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

D A T A C O L L E C T I O N P R O C E D U R E S C H A P T E R 4
Whenever possible, national data were retained by recoding to match as closely as possible the
international version of the items and/or by documenting minor deviations. NRCs were
contacted to resolve questions regarding the international comparability of revised items, and
no changes were made to the international data files without first informing the NRC and
receiving confirmation whenever possible. A summary of all available documentation for the
deleted or modified background questionnaire items in the international data files is provided
in Supplement 3. 1
1 This documentation was sent to all NRCs for review and verification prior to release of the international data files.
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