What is the cold start problem?

Updated May 16, 2026

Short answer

Cold start occurs when there is insufficient data about users or items.

Deep explanation

New users or items have no interaction history, making collaborative filtering ineffective. Solutions include using content-based methods, popularity-based recommendations, or onboarding questionnaires.

Real-world example

New Netflix user seeing trending movies initially.

Common mistakes

  • Relying only on collaborative filtering.

Follow-up questions

  • Types of cold start?
  • How to solve it?

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