93 items
Popularity-Based Baseline Recommenders
Slides / VideoPopularity Bias and Filter Bubbles
Slides / VideoDiversity, Novelty, and Serendipity
Slides / VideoRanking vs Rating Prediction
Slides / VideoEvaluation Metrics for Recommenders
Slides / VideoSparsity and Scalability Challenges
Slides / VideoThe Cold Start Problem
Slides / VideoHybrid Recommender Systems
Slides / VideoMatrix Factorization and Latent Factors
Slides / VideoSimilarity Measures: Cosine and Pearson
Slides / VideoExplicit vs Implicit Feedback
Slides / VideoThe User-Item Interaction Matrix
Slides / VideoUser-Based vs Item-Based Filtering
Slides / VideoWhat a Recommender System Is
Slides / VideoCollaborative Filtering Overview
Slides / VideoContent-Based Filtering Basics
Slides / VideoReal-World Applications of Recommender Systems
Slides / VideoPrecision@K Denominator
Code QuizBuilding a CSR Sparse Matrix
Code QuizAverage Precision Rank Index
Code QuizDCG Log Discount
Code QuizRecall@K Denominator
Code QuizCatalog Coverage Denominator
Code QuizWeighted Hybrid Score Blend
Code QuizBuilding an Implicit Feedback Matrix
Code QuizPopularity-Based Baselines
QuizWhat a Recommender System Is
QuizThe Cold-Start Problem
QuizEvaluating Recommenders (Precision@K, Recall@K)
QuizHybrid Recommender Systems
QuizNeighborhood vs Model-Based Methods
QuizItem-Based Collaborative Filtering
QuizCollaborative Filtering Overview
QuizRanking Metrics (NDCG, MAP, MRR)
QuizExplicit vs Implicit Feedback
QuizOffline vs Online Evaluation
QuizLatent Factors in Recommendations
QuizUser-Based Collaborative Filtering
QuizDiversity, Novelty, and Serendipity
QuizDeep Learning for Recommendations
QuizScalability in Recommenders
QuizUser-Item Interaction Matrix
QuizFilter Bubbles and Feedback Loops
QuizCandidate Generation and Ranking Stages
QuizData Sparsity Challenge
QuizRanking vs Rating Prediction
QuizContent-Based Filtering
QuizMatrix Factorization for Recommendations
QuizContext-Aware Recommendations
QuizKnowledge-Based Recommendations
QuizSimilarity Measures (Cosine, Pearson)
QuizBPR Ranking Loss Direction
Code QuizMissing vs Zero Ratings in Average
Code QuizFiltering Already-Seen Items
Code QuizTop-N Recommendation Ranking
Code QuizBuilding a User Profile
Code QuizBias Terms in MF Prediction
Code QuizRegularization in Matrix Factorization
Code QuizPopularity-Based Baseline
Code QuizCold-Start Fallback Logic
Code QuizContent-Based Cosine Similarity
Code QuizSGD Update for Latent Factors
Code QuizMatrix Factorization Prediction
Code QuizWeighted Rating Aggregation
Code QuizMean-Centering Ratings
Code QuizSelecting the K Nearest Neighbors
Code QuizItem-Based CF Prediction
Code QuizUser-Based CF Prediction
Code QuizBuilding the User-Item Matrix
Code QuizReal-World Applications of Recommenders
FlashcardContext-Aware and Session-Based Recommendations
FlashcardPopularity-Based / Baseline Recommenders
FlashcardPrecision@K and Recall@K
FlashcardFilter Bubbles and Feedback Loops
FlashcardNeighborhood-Based Methods
FlashcardScalability Challenges in Recommenders
FlashcardRanking Metrics: NDCG, MAP, MRR
FlashcardDeep Learning-Based Recommenders
FlashcardCandidate Generation vs Ranking
FlashcardDiversity, Novelty, and Serendipity
FlashcardSimilarity Measures for Recommendations
FlashcardCold Start Problem
FlashcardMatrix Factorization
FlashcardData Sparsity in Recommenders
FlashcardLatent Factors and Embeddings
FlashcardUser-Item Interaction Matrix
FlashcardHybrid Recommender Systems
FlashcardItem-Based Collaborative Filtering
FlashcardCollaborative Filtering Overview
FlashcardWhat is a Recommender System
FlashcardExplicit vs Implicit Feedback
FlashcardUser-Based Collaborative Filtering
FlashcardContent-Based Filtering
FlashcardSelecting the K Nearest Neighbors
Find why this KNN neighbor selection picks the wrong users.
def get_neighbors(sims, k):
# sims: dict of user_id -> similarity score
sorted_users = sorted(sims.items(), key=lambda x: x[1])
return sorted_users[:k]What is the bug in this neighborhood selection?