# Association rules and itemsets

Reading about association rules mining made me somehow confused. I am wondering if this is possible that in a transaction, an item occurs more than once? Considering the following database as a reference:

Transaction id  Items
t1     {1,4,1}
t2     {2}
t3     {1,2,1}
t4     {2,2}
t5     {1, 2, 3, 5}


• the distinction is due to the fact that , in my mind, buying 6 of a soft drink with something would have more weight compare to buying , say, 2 of the same soft drink with some other item. In other words, it would be more associated to the first item compare to the second item. does that make any sense? I hope it does. – lonesome Nov 8 '15 at 10:55