Recommendation Systems¶
Goal: Identify item(s) most relevant to a user
Types¶
Focus | Free from New User Cold Start Problem | Free from New Item Cold Start Problem | Personalized | Contextual (eg: time of day) | Scalable | Rank | |
---|---|---|---|---|---|---|---|
Popularity-based | Top items | ✅ | ❌ | ❌ | ✅ | ✅ | ✅ |
Classifier | Predict if each item would be liked or not | ✅ | ✅ | ✅ | ❌ | ❌ | |
Content-based filtering | Recommend similar items | ❌ | ❌ | ✅ | ✅ | ⚠️ | ✅ |
User-based | Recommend items that similar users liked | ||||||
Collaborative Item-based filtering | Recommend similar items, given co-occurence of purchases | ❌ | ❌ | ✅ | ✅ | ⚠️ | ✅ |
Collaborative User-based filtering | Recommend items that similar users liked, given purchase history | ❌ | ❌ | ✅ | ✅ | ⚠️ | ✅ |
Matrix Factorization/ Model-based collaborative filtering | Perform collaborative filtering on a low-dimensional space Split original sparse matrix into constituent dense - learnt embedding space for user matrix - learnt embedding space for item matrix | ❌ | ❌ | ✅ | ✅ |