Amostra de filmagem e análise da pragmática na síndrome de Down***** Filmed sample size and pragmatic analysis in Down syndrome

Background: assessing language development is a complex task that requires practical and theoretical knowledge about the investigated issues. It is also important to take into account data gathering and analysis methodology, in order to achieve consistent and reliable results that mirror the subject's reality. Aim: considering the purpose of obtaining the maximum data in minimum time, without jeopardizing their quality and effectiveness, our aim is to identify the better sample's size and moment of videotaped interaction to study the pragmatic abilities of children with Down syndrome. Method: the communicative profile of 25 children with Down syndrome aged between 2 and 7 years were determined as proposed by Fernandes (2004). Data obtained through samples of 15 and 30 minutes were analyzed and compared. The situation analyzed provided interaction between the child and a speech-and language-therapist in play situations. To determine the statistical significance of data the tests Friedman, Wilcoxon and confidence interval were applied with a significance level of 0.05 (5%). Conclusion: there were no significant differences related to the obtained samples with different videotaped duration for pragmatic analysis of the communication of children with Down syndrome.