st: list duplicates but within subgroups

[Michael Costello <michaelavcostello@gmail.com>]

Folks,

I have a poorly coded dataset that was typed from several thousand
paper surveys.  Often a stack of surveys would be entered into the
computer and then later entered again because of poor record keeping.
Each survey has two variables of interest, school_code and id.
Neither is unique, but there should be only one of each id in each
school_code.  For example, I should not have two children at
school_code=10 who both have the same id number, yet there will be
students at every school who have id=1, 2, etc.

I'm trying to find a command that uses some kind of subgroup option
for a -duplicates list- command.  I've tried all the easy ones
("duplicates list id, by school", "duplicates list id, over school",
"duplicates list id, sepby(school_code)" ) all with no luck.  Does
anyone have any ideas of commands, macros, or websites that might help
me with this?  Thanks for your help.
--
Michael Costello
RTI International
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