Pearson Correlation 76543210 Item 2 Item 3 Item 4 Item 5 Items User a - User B -UserC Pearson correlation User AbC B11-19 Pearson Correlation 0 1 2 3 4 5 6 7 Item 1 Item 2 Item 3 Item 4 Item 5 Items Rating User A User B User C Pearson Correlation A B C A 1 1 -1 B 1 1 -1 C -1 -1 1 User User