IELS 2025 OUTCOME MEASURES

Assessment domain(s)
  • Emergent literacy
  • Emergent numeracy
  • Executive function

  • Social and emotional skills

     

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Achievement and test scales
Scale Creation
  • The IELS scales for the 10 outcome domains were developed based on item response theory and population models using plausible values.
  • Each scale was constructed as theorized in the assessment framework.
    • However, analysis was undertaken where there was some evidence of more complex dimensionality.
    • The only case where a theoretically proposed dimension was separated into multiple dimensions as a result of the dimensionality analysis was empathy (emotion identification and emotion attribution).
  • Once scales were developed, the population model (IRT calibration model and latent regression model combined) was applied to draw five plausible values for each child (across each scale).
  • In order to generate plausible values for the ten domains of interest, multi-dimensional scaling of ten latent dimensions (domains) was conducted.

  • The multidimensional random coefficients multinomial logit model (MRCMLM) was used in two steps: national and international item calibrations, and national conditioning and production of plausible values.

     

List of Achievement Scales
  • Emergent literacy
  • Emergent numeracy
  • Inhibition
  • Mental flexibility
  • Working memory
  • Emotion identification
  • Emotion attribution
  • Prosocial behaviour
  • Disruptive behaviour
  • Trust
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Questionnaire and background scales
Scale Creation
  • Item dimensionality was first confirmed using structural equation modelling (SEM) based on the conceptual underpinning of the questions in the assessment framework and the identified structure from field test data.
  • The internal consistency of the proposed scales was then established.
    • Cronbach’s alpha was used to check internal consistency of each scaled index within the countries and to compare it between the countries.
    • The assessment of model fit was primarily conducted through reviews of the root mean square error of approximation (RMSEA), the comparative fit index (CFI), and the non-normed fit index (NNFI).
    • The IELS analyses relied on robust weighted least squares estimation (WLSMV) to estimate the confirmatory factor models.
  • IELS categorical items from the context questionnaires were scaled using IRT modelling (i.e., the one-parameter Rasch model) to derive estimates of each scale for each child.
  • Weighted likelihood estimates, in short, WLE (logits), for the latent dimensions were transformed to scales with an average of 0 and a standard deviation of 1 (with equally weighted samples).
  • A composite index reflecting socioeconomic background was derived nationally, using principal component analysis of three family background indicators
    • highest parental occupational status
    • highest educational level of parents (in years of education according to ISCED)
    • household income
  • Only scale indices are reported below.

 

List of Background Scales
  • Staff reports of child’s global development
  • Staff reports of child’s social and emotional skills
  • Staff reports of child’s cognitive and motor skills
  • SES index score (nationally standardized)
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Sources - Measures
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