Recommender Systems — Overview

Course: Recommender Systems — 2025/2026 Programme: MSc Artificial Intelligence, UvA (IRLab) Coordinators: Maarten de Rijke, Yubao Tang Lecturers: Maarten de Rijke, Yubao Tang, Clara Rus, Xiaoyu Zhang, Yuyue Zhao, Kidist Amde Mekonnen, Dominykas Seputis Lectures: June 1–5, 2026 Format: A short lecture series followed by a course project (no textbook).

Reading

  • No prescribed textbook. Lectures draw in part on the Recommender Systems Handbook (Ricci, Rokach, Shapira & Kantor, 2011) and on recent papers cited per lecture.
  • Each lecture note below is written to be exam-substitute complete — the slides are the only durable source, so the notes reproduce them in full.

Assessment

To fill in

This course is project-based. Add the concrete project brief, deliverables, deadlines, and grading weights here once available — administrative detail is owned by you, not auto-generated.

ComponentWeightNotes
Course Projectdetails TBD by Stanisław

Lecture Schedule

TopicLecturer(s)DateNotes
L1Course Overview & Introductionde Rijke, TangJun 1RS-L01 - Course Overview & Introduction
L2Evaluation — Beyond AccuracyRusJun 2RS-L02 - Evaluation Beyond Accuracy
L3aSequential Recommender SystemsZhangJun 4RS-L03a - Sequential Recommendation Models
L3bFrom LLMs to LRMs (Generative Rec)ZhaoJun 4RS-L03b - From LLMs to LRMs
L4Generative RecommendationMekonnen, SeputisJun 5RS-L04 - Generative Recommendation

Concept Index

Key concepts covered in this course (see the Concepts/ folder).

Foundations: Recommender System · Collaborative Filtering · Neighborhood-based Collaborative Filtering · Content-Based Recommendation · Hybrid Recommendation · Matrix Factorization · Neural Collaborative Filtering · Implicit and Explicit Feedback · User-Item Interaction Matrix · Cold Start Problem · Data Sparsity · Top-N Recommendation · Negative Sampling · Bayesian Personalized Ranking (BPR)

Accuracy Evaluation: Precision at K · Recall · NDCG · MRR · MAP · Hit Rate

Beyond-Accuracy: Beyond-Accuracy Metrics · Diversity · Novelty · Serendipity · Catalog Coverage · Maximal Marginal Relevance (MMR) · Popularity Bias · Long-Tail Distribution · Filter Bubble

Fairness & Bias: Fairness in Recommendation · Position Bias · Inverse Propensity Weighting · Algorithmic Fairness · Exposure Fairness

Evaluation Methodology: B Testing · Online and Offline Evaluation

Sequential Recommendation: Sequential Recommendation · Session-based Recommendation · Markov Chain · Factorized Personalized Markov Chains (FPMC) · GRU4Rec · SASRec · BERT4Rec · Recurrent Neural Network (RNN) · Gated Recurrent Unit (GRU) · Self-Attention · Next-Item Prediction · Contrastive Learning · Transformers

LLMs & Large Recommendation Models: Generative Recommendation · LLM-based Recommendation · Large Language Models (LLM) · Large Recommendation Models (LRM) · In-Context Learning · Supervised Fine-Tuning (SFT) · Direct Preference Optimization (DPO) · LoRA · Reinforcement Learning from Human Feedback · Cross-Domain Recommendation · Scaling Laws · HSTU · OneRec

Item Tokenization & Generative Retrieval: Item Tokenization · Semantic IDs · Atomic Item IDs · RQ-VAE · TIGER · P5 · Constrained Decoding · Beam Search · Autoregressive Generation · Diffusion Models · Generative Retrieval · DSI · Approximate Nearest Neighbor · Product Quantization