Investigating the differential item functioning of a PIRLS Literacy 2016 text across three languages

This study forms part of a larger study (Roux, 2020), which looked at the equivalence of a literary text across English, Afrikaans, and isiZulu from the Progress in International Reading Literacy Study (PIRLS). PIRLS is a large-scale reading comprehension assessment that assesses Grade 4 students' reading literacy achievement. PIRLS Literacy 2016 results for South African Grade 4 students indicated poor performance in reading comprehension, with approximately eight out of 10 Grade 4 students who could not read for meaning. Descriptive statistics led to the Rasch analysis, which was conducted using the South African PIRLS Literacy 2016 data. Even though the Rasch analysis indicated differential item functioning across the three languages for this specific passage, there was no universal discrimination against one particular language. By conducting differential item functioning, it was possible to determine whether the selected text had metric equivalence, in other words, whether the test questions were of similar difficulty across languages.