0739 0.0360 Popularity 0.0255 0.0225 Random 0.0009 0.0003  IR models are effective – Probabilistic models among top 5 – BM25 best in “200 tweets” – VSM lowest performing IR model  Rest of algorithms: – Implicit MF is best. – Adamic-Adar and MCN are competitive. – Jaccard is not very competitive. – Rest seem very graph- dependent.
  15. 15. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Efficiency BM25 is much faster than MF
  16. 16. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Conclusions  IR models can be applied to contact recommendation  They provide an effective and efficient solution  Future work: – More IR models – Effects of sampling methods on accuracy – Beyond accuracy: Novelty, diversity and effects on the network
  17. 17. IRGIRGroup @UAM Information Retrieval Models for Contact Recommendation in Social Networks 41st European Conference on Information Retrieval (ECIR 2019) Cologne, Germany, 15 April 2019 Thank you for your attention! Questions?

×