ICCS 2009 Technical Report - IEA

Although all students enrolled in the sampled classes were part of the target population, ICCSrecognized that some student exclusions were necessary because of a physical or intellectualdisability or in cases where there were non-native-language speakers. Accordingly, the samplingguidelines allowed the exclusion of students with any of several disabilities. (For moreinformation on sampling procedures, see Chapter 6.) Countries were required to track andaccount for all excluded students and were cautioned that excluding more than five percent ofstudents would require annotation of their results in the ICCS reports. It was important thatthe conditions under which countries excluded students was carefully documented, because thedefinition of disability could vary from country to country.Linking students to classes and schools and teachers to schoolsThe international project staff established a system to assign hierarchical identification codes(IDs). These uniquely identified and allowed tracking of the sampled schools, teachers, andclasses. Table 8.1 represents the hierarchical identification system codes.Table 8.1: Hierarchical identification (ID) systemUnit ID Components ID Structure Numeric ExampleSchool School CCCC 1001Class School + Class within School CCCCKK 100101Student School + Class within School + Student within Class CCCCKKSS 10010101Teacher School + Teacher within School CCCCTT 100101Every sampled student was assigned an eight-digit identification number unique within eachcountry. Each number consisted of the four-digit number identifying the school, followed by atwo-digit number identifying the class within the school, and a two-digit number identifyingthe student within the class.Each sampled target-grade teacher of the selected school (i.e., those teachers listed on theteacher tracking form) was assigned a teacher identification number consisting of the four-digitschool number followed by a two-digit teacher number unique within the school.Preparing the test instruments for data collectionAs outlined in Chapter 5, NRCs were required to document any national adaptations to theassessment instruments on the national adaptation forms (NAFs) and to submit these to the ISCfor review and further discussion. The NAFs, provided in Microsoft Excel format, included allquestion-related texts (e.g., question stem, response options, answer categories, etc.) as well asvariable names.The ISC provided countries with all the necessary instrument production files, including fonts,style guides, graphic files, and explicit instructions on how to use the materials in order toproduce good-quality test instruments. (The instructions were given in Unit 1 of the ICCSsurvey operations procedures.) The national centers managed the translation of the assessmentinstruments from English into the language(s) used in their countries and later submitted themfor independent verification (see Chapter 5 of this report for details).Following translation verification and revision of the instruments, national center staffassembled the final assessment instruments. The ISC undertook a final layout verification of theinstruments, and national centers were asked to revise them, where necessary, prior to printing.ICCS SURVEY OPERATIONS PROCEDURES93