Table of Contents

- 1 How do you calculate minimum support and minimum confidence?
- 2 How do you set support and confidence in association rule mining?
- 3 How do you calculate support and confidence?
- 4 How do you calculate the confidence measure for an association rule?
- 5 How do you interpret support confidence and lift?
- 6 What is minimum confidence?
- 7 What is the maximum value of Min support and confidence?
- 8 What is the confidence of an association rule?

## How do you calculate minimum support and minimum confidence?

The Minimum Support Count would be count of transactions, so it would be 60\% of the total number of transactions. If the number of transactions is 5, your minimum support count would be 5*60/100 = 3.

### How do you set support and confidence in association rule mining?

Association rule mining finds interesting associations and relationships among large sets of data items….

- Support(s) –
- Support = (X+Y) total –
- Confidence(c) –
- Conf(X=>Y) = Supp(X Y) Supp(X) –
- Lift(l) –
- Lift(X=>Y) = Conf(X=>Y) Supp(Y) –

**What do we refer to by minimum support and minimum confidence in association rule mining?**

Association rule generation is usually split up into two separate steps: A minimum support threshold is applied to find all frequent itemsets in a database. A minimum confidence constraint is applied to these frequent itemsets in order to form rules.

**What is support and confidence in association rule?**

Support is an indication of how frequently the items appear in the data. Confidence indicates the number of times the if-then statements are found true. With that, association rules are typically created from rules well-represented in data.

## How do you calculate support and confidence?

We can get the rule confidence by dividing the support count of ab and by dividing the support count of a, because a appears in transaction 100,200,300,400 and the support count is 4, and the support count for ab is 3. Therefore rule confidence for a→b is 3/4 = 0.75.

### How do you calculate the confidence measure for an association rule?

If the association rule is (2,5) -> (3), than is X = (2,5) and Y = (3). The confidence of an association rule is the support of (X U Y) divided by the support of X. Therefore, the confidence of the association rule is in this case the support of (2,5,3) divided by the support of (2,5).

**What is support and confidence with example?**

Support represents the popularity of that product of all the product transactions. Confidence can be interpreted as the likelihood of purchasing both the products A and B. Confidence is calculated as the number of transactions that include both A and B divided by the number of transactions includes only product A.

**What is minimum support threshold?**

A minimum support threshold can be applied to get all thefrequent itemsets in a dataset. A minimum confidence constraint can be applied to these frequent itemsets if you want to form rules.

## How do you interpret support confidence and lift?

For rule 1:

- Support says that 67\% of customers purchased milk and cheese.
- Confidence is that 100\% of the customers that bought milk also bought cheese.
- Lift represents the 28\% increase in expectation that someone will buy cheese, when we know that they bought milk. This is the conditional probability.

### What is minimum confidence?

The confidence of an association rule is a percentage value that shows how frequently the rule head occurs among all the groups containing the rule body. The confidence value indicates how reliable this rule is. You set minimum confidence as part of defining mining settings.

**How do you get confidence and support?**

The support of a rule is the number of transactions that contains X∪Y. The confidence of a rule is the number of transactions that contains X∪Y divided by the number of transactions that contain X.

**How do you calculate support confidence?**

support(A ⇒ B [ s, c ]) = p(A ∪ B) Confidence: denotes the percentage of transactions containing A which contain also B. It is an estimation of conditioned probability . confidence(A ⇒ B [ s, c ]) = p(B|A) = sup(A,B)/sup(A).

## What is the maximum value of Min support and confidence?

Its all depend upon the data that you are trying to analyze.There is no any fixed value of min support and confidence.If there is more data than you can set min support to 10\% and then gradually increase it until you find more intereseting rules that you are interested.If your data is less that set min support and confidence to 50\%.

### What is the confidence of an association rule?

The confidence of an association rule is a percentage value that shows how frequently the rule head occurs among all the groups containing the rule body. The confidence value indicates how reliable this rule is. The higher the value, the more likely the head items occur in a group if it is known that all body items are contained in that group.

**What percentage of minimap should be used for confidence?**

For the confidence, it is a little bit easier because it represents the confidence that you want in the rules. So usually, I use something like 60 \%. But it also depends on the data. Besides, if you don’t want to use the minsup parameters you can use a top-k mining algorithm.

**What are the appropriate values for support and confidence?**

I would suggest to start with values 0.05 for support and 0.80 for confidence. But I agree that you should understand what exactly they represent in order to be able to define them appropriately. For a rule A => B (where A, B non empty sets) Support (A ⇒ B): s = P(A, B) Confidence (A ⇒ B): c = P(B | A) Lift (A ⇒ B): L = c/P(B)