LaNA 2023 Linking Study Data

Data analysis
  • IRT item calibration using the open-source MIRT package (R statistical programming language); multiple-group IRT models for LaNA items; fixed item parameter calibration for TIMSS 2019 and PIRLS 2021 linking items.
  • Principal component analysis (PCA) on context variables to reduce dimensionality; principal components account for 90% of background variance retained per country.
  • Latent regression population modeling and plausible value generation using ETS MGROUP software; 5 plausible values drawn per student per subject (mathematics and reading) using a two-dimensional model.
  • Scale transformation onto TIMSS 2019 and PIRLS 2021 reporting metrics.
  • Sampling weights calculated by the IEA Hamburg Sampling Unit.
  • Context scale construction using the Partial Credit Model (PCM; ConQuest 2.0); scale regions created using the Latent Class Analysis for cut scores (LCA-CS) method.
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Secondary analysis
  • Secondary analyses should use the IEA IDB (International Database) Analyzer software to correctly apply sampling weights and account for plausible values when computing statistics.
  • Plausible values are not individual test scores; they should only be used for group-level analyses. Analyses using only one plausible value will underestimate variance; all five PVs must be used.
  • The LaNA 2023 User Guide and accompanying documentation provide detailed guidance for secondary analyses.
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Types of data files
  • International database containing student achievement data and contextual data for all six participating countries
  • Student-level data files (linking questionnaire responses, achievement item scores, plausible values, sampling weights, derived variables)
  • School-level data files (school context questionnaire)
  • Additionally: codebooks and data documentation
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Format(s) of data files
  • R
  • SPSS
  • SAS
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Item release policy

Items from the LaNA assessment were not publicly released, as they were retained for use in future assessment cycles. However, a set of representative sample items ("illustrative exemplars") is available upon request for demonstration purposes.

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Major data-related sources
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