The Stuttering Severity Instrument–Fourth Edition (SSI-4) measures stuttering severity in children and adults at the conversation level. Disfluent behaviors are measured in 3 major areas which include the frequency of occurrence, the duration of the 3 longest stuttering moments, and the occurrence of physical concomitants (secondary behaviors). A total score is established from the combination of the 3 major areas. The total score is compared to peers with disfluent behaviors at the preschool level (5 and under), school age level (6-16) or adult level (17 and up). Percentile and Severity equivalents of the total overall score are then established based on conversion tables for peer groups of similar chronological age.
Frequency of syllables spoken: %
Average Duration: seconds
Physical Concomitants (Secondary Behaviors):
Movements of the Extremities:
Percentile range for preschool aged children: