The three cold starts
Collaborative methods need history, but cold start breaks that. There are three flavors: a new user with no clicks, a new item with no interactions, and a new system with almost no data at all.
Strategies for new items
- Lean on content features like text, category, or image embeddings so a fresh item lands near similar known items.
- Use a hybrid model that blends content with collaborative signal as interactions trickle in.
Strategies for new users
- Ask a few onboarding questions or show a quick preference picker.
- Fall back to popularity or demographic priors until signal accumulates.
- Use contextual cues such as device, time, and location.
Bandits to learn fast
- Treat early exposure as exploration, showing varied items to learn taste quickly.
- A bandit balances exploring new options against exploiting what already works.
Trade off
- Too much exploration annoys users, too little leaves cold items invisible forever.
Key idea
Cold start is solved by leaning on content features, popularity priors, and context for fresh entities, then using exploration to gather interactions that hand off to collaborative models.