User Guide for the TIMSS International Database.pdf - TIMSS and ...

C H A P T E R 9 P E R F O R M I N G A N A L Y S E S
9.1 Contents of the CDs
There are two CDs that accompany this User Guide – one CD containing the Population 1
data and one containing the Population 2 data. Each CD has the following internal file
structure:
• A main directory identifying the population (POP 1 or POP 2).
• Within each main directory, there are five sub-directories.
DATA: Contains ASCII data files
PROGRAMS: Contains SPSS and SAS programs
CODEBOOK: Contains codebooks
ALMANACS: Contains data almanacs
TCMA: Contains Test–Curriculum Matching Analysis Data
The directory names within each CD and the file names follow the DOS naming convention:
file names with up to eight characters, followed by a three-character extension (as in
FILENAME.EXT). Files with the same names are related to each other, and the extension
identifies their function. The extensions used in the files contained in the CDs are indicated in
Table 9.1 below.
Table 9.1
Three-letter Extension Used to Identify the Files Contained in the CD
Extension Description
.SAS SAS Control File or program
.SPS SPSS Control File or program
.DAT ASCII data file
.LIS Almanac
.CDT Codebook in printout format
.CDF Codebook in machine readable format
The DATA sub-directory contains the TIMSS data files in ASCII format. The different data
file types that are in this directory are described in Chapter 7. Each of these files has two
corresponding control files in the PROGRAMS sub-directory, as shown in Table 7.14. One of
these two files reads the ASCII data and creates a SAS data set, the second one reads the
ASCII data and creates an SPSS system file. There are several other programs in this
directory. The other programs that can be found in this directory are the following:
JACK.SAS and JACK.SPS
Both of these are macro programs, one in SAS and one in SPSS, that can be used to
compute the weighted percent of students within defined groups, and their mean on a
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