topic Re: The concept of "Lift" in Sequential Association Rule in SAS Data Science

The concept of "Lift" in Sequential Association Rule

SeanKwon — Wed, 06 Apr 2016 08:28:06 GMT

Hello,

I did Sequential Association Rules with SAS E-Miner.

Then, I could not find "Lift" in the result.

I realized that "lift" cannot be defined in Sequential Association Rules, but I don't know why.

Is there anyone who explain why the concept of "Lift" cannot be defined in Sequential Association Rules?

Re: The concept of "Lift" in Sequential Association Rule

LinusH — Wed, 06 Apr 2016 10:42:26 GMT

Moved to Mining forum - a more appropriate forum for this question.

Re: The concept of "Lift" in Sequential Association Rule

WendyCzika — Wed, 06 Apr 2016 13:45:00 GMT

This is from the SAS Enterprise Miner Reference Help, hope this answers your question:

Lift is traditionally not calculated for Sequence Analysis. In an Association analysis, the lift is the proportion of time that the right-hand side (RHS) occurs, given that the left-hand-side (LHS) has occurred. This computation is straightforward when there is only one LHS and one RHS, which is the case in Association. The computation becomes much more complex when you have a sequence that has more than one step.

In the sequence,

A -> B -> C -> D

, are you looking at the subset of events where A -> B -> C occurred and then D occurred? Or, are you interested in looking at A -> Band then later C -> D? There is not a unique way to create a lift. Therefore, lift is not calculated.

Re: The concept of "Lift" in Sequential Association Rule

SeanKwon — Thu, 07 Apr 2016 04:17:34 GMT

Thank you for your quick response~!

I'm sorry, but frankly speaking, I cannot understand it well.

I already know that lift is not calculated in sequential association rules.

But, I want to know why.

As you know, in Association Rules, Lift is defined as "Confidence A / P(A)".

For example, in the sequence

A → B → C → D

I want to know Lift of B→C.

we can calculate Confidence of B→C, and P(B→C).

Thus, I think that we should be able to calculate Lift of B.

Why is not this fomular right?

Re: The concept of "Lift" in Sequential Association Rule

WendyCzika — Thu, 07 Apr 2016 13:22:14 GMT

This paper has some code that might be helpful: http://www2.sas.com/proceedings/forum2007/132-2007.pdf