The third step to compute association rules of Market Basket Analysis is to apply two threshold criteria: minimum support and minimum confidence. Thus, we set these two thresholds into cells, for example we set 40% minimum support and 80% minimum confidence.
Then we add one more column in the computation to include the rule if both percent support and confidence are above the thresholds. We can apply some conditional formatting to make it nice.
After that, we copy the first row of our rules to the rest of all possible rules. Figure below shows part of the result.
To see the rule clearly, we use filtering in MS Excel and we found out two rules with high support and confidence
If you download the MS Excel companion of this tutorial, you can play around with parameter minimum support and minimum confidence. After you change the parameter, you need to go to Data tab and Reapply the filter.
Different threshold value will produce broader or stricter rules. For example, if we set the minimum support to 25% and minimum confidence to 60% we can obtain 8 association rules as shown in the figure below.