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
MNX_SE
PCT
Contains the standard error of MNX computed using the JRR method for computing the
standard error.
Contains the weighted percent of people in the group for the classification variable listed
last, within the specific combination of the categories defined by the groups defined
initially. In our example, we would obtain the percent of boys and girls, within each
combination of country and grade.
PCT_SE
Contains the standard error of PCT computed using the JRR method for computing the
standard error.
The file resulting from using this macro can then be printed using a SAS procedure of
choice. An example call to this macro, and a subset of the resulting file is presented in Figure
9.8. In this example the macro will compute the percent of boys and girls, by grade and by
country, and their mean achievement in mathematics. The listing presented in Figure 9.8 is
interpreted in the following way. The first line shows the results for the students with
IDCNTRY=36 (Australia), in IDGRADER=1 (Seventh grade), and who had ITSEX=1 (Girls).
It is estimated that there are 123649 seventh-grade girls in Australia, their mean mathematics
score is 500, with a standard error of 4.3. We can also tell from this line of data that it is
estimated that 52 percent of the seventh graders in Australia are girls, and the standard error
of this percent is 2.3. The second line shows the same information, but for the seventh-grade
boys (ITSEX=2). It is estimated that there are 114646 seventh grade boys in Australia, their
mean mathematics score is 495, with a standard error of 5.2. We can also tell from this line of
data that it is estimated that 48 percent of the seventh graders in Australia are boys, and the
standard error of this percent is 2.3.
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