UNIQUE and COUNTIF for exact duplicates
Exact duplicates — rows where every character matches — are the easy case. Two functions catch them: UNIQUE and COUNTIF.
UNIQUE to extract the distinct list
In a new sheet tab (or to the right of your data), write:
=UNIQUE(working!M2:M)
This spills a column of every distinct normalized name. If your roster has 80 rows but UNIQUE returns 73 names, you have 7 duplicate pairs to investigate.
COUNTIF to flag duplicates inline
Back in the main working sheet, add a Dup_Count column. In cell N2:
=COUNTIF(M:M, M2)
Drag down. Every row now shows how many times that normalized name appears in the column. Any row with a count greater than 1 is part of a duplicate set.
You can then filter the roster to rows where Dup_Count > 1 and review them by hand.
Why review by hand
Two people named Maria Vasquez might be two different workers. The normalizer cannot tell. Always review duplicate-flagged rows manually before deleting anything.
Action: Mark this page complete when you have finished the activity above.