- Goals: Recent and Fresh, Diverse and Relevant
- 2 Phase
    - Candidate generations
        - Co-visitation RecommendationCo-visitation Recommendation
 Customer who viewed this also viewed
 
 
 
 
 
 
 
 
 
 
 
 
 Related work
 
 [[The Youtube video recommendation system 2010]]
 
 There are other interesting work which is Fake Co-visitation Injection Attacks to... (association rule mining)
 
- Co-visitation RecommendationCo-visitation Recommendation
- Ranking
        - Variety of signals for relevance and diversity
 
 
- Candidate generations
        
- Evaluations
    - CTR (Click Through RateClick Through Rate
 Click-Through-Rate (CTR) is the number of clicks that the item receives divided by the number of times the item is shown.
 
 clicks / impressions = CTR
 
 
 If we have 5 clicks and 100 impressions, our ...)
- CVR — long CTR (only counting clicks that led to watches of a substantial fraction of the video) Adoption and Conversion RatesAdoption and Conversion Rates
 Adoption and Conversion Rates often require a domain- and application-specific definition.
 
 Supports
 
 [[The Youtube video recommendation system 2010]]
 
 Long CTR - only counting clicks t...
- Session length
- Time until first long watch
- Recommendation coverage (the fraction of logged in users with recommendations)
 
- CTR (Click Through RateClick Through Rate
Results
They run an experiment as follows.
Period: 21 days
Metrics: CTR (Click Through RateClick Through Rate
Click-Through-Rate (CTR) is the number of clicks that the item receives divided by the number of times the item is shown.
clicks / impressions = CTR
If we have 5 clicks and 100 impressions, our ...)
Variants:
- Most viewed - Most popular videos within 1 day
- Top Favorited - Most favorited videos
- Top Rated - Most rated (liked) videos
- Recommended - Co-visitation along with users behaviors
Results: CTR increased by 207% compared to most viewed.

Reference
James Davidson et al., “The YouTube video recommendation system,” in Proceedings of the fourth ACM conference on Recommender systems - RecSys ’10, Barcelona, Spain, 2010, p. 293. doi: 10.1145/1864708.1864770.
#recommender-system/videos #recommender-system