what do we do about duplicate student/school pairs in the same term?

[almartin82]

@chrishaid I think we allow this, because a student might be dual enrolled across schools (certainly someone is, somewhere) but it's definitely a little goofy.

here's an example from our sample data:

> mapviz$roster[mapviz$roster$studentid == 'F08000033', ]
             termname                            districtname                      schoolname
538    Fall 2013-2014 NWEA Partner Support Reporting District    St. Helens Elementary School
1125 Spring 2012-2013 NWEA Partner Support Reporting District    St. Helens Elementary School
1839 Spring 2013-2014 NWEA Partner Support Reporting District    St. Helens Elementary School
1899 Spring 2013-2014 NWEA Partner Support Reporting District Three Sisters Elementary School
2524 Winter 2013-2014 NWEA Partner Support Reporting District    St. Helens Elementary School
     studentlastname studentfirstname studentmi studentid studentdateofbirth
538            Smith          Ledonna         A F08000033         11/14/2007
1125           Smith          Ledonna         A F08000033         11/14/2007
1839           Smith          Ledonna         A F08000033         11/14/2007
1899           Smith          Ledonna         A F08000033         11/14/2007
2524           Smith          Ledonna         A F08000033         11/14/2007
     studentethnicgroup studentgender grade fallwinterspring map_year_academic
538  Hispanic or Latino             F     1             Fall              2013
1125 Hispanic or Latino             F     0           Spring              2012
1839 Hispanic or Latino             F     1           Spring              2013
1899 Hispanic or Latino             F     1           Spring              2013
2524 Hispanic or Latino             F     1           Winter              2013
     studentlastfirst studentfirstlast
538    Smith, Ledonna    Ledonna Smith
1125   Smith, Ledonna    Ledonna Smith
1839   Smith, Ledonna    Ledonna Smith
1899   Smith, Ledonna    Ledonna Smith
2524   Smith, Ledonna    Ledonna Smith