Prepare item metadata & constraints
Collect and clean item attributes (category, tags, availability) and formalise business rules or user constraints that the recommender must respect.
Apply knowledge-based recommendation. Combine rules and metadata.
Knowledge-based recommendation combines explicit item metadata, business rules and user constraints to suggest items when collaborative signals are weak or safety/diversity rules must apply. Good practice includes defining item attributes, encoding business rules, testing rule coverage and measuring ranking metrics plus business KPIs.
Learning concept · Not a validated service
Knowledge-based recommendation combines explicit item metadata, business rules and user constraints to suggest items when collaborative signals are weak or safety/diversity rules must apply. Good practice includes defining item attributes, encoding business rules, testing rule coverage and measuring ranking metrics plus business KPIs.
A proposed application: a product-catalog recommender that enforces business constraints (age-appropriate, in-stock, brand exclusions) and uses item attributes to match user needs when historical behaviour is limited.
Collect and clean item attributes (category, tags, availability) and formalise business rules or user constraints that the recommender must respect.
Map item attributes to matching rules or similarity heuristics (for example attribute overlap or rule-based scoring) rather than relying only on past ratings.
Layer rule-based scores with collaborative or popularity signals as fallbacks and implement deterministic safety checks before exposing recommendations.
Measure Precision@K, NDCG and rule-violation rates; inspect failure cases where rules suppress good items or allow unsafe suggestions.
The supplied starter implements a tiny user-based collaborative-filtering baseline: it pivots three users' ratings into a user-item matrix, computes cosine similarity between users, finds the most similar user to a target, and recommends that neighbour's highest-rated unseen items.
matrix = ratings.pivot_table(index="user", columns="item", values="rating").fillna(0)
user_similarity = pd.DataFrame(
cosine_similarity(matrix),
index=matrix.index,
columns=matrix.index,
)The code is not knowledge-based: it uses no item metadata, no business rules and no attribute-driven scoring. It also runs on a toy six-user/item rating set, so it does not validate production behaviour or rule coverage.
Proposed extension: augment the baseline with an item-attribute store and a rules engine that scores items by attribute match and enforces constraints such as in-stock, age or brand rules; combine those scores with collaborative fallbacks.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.