Matrix Conditional Formatting based on Field Measure not working

Hi BeaudryL 

I noticed that your [Standard_Deviation] was returning zero for every row.

Because I'm not very experienced with STDEVX.P(), I decided to check CHAT-GPT and found the following:

STDEVX.P expects a table with multiple values per group.

You're summarizing MENTORS[Clinician] in _MeansByClincian, but @Mean is only storing a single aggregated value per clinician.

This means _MeansByClincian has only one row per clinician, making STDEVX.P return zero (since standard deviation requires variation).

Fix: Calculate standard deviation at the response level, not at the aggregated mean level. Instead of summarizing means per clinician first, compute the standard deviation directly from MENTORS[Response.Value].

__SD CHAT-GPT = 
    CALCULATE(
        STDEVX.P( 
            MENTORS, 
            MENTORS[Response.Value]
        )
    )

This, at least, doesn't return zero for each line.  You'll have to do some checking.

Let me know if you have any questions.

(I'm not sure why it is wrapped in a CALCULATE, but I just copied it.)