Similarity calculation

Pearson correlation coefficient

Usually choose to use: Pearson correlation coefficient.

Neighbor’s Choice

User-based collaborative filtering

Problems to be solved in user-based collaborative filtering

Issues of user-based collaborative filtering:

Basic solutions:

Is user-based collaborative filtering uncommon?

Item-based collaborative filtering:

Advantages of item-based collaborative filtering:

User cold start problem:

Cold start problems for items:

Cryptic meaning model:

Cryptic meaning model solution:

Negative sample selection of cryptic meaning model:

Parameter selection of cryptic model:

Collaborative filtering VS cryptic meaning

Evaluation criteria: