MB Analysis - Lift

[Daniel_He]

Hello together,

I am trying to do a market basket analysis.

Therefore, I used the MB Rule- & MB Inspect tool. The workflows works just fine.

However, the "Lift" KPI is calculated incorrectly.

From testing with a small sample size I think I figured out that Alteryx gives out the "Support" of the LHS item/item bundle as the "Lift" of the whole LHS & RHS-rule (see red marker).

If I calculate "Lift" manually as [Support productbundle AB] / ([support product A] * [support product B]), I do get different results than Alteryx. E.g. for Egg -> Salt, Lift should be 2. However, Alteryx gives out 0,5 as the corresponding Lift (just the same as the support value..., see yellow marker).

I am desperatly trying to find my/the error. Can someone help me? Find my simple testing workflow and the input-Excel attached.

Thanks in advance!

Best regards,

Daniel

[robbinrv]

Hi Daniel, bit late to the party here but just noticed the same issue on our workflows here.
On version 2020.4 I get the correct expected lifts but when opened in 2021.2 I get the wrong Lift (just the LHS support).
Dummy workflow attached as well.
Feels like something is wrong in the way the report/data is produced/output.

Created a support ticket, let's see if they can help

[shiqi]

Hi all, I am encountering the same issue on v2021.3. Has a fix been found?

[vishnuakshay]

Hi All, I am having same issue on 2021.3 version.can any one help me with this.?

[jzamora]

In 2021.3 Ateryx is returning the Coverage metric instead of the Lift metric. This is a very disappointing error.

This function in R (using arules package) 

DATAFRAME(apriori(yourdata, parameter = list(minlen=2, supp=0.002, conf=0.05)))

returns a column with support, confidence, coverage, lift and count