Novelty (in Recommender Systems)#
How unfamiliar or unexpected recommended items are to the user.
Important
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What it is#
Novelty measures how new or unfamiliar a recommender’s suggestions are to a user — surfacing items they’re unlikely to have already seen rather than obvious mainstream hits. It is a beyond-accuracy objective: a technically accurate list of things the user already knows adds little value.
How it’s measured#
Novelty is usually tied to popularity — the less popular an item, the more novel — so metrics use average recommendation popularity (lower means more novel) or the self-information (the negative log of an item’s popularity). Recommending from the long tail raises novelty.
Why it matters#
Novelty drives discovery and helps monetize the long tail, but pushed too far it sacrifices relevance — nobody wants random items. The art is balancing the accuracy-novelty trade-off; combined with relevance and surprise, novelty becomes serendipity.
Theme: Recommender Systems · All terminology
Hint
Mind map — connected ideas
Diversity (in Recommender Systems) · Coverage · Intra-List Diversity (ILD) · Relevance in Recommender Systems · Hit Rate (HR) · Cosine Similarity of Item Features
Hint
More in Recommender Systems
Catalog Coverage · Cosine Similarity of Item Features · Diminishing Utility · Diversity (in Recommender Systems) · Dominating in Recommender Systems · Genre Overlap · Hit Rate (HR) · Intra-List Diversity (ILD) · Item Coverage · Jaccard index · Relevance in Recommender Systems · Self-Information of Popularity · User Coverage
See also
Source article Adapted (context, re-expressed) in our own words from: Novelty (in Recommender Systems) (insightful-data-lab.com).