Stuttering Severity Instrument (SSI-4)

The Stuttering Severity Instrument–Fourth Edition (SSI–4) is a reliable and valid norm-referenced stuttering assessment that can be used for both clinical and research purposes. It measures stuttering severity in both children and adults in the four areas of speech behavior:

 

Frequency is expressed in percentage syllables stuttered and converted to scale scores of 2–18. Duration is timed to the nearest one tenth of a second and converted to scale scores of 2–18. The four types of Physical Concomitants are converted to scale scores of 0–20. The SSI-4 can also be used in conjunction with the Stuttering Prediction Instruments for Young Children (SPI).

 

The SSI–4 was normed on a sample of 72 preschool-aged children, 139 school-aged children, and 60 adults. It has four components, each of which is used to assess and monitor stuttering severity in both children and adults for clinical and research use: (1) Examiner’s Manual and Picture Plates, (2) Test Record and Frequency Computation Forms, (3) Subjective Stuttering Scales, and (4) Computerized Scoring of Stuttering Severity (Software Version 2.0).