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

D A T A B A S E F I L E S C H A P T E R 7
Not Applicable Response Codes (6, 96, 996,...)
The Not Applicable Response Codes are used only for the background questionnaire items in
which responses are dependent on a filter question. If a dependent question was “not applicable”
to a respondent because he/she answered a filter question negatively, the dependent question(s)
have been coded to "not applicable." Also, if a respondent was not meant to answer a variable
because of its logical relationship to other variables in the questionnaire design, these variables
also have been recoded to "not applicable.” The specific Not Applicable Code value given
depends on the number of valid codes available for each item in the same fashion as was
described above for the Omitted Response Codes.
Not Reached Item Codes (6, 96)
The Not Reached Item Codes are used only for cognitive items. Test items at the end of each test
booklet in each testing session which were left blank were considered "not reached" due to the
fact that the student did not complete the test. These responses are distinguished from the
"missing" responses, as they are handled differently during the item calibration process (see
Chapter 5). They are treated as incorrect responses, however, in computing achievement scores.
For the multiple-choice items, a Not Reached Item Code value of 6 is used. For the free-response
written or performance assessment items, a Not Reached Item Code value of 96 is used.
7.2.6 National Data Issues Affecting the Use of International Data Files
In some cases, resources were not available to resolve database issues for specific countries in
time for either the release of the international reports or the production of the international data
files. As a result, some international data are modified or not available for some countries. These
general database issues are documented below.
Australia
Bulgaria
Israel
Information made available after publication of the Population 1 international reports
required that the Population 1 sampling weights for Australia be recomputed. The
adjusted sampling weights are included in the International Database. As a consequence,
any computations using these new weights may be slightly different from those shown in
the international report tables for Population 1.
The student, teacher, and school background data submitted by Bulgaria were not deemed
internationally comparable and are thus not included in the International Database.
Due to the use of unapproved school sampling procedures for the performance
assessment, the performance assessment results for Israel in the international report are
based on unweighted data at both the fourth and eighth grades (Harmon et al., 1997).
Thus, the sampling weights have been set to 1 for all cases in the performance assessment
file for Israel.
T I M S S D A T A B A S E U S E R G U I D E 7 - 31