Efficiency of picture description and storytelling methods in language sampling according to the mean length of utterance index

Due to limitation of standardized tests for Persian-speakers with language disorders، spontaneous language sampling collection is an important part of assessment of language protocol. Therefore، selection of a language sampling method، which will provide information of linguistic competence in a short time، is important. Therefore، in this study، we compared the language samples elicited with picture description and storytelling methods in order to determine the effectiveness of the two methods. In this study 30 first-grade elementary school girls were selected with simple sampling. To investigate picture description method، we used two illustrated stories with four pictures. Language samples were collected through storytelling by telling a famous children''s story. To determine the effectiveness of these two methods the two indices of duration of sampling and mean length of utterance (MLU) were compared. There was no significant difference between MLU in description and storytelling methods (p>0. 05). However، duration of sampling was shorter in the picture description method than the story telling method (p<0. 05). Findings show that، the two methods of picture description and storytelling have the same potential in language sampling. Since، picture description method can provide language samples with the same complexity in a shorter time than storytelling، it can be used as a beneficial method for clinical purposes.