Associationg Rules/ Mining is this association rule strong

Question

I have a problem. I can't not solve this exerciese. What is the best way to solve this exerciese? What are the approaches for this kind of exerciese?

The following table summarizes transactions in a supermarket where customers bought tomatoes and/or mozzarella cheese or neither.

We study the association "mozzarella => tomatoes" (with the idea that many people like to eat mozzarella with tomatoes (plus fresh basil plus olive oil - yum!)) and assume a minimum support threshold of 25% and a minimum confidence threshold of 50%. Is this association rule strong?

Answer 1

Market Basket Analysis is a technique which identifies the strength of association between pairs of products purchased together and identify patterns of co-occurrence. A co-occurrence is when two or more things take place together.

Market Basket Analysis creates If-Then scenario rules, for example, if item A is purchased then item B is likely to be purchased. The rules are probabilistic in nature or, in other words, they are derived from the frequencies of co-occurrence in the observations. Frequency is the proportion of baskets that contain the items of interest. The rules can be used in pricing strategies, product placement, and various types of cross-selling strategies.

Here is the calculation :

Support({Moz}--{Tom} = Transaction containing both moz and tom / total number of transaction

  = 2000/ 5000  = 2/5 = 0.4

Confidence({Moz}--{Tom}) = Transaction containing both moz and tom / total number of transaction containing Moz
= 2000 / 2500 = 2/2.5 = 0.8

Lift({Moz}--{Tom}) = (Transaction containing both moz and tom / total number of transaction containing Moz ) / Fraction of transaction containing Y

= 0.8 / (3000/5000)

= 0.8/0.6 = 1.33

For your table this association mining rule is strong