Prepare a clean interaction table
Collect user-item interactions and item metadata, deduplicate records and split by time or users to avoid leakage.
Promote diverse recommendations. Balance relevance and variety.
Diversity-aware recommendation aims to increase the variety of items presented to users while preserving relevance. Practical issues include defining diversity objectives (catalog coverage, category balance, novelty), measuring trade-offs with relevance, and enforcing business rules during ranking.
Learning concept · Not a validated service
Diversity-aware recommendation aims to increase the variety of items presented to users while preserving relevance. Practical issues include defining diversity objectives (catalog coverage, category balance, novelty), measuring trade-offs with relevance, and enforcing business rules during ranking.
A proposed application: an e-commerce browse feed that mixes relevant popular items with under-exposed categories to help users discover new products while retaining relevance. Any production build should include human review for business constraints before deployment.
Collect user-item interactions and item metadata, deduplicate records and split by time or users to avoid leakage.
Implement a simple collaborative filter or similarity-based scorer as a reproducible baseline for relevance before adding diversity rules.
Define a diversity objective (category coverage, dissimilarity, novelty) and apply reranking or determinantal point process methods to balance relevance and variety.
Measure Precision@K, NDCG and coverage or catalog exposure metrics, and inspect failure cases where diversity harms user satisfaction.
The supplied starter builds a tiny synthetic user-item rating table, computes a user-by-item pivot, calculates cosine similarity between users, finds the single most similar neighbour for a target user, and recommends the neighbour's highest-rated unseen items. It implements a basic user-based collaborative filter on a small hard-coded dataset and prints the top candidate 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,
)
target_user = "user_1"
neighbor = user_similarity[target_user].drop(target_user).idxmax()
unseen_items = matrix.loc[target_user][matrix.loc[target_user] == 0].index
scores = matrix.loc[neighbor, unseen_items].sort_values(ascending=False)The code implements a basic user-based collaborative filter but contains no diversity-aware objective, reranking, coverage constraint or item metadata. It also uses a tiny synthetic dataset of six users/items, so results do not reflect real catalogue scale or diversity challenges.
A proposed extension: replace the synthetic ratings with a real interaction log and item metadata, compute per-item categories, and apply a reranking stage (for example MMR or DPP) to trade off relevance and category coverage for each recommendation slate.
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.