Complicated Multi-Row Formula--Don't even know where to start with the syntax

[gene_denny]

I honestly have no clue how to even start this one.  Take the snapshot of my current Results pane as reference.

I would like to add a column named 'Cohort' that is populated with a simple Yes/No.  The logic is if the value of schoolID is equal for both Winter 2017 and Winter 2018 for each personID, then a Yes is written.  Else, it is a No.

For personID=929, the schoolID for each of these rows is not equal, so a No is rendered in the final column of Rows 28 and 29.  The same is true for personID=934 because there is no row for Winter 2018.  For personID=1031, the schoolID field matches for both Winter 2017 and Winter 2018 and, thus, a Yes would be rendered in the final column of Rows 31 and 32.

I don't know how to reference a particular field value based on another field value.

Any gurus want to lend me some of their intelligence?

[patrick_digan · Accepted solution]

I think you can use a multi-row tool or a summarize tool to accomplish this. I've provided both in the attached. If you're situation turns out to be more complicated, then the logic may need to be tweaked.

[gene_denny]

Owe you one.

The Multi-Row formula syntax was what I was after, although both solutions you provided look workable.  Sincerely appreciate the help!

[gene_denny]

I tried to apply the same logic to a similar, but separate, workflow but now it doesn't work properly and I am unable to determine the difference.  Here is the data set Results, without the final column populating.

I am still using the Multi-Row tool as 

So, what am I missing?

[gene_denny]

Disregard, I see my mistake.  Needed to change the Values for Rows that don't Exist to Null