I think your formula is undercounting your unduplicated headcount.  Unless you do not have any new students for the spring semester and no summer school the formula you use is not even close.  We take the census files for the four term (we have two summer sessions) and do an Unduplicate in Excel to get the total students who attended in the year.


Timothy Walsh Ed.D.

Immaculata University

Interim Director, Office of Institutional Research and Effectiveness

Villa Maria #213

PO Box 702, 1145 King Road, Immaculata, PA 19345

office (484) 323-3177

fax (484) 323-3901





From: Ana Landrón Arana [mailto:alandron@SanJuanCiudadPatria.com]
Sent: Friday, May 20, 2016 5:59 PM
To: Common Data Set
Subject: [cds] IPEDS unduplicated headcount


Greetings all:


I know it’s Friday and I should be home but…  How does your institution count IPEDS unduplicated headcount data for a given academic year? 


Our institution uses:  FA15 + WI16 (new, first time and transfer students) = unduplicated headcount. 


However, do you count the readmitted students who left on another academic year and returns on the academic year being reported? For example, if a student enrolled FA 13, left on December 2013, and returned WI 16, should that student be counted or not in the 2015-2016 unduplicated headcount?    Since this student was counted in FA-13, should he/she be left out of the headcount, even though he/she is enrolled for credits in the current reporting period?


The 2015-2016 glossary indicates that “unduplicated count is the sum of students enrolled for credit with each student counted only once during the reporting period, regardless of when the student enrolled. “   So, does “when the student enrolled” refer to the reporting period?


Thank you for your time.



Prof. Ana Inés Landrón Arana


Oficina de Planificación, Investigación

Institucional y Recursos Externos