English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Within the educational context, students' assessment tests are routinelyvalidated through Item Response Theory (IRT) models which assumeunidimensionality and absence of Differential Item Functioning (DIF). In thispaper, we investigate if such assumptions hold for two national testsadministered in Italy to middle school students in June 2009: the Italian Testand the Mathematics Test. To this aim, we rely on an extended class ofmultidimensional latent class IRT models characterised by: (i) a two-parameterlogistic parameterisation for the conditional probability of a correctresponse, (ii) latent traits represented through a random vector with adiscrete distribution, and (iii) the inclusion of (uniform) DIF to account forstudents' gender and geographical area. A classification of the items intounidimensional groups is also proposed and represented by a dendrogram, whichis obtained from a hierarchical clustering algorithm. The results provideevidence for DIF effects for both Tests. Besides, the assumption ofunidimensionality is strongly rejected for the Italian Test, whereas it isreasonable for the Mathematics Test.

Joint Assessment of the Differential Item Functioning and Latent Trait Dimensionality of Students' National Tests