Example Which movie would sammy watch next? Ratings 1--5 Titles Starship Sleepless Trooper in Seattle MI-2 Matrix Titanic (R (R) Sammy Beatrice Dylan g Mathew 44423 Gum-Fat A333445 333345 1344? 454? Basil If we just use the average of other users who voted on these movies then we get Matrix 3: Titanic 1474=3.5 Recommend titanic But is this reasonable?4 Example ◼ Which movie would Sammy watch next? ◼ Ratings 1--5 • If we just use the average of other users who voted on these movies, then we get •Matrix= 3; Titanic= 14/4=3.5 •Recommend Titanic! •But, is this reasonable? Starship Trooper (A) Sleepless in Seattle (R) MI-2 (A) Matrix (A) Titanic (R) Sammy 3 4 3 ? ? Beatrice 3 4 3 1 1 Dylan 3 4 3 3 4 Mathew 4 2 3 4 5 Gum-Fat 4 3 4 4 4 Basil 5 1 5 ? ? Titles Users