For nearly 20 years, I have argued that cluttering should be defined in terms of its "lowest common denominator" (LCD) (e.g., St. Louis, 1992; St. Louis, Raphael, Myers, & Bakker, 2003; St. Louis, Myers, Bakker, & Raphael, 2007). (note: The first person is used here since all of my coauthors have not entirely agreed that an LCD definition is the best approach to defining cluttering.) In a recent chapter (St. Louis & Schulte, in press), I refined the previous LCD definitions as follows:

"Cluttering is a fluency disorder wherein segments of conversation in the speaker's native language typically are perceived as too fast overall, too irregular, or both. The segments of rapid and/or irregular speech rate must further be accompanied by one or more of the following: (a) excessive "normal" disfluencies; (b) excessive collapsing or deletion of syllables; and/or (c) abnormal pauses, syllable stress, or speech rhythm."

The following explanations were provided to assist in interpretation and application of the St. Louis & Schulte definition to diagnostic situations:

• Cluttering must occur in naturalistic conversation in one's native language to rule out limited ability in a non-native language or reading problems.
• The cluttering need not occur consistently; a few isolated examples are sufficient for a diagnosis.
• A speaker's mastered and habitual non-native language is acceptable for a diagnosis in multilingual living environments.
• Syllable rates may not exceed those of normal speakers, but irregular rates will sound "jerky" or "spurty."
• Disfluencies are most likely those that are typically not observed in people who stutter but in normal speakers, but more frequently.
• Collapsing syllables includes--but is not limited to--excessive shortening, "telescoping," or "over-coarticulating" syllables, especially in multisyllabic words.

Regardless of whether or not the foregoing speculations about initial suspicion are true, it can be argued that an LCD definition of cluttering provides the best option for advancing empirical knowledge about the nature, diagnosis, and treatment of cluttering (Scaler Scott & St. Louis, 2009; St. Louis & Schulte, in press). There is little argument that cluttering coexists with numerous communication and other disorders, e.g., disorders of phonology, language, stuttering, central auditory processes, attention deficit and/or hyperactivity, learning, apraxia, and even the autism spectrum (e.g., St. Louis et al., 2007; Ward, 2006). The position advanced here is that until or unless clinicians and researchers agree on what cluttering is--and is not--the field will continue on the course of viewing the disorder in terms of the examples clinicians have seen most often (e.g., Weiss, 1964), and by default, often generalizing more about unique symptom complexes of coexisting disorders than the common condition of cluttering that accompanies all of them. The result of not eliminating such contradictions and confusions in the definition will be that the literature on cluttering will continue to be relegated to well-intentioned but inconsequential speculation at best and to pseudo-science at worst.

References

Scaler Scott, K. & St. Louis, K. O. (2009, July). A perspective on improving evidence and practice in cluttering. Perspectives on Fluency and Fluency Disorders, 19(2), 46-51.

St. Louis, K. O. (1992). On defining cluttering. In F. L. Myers & K. O. St. Louis (Eds.). Cluttering: A clinical perspective (pp. 37-53). Kibworth, Great Britain: Far Communications. (Reissued in 1996 by Singular, San Diego, CA.)

St. Louis, K. O., Myers, F. L., Bakker, K. & Raphael, L. J. (2007). Understanding and treating cluttering. In Conture, E. & Curlee, R. (Ed.), Stuttering and related disorders of fluency (pp. 297-325). New York: Thieme.

St. Louis, K. O., Raphael, L. J., Myers, F. L., & Bakker, K. (2003, November). Cluttering updated. The Asha Leader, 8-21, 4-5 & 20-23.

St. Louis, K. O., & Schulte, K. (in press). Defining cluttering: The lowest common denominator. In D. Ward & K. S. Scott (Eds.) Cluttering: Research, intervention, education. East Sussex, UK: Psychology Press.

Ward, D. (2006). Stuttering and cluttering: Frameworks for understanding and treatment. East Sussex, UK: Psychology Press.

Weiss, D. (1964). Cluttering. Englewood Cliffs, NJ: Prentice Hall.