In Stuttering: An Integrated Approach to Its Nature and Treatment (1998), Barry Guitar presents a model of how stuttering develops and why it should be treated differently at different stages. It is a hierarchical model of five levels, the first level being normal disfluency. The next four levels- borderline stuttering, beginning stuttering, intermediate stuttering and advanced stuttering- reflect the progressive stages of the development of the disorder.

The following table clearly defines each of the five developmental levels. Within each level the characteristics are divided into four subgroups: core behaviors, secondary behaviors, feelings and attitudes, and underlying processes. The last subgroup describes factors that explain why the symptoms progress from level to level. Children who stutter will not always fit neatly into a single category; rather, you may see some behaviors that reflect one level and other behaviors that reflect another.

Level of Dysfluency Core Behaviors Secondary Behaviors Feelings and Attitudes Underlying Processes
Normal Disfluency Disfluency less than 10% of the time 1 to 2 repetitions per instance Slow, even behaviors None None Developing
Speech/ motor control
Borderline Stuttering Frequency of disfluency increases to more than 10%. Repetitions increase to more than 2 per instance. Repetitions remain loose and relaxed.  


Little awareness

Little concern

Same as above
Beginning Stuttering Tense, abrupt multiple part-word repetitions.

Tense prolongations

Pitch rise

Articulatory posturing with increased tension

Difficulty initiating airflow and voicing

Escape behaviors


Early fear



Response to awareness
Intermediate Stuttering Blocks

Repetitions and prolongations continue

Avoidance of words and situations



Shame Embarrassment

Classically conditioned tension

Classically conditioned fear

Avoidance conditioning

Advanced Stuttering Blocks

Stoppage of air flow

Tremors from increased duration of blocks

Avoidance of words and situations

Scanning (i.e., thinking ahead to identify potentially difficult or feared words or sounds)




Strong negative feelings about self

Stronger conditioning
Developed sense of self
as a stutterer

Source: Adapted with permission from information in Guitar, B., Stuttering: An Integrated Approach to Its Nature and Treatment. Copyright 1998 by Waverly.

Normal Disfluency: For the child to be diagnosed as having normal disfluency, all characteristics of this level must be met. A child who shows any of the characteristics of more advanced levels should be considered borderline or above. Frequency of disfluency must be less than ten per one hundred words. The disfluencies consist of multisyllabic and phrase repetitions, revisions and interjections. Repetitions are slow and even, and two or fewer occur per repetitive instance. In general, the child’s disfluencies appear relatively relaxed and the child hardly seems aware of them.

Borderline Stuttering: This child exhibits more than two disfluencies per one hundred words. This level is characterized by part-word repetitions and single-syllable whole-word repetitions. More than two repetitions may occur per instance, but the disfluencies at this level remain loose and relaxed.

Beginning Stuttering: The important features at this level are the presence of tension and “hurry” in the stuttering, as well as the emergence of prolongations. The repetitions may be rapid and abrupt, and pitch and loudness rise may be observed during repetitions and prolongations. The child may display facial tension and difficulty initiating airflow or voicing. At the beginning stuttering level, the child will show signs of awareness or the stuttering and may be quite frustrated by it. The child may begin using escape behaviors- such as head nods or eye blinks- in an attempt to terminate the stuttering. The child’s developing negative response to the awareness of stuttering is the factor that leads to continued progression of the disorder.

Intermediate Stuttering: This child will have all of the preceding characteristics plus avoidance behaviors. Conditioning to the experience of stuttering occurs at this level; intolerance of the stuttering and avoidance of words and situations begin to appear. Feelings of shame and fear also emerge at this level.

Advanced Stuttering: The child who falls in this category is typically fourteen years or older and requires a generally adult-oriented treatment approach.

An important point is that a child may progress through these levels without it necessarily being apparent, especially to untrained listeners, that the stuttering is getting worse.