According to Ambrose and Yairi, the purpose of this report is to provide such a reference. To develop, refine, and answer theoretical questions regarding the characteristics of stuttering in the early stages of the disorder and to provide a basis for the clinical needs of differential diagnosis of stuttering from normal disfluency, their goal was to obtain data from the sample size, that represented population variability in very early stuttering in preschool children. Ambrose and Yairi have questions, in addition to providing normative data for dysfluency types for early stuttering and normal dysfluencies, regarding possible gender and age differences with the preschool range. In this study there are two groups, the experimental group and the control group. The experimental group consisted of 90 preschool children who stuttered, while the control group consisted of 54 normally fluent children. The independent variables were the number of stuttered syllables per word read or spoken. This is a variable not manipulated in the study. The independent variable manipulated was the test score to determine the severity of the fluency disorder. The dependent manipulated variable was the authors, speech therapists, and parents in the case study. They were able to influence the test by controlling some aspects of it. Subjects in the experimental group were referred to the University of Illinois Stuttering Research Project to evaluate the resourcefulness of their parents, doctors, nurses, speech specialists, and day care staff. All children in the stuttering (experimental) group met the following multiple objective and subjective criteria: (a) aged 60 months or younger, (b) considered by their parents to have a stuttering problem, (c) considered by the two authors ( certified speech pathologists with extensive experience with fluency disorders) as having a stuttering problem, (d) severity of stuttering rated by parents as greater than 1 on an 8-point scale (0 = normal; 1 = borderline; 2 = mild; 7 = very severe), (e) severity index greater than 1 assigned by the two authors, (f) exhibition of at least three stuttering-like disfluencies (SLD, or word repetitions of parts and single syllables and blocks/prolongations of sounds) per 100 syllables, (g) history of stuttering no longer than 6 months, and (h) no obvious neurological disorders or abnormalities. Subjects in the normal fluency (controlled) group were (a) 60 months of age or younger, (b) reported by their parents as having no history of stuttering, (c) considered by the researchers