Apriori Algorithm Method Let k=1 Generate frequent itemsets of length 1 Repeat until no new frequent itemsets are identified Generate length(k+1)candidate itemsets from length k frequent itemsets if their first k-1 items are identical o Prune candidate itemsets containing subsets of length k that are infrequent o Count the support of each candidate by scanning the DB Eliminate candidates that are infrequent, leaving only those that are frequent n Steinbach. Kumar Introduction to Data Mining 4/18/2004© Tan,Steinbach, Kumar Introduction to Data Mining 4/18/2004 ‹#› Apriori Algorithm Method: – Let k=1 – Generate frequent itemsets of length 1 – Repeat until no new frequent itemsets are identified ◆ Generate length (k+1) candidate itemsets from length k frequent itemsets if their first k-1 items are identical ◆ Prune candidate itemsets containing subsets of length k that are infrequent ◆ Count the support of each candidate by scanning the DB ◆ Eliminate candidates that are infrequent, leaving only those that are frequent