Transaction data: a set of documents A text document data set, each document is treated as a“bag” of keywords doc 1 Student, Teach, School doc2 Student School docs Teach, School, City, Game doc Baseball, Basketball doc5 Basketball, Player, Spectator doc Baseball. Coach. Game, Team doc: Basketball, Team, City, Game7 Transaction data: a set of documents ◼ A text document data set. Each document is treated as a “bag” of keywords doc1: Student, Teach, School doc2: Student, School doc3: Teach, School, City, Game doc4: Baseball, Basketball doc5: Basketball, Player, Spectator doc6: Baseball, Coach, Game, Team doc7: Basketball, Team, City, Game