Z-Score Workflow Problem

Question

Hi:

I am working with a number of population variables for a Census level Block Group analysis and I am struggling with the Z-Score calculation.

From my table of rows by Block Group, I dragged the Summarize Tool down and ran the Average (Mean) and Std. Deviation for each variable (not grouped by anything), but I don't know where to go from this point in order to convert them to a Z-Score. I have all my formula tools set up but I don't know what the approach to get the two Summarize tools reconnected to the original data table for calculation. The screenshot essentially show the gap in my workflow. I knew I was doing something wrong when my Z-Score were not providing any negative values.

Can someone please help point me in the right direction?

Thanks,
Donny

Z-ScoreScreenShot.JPG

RafaelH · Accepted Answer

From your Summarize tools I would bring in two Append Fields tools to append the calculated sigmas and means, your target inputs, to each source observation. You will need to configure both Append Fields tools to "Allow All Appends" in the drop down selection below to allow for more than 16 records to pass through.

After that, I would use a Formula Tool to create the (source - mean) / sigma column for each source field, to get your scaled fields.

Hope this helps.

MarqueeCrew · Accepted Answer

@RafaelH,

While @ddavis216 was writing his reply, I was creating a macro to calculate the Z-Score.  I did not write the table lookup, but thought that I'd give you a finished macro that will compute the score on your behalf.

Cheers,

Mark