Normalization of the Non-word Repetition Test in Farsi-speaking Children

The Phonological Working Memory (PWM) plays an essential role in many cognitive functions, such as language acquisition. Impaired PWM can result in learning disability. Therefore, the existence of a standard test for the assessment of this ability, especially in children, is vital. Evidence suggests that the Non-Word Repetition (NWR) task is a good representative of PWM competence. This study aimed to normalize the NWR test for Farsi-speaking children. Also, we aimed at assessing the external reliability of this test.

The NWR test, including main and parallel tests, was performed on 455 typically-developed children in five age groups ranging from four to nine years old. We attempted to have an almost equal number of participants in different socio-economic status groups and sexes.

We found a remarkable relationship between the main and parallel test results (P≤0.001). There was a direct relationship between age and NWR performance in the main (P≤0.001) and the parallel (P≤0.001) tests. Also, boys obtained better total scores in the main (P=0.002) and the parallel (P≤0.001) tests.

The test has high external reliability. The results showed non-word repetition ability increased with age. The reported standard scores and normative data can be used for screening and assessing PWM among children.