Purpose: Disfluencies can be classified as stuttering-like disfluencies (SLDs) or typical disfluencies (TDs). Dividing TDs further, stalls (fillers and repetitions) are thought to be prospective, occurring due to planning glitches, and revisions (word and phrase revisions, word fragments) are thought to be retrospective, occurring when a speaker corrects language produced in error. In the first study assessing stalls, revisions, and SLDs in matched groups of children who stutter (CWS) and children who do not stutter (CWNS), we hypothesized that SLDs and stalls would increase with utterance length and grammaticality but not with a child's expressive language level. We expected revisions to be associated with a child having more advanced language but not with utterance length or grammaticality. We hypothesized that SLDs and stalls (thought to be planning-related) would tend to precede grammatical errors.
Method: We analyzed 15,782 utterances from 32 preschool-age CWS and 32 matched CWNS to assess these predictions.
Results: Stalls and revisions increased in ungrammatical and longer utterances and with the child's language level. SLDs increased in ungrammatical and longer utterances, but not with overall language level. SLDs and stalls tended to occur before grammatical errors.
Conclusions: Results suggest that both stalls and revisions are more likely to occur in utterances that are harder to plan (those that are ungrammatical and/or longer) and that, as children's language develops, so do the skills they need to produce both stalls and revisions. We discuss clinical implications of the finding that ungrammatical utterances are more likely to be stuttered.