Objective: To find reliability of parental or caregiver’s report and testing of the Thai Speech and Language Test for Children Aged 0-4 Years Old.
Material and Method: Five investigators assessed speech and language abilities from video both contexts: parental or caregivers’ report and test forms of Thai Speech and Language Test for Children Aged 0-4 Years Old. Twenty-five normal and 30 children with delayed development or risk for delayed speech and language skills were assessed at age intervals of 3, 6, 9, 12, 15, 18, 24, 30, 36 and 48 months.
Results: Reliability of parental or caregivers’ testing and reporting was at a moderate level (0.41-0.60). Inter-rater reliability among investigators was excellent (0.86-1.00).
Conclusion: The parental or caregivers’ report form of the Thai Speech and Language test for Children aged 0-4 years old was an indicator for success at a moderate level. Trained professionals could use both forms of this test as reliable tools at an excellent level.

Keywords: Test, Speech and language, Reliability