GEOCODES.DAT is supplemental data to be used with the 
ELS:2002 Restricted ECB (E2R).  A layout file (GEOCODES.LAY) is
provided for the location of variables in the GEOCODES.DAT file and
a SAS program (GEOCODES.SAS) and an SPSS program (GEOCODES.SPS) are
provided for user convenience and to provide the formats of the 
categorical variables.

Descriptions of the contents of the file are described below.

STU_ID - ID used to merged with the E2R Student.pri file.  There are
         15525 unique IDs in the file and the file is sorted by 
         the STU_ID.

Address and census 2000 geographic codes --
A ZIP code was linked to every student regardless of whether the 
student's residential address was located.  Multiple address sources
and address dispositions existed.  Addresses were ranked in order
to assign the best address to the student by 1) BY Parent 
questionnaire 2) BY Student questionnaire and 3) School provided
student address.  The best source was sent to be geographically
matched.  If an exact match did not occur, the next address was sent.
In the event that no address matched exactly, partial information with
at least a valid ZIP code was used to match the address at a higher
geographic level (i.e., the State and County code).  If the residence
could not be located, the ZIP code of a surrogate address 
(i.e., PO Box, Rural Route, BY School) was assigned.  This allowed
100% of the sample to have at least the FIPS State and County codes.

   BYGZIPCD - ZIP code of address used for geocode matching.  
   BYGSTATE - FIPS State code of address used for geocode matching
   BYGCNTY  - FIPS County code of address used for geocode matching
   BYGTRACT - Tract code of address used for geocode matching
   BYGBLOCK - Block code of address used for geocode matching


Claritas Prizm NE codes --
Once the geographic codes were assigned to the students, the full address
(or ZIP code only, in the case of partial or surrogate addresses) was sent
to Claritas to be matched for Prizm NE codes.  Whenever Claritas was not 
able to match all addresses at the ZIP+4 level, they would provide
the most common Prizm NE code associated with that geographic
location.  More information about Prizm NE codes can be obtained from
http://www.claritas.com

   BYGPRIZM - Prizm NE code

Status codes --
   BYGSRCE  - Displays whether the source was the student address or
              in the event that the address could not be located, the
              school address
   BYGMATCH - Status of matching the address for geocoding and the 
              level in which the geocodes are matched
   BYGPSTAT - Status of matching the address for Prizm NE codes and
              the level in which the Prizm NE code is assigned