comparing "mean length of utterance" and "mean length of five phrasal utterances" between 2-to-5 year-old farsi-speaking children

background: since most clinical treatments of persian children’s language impairments are based on either the therapist, clinicians’ experiences (mostly), or english language norms (sometimes), comparing two minor indices of speech quality, namely “mean length of utterance” (mlu) and “mean length of five phrasal utterances” (mlfpu) between different age groups of children, would be unequivocally efficient to help diagnose and treat farsi-speaking children with language impairments. methods: to compare the two mentioned indices of 2 to 5-year-old normal farsi-speaking children, the speech samples of 500 children were scrutinized by elicitation, transcription, and statistically analyzing their language samples. results: the net results prove that as the children’s ages grow from 2 to 5, the two mentioned indices increase and extend as well. conclusion: the influence of chronological age on the indices varies, regarding the type of language samples. hence, the analysis of speech quality indices in assessment of children’s language ability has to be performed based on the language sampling methods.