About the presenter: David Ward, PhD is a Lecturer and Director of the Speech Research Laboratory at the University of Reading, UK. He is both a practicing speech language therapist and a person who clutters, and currently Chairs the International Cluttering Association's academic and research committees. His personal research interests cluster around both theoretical and clinical issues in both stuttering and cluttering, and he has presented papers, published journal articles, book chapters and recently a textbook in these areas.

You can post Questions/comments about defining cluttering to Kathy Scaler Scott and Yvonne van Zaalen-op't Hof before May 4, 2010.

Cluttering: A Spectrum Perspective

by David Ward
from United Kingdom

The issue of how cluttering might best be defined has been the subject of ongoing debate for over 45 years, since Weiss (1964) contentiously argued that the disorder could be seen as just one characteristic of what he termed a central language imbalance. My position, first outlined in Ward (2006), is that there are advantages in taking a spectrum approach to the definition of cluttering; that is, cluttering-like symptoms can appear at a point on a spectrum between more normal and less normal examples. At one end there is a speech language output which would readily be regarded as "cluttering ", but further along the spectrum lie behaviours which might be regarded as cluttering-like, but where there is less certainty about these warranting a diagnosis of cluttering. I recently summarize my position, thus:

The term cluttering spectrum behavior can be defined as a speech/language output that is disrupted in a manner consistent with cluttering, but where there is a) insufficient severity; b) insufficient breadth of difficulties; or c) both, to warrant a diagnosis of cluttering. (Ward, in press)

The notion of a cluttering spectrum can also be applied to scenarios where it is not clear whether the symptoms are regarded as cluttering, or relate to another disorder with which cluttering might co-exist (Ward, 2006; 2007; in press).

An alternative viewpoint to definition, most recently refined in St Louis & Schulte (in press) is the lowest common denominator (LCD) approach. The purpose here is to capture the most important points of the disorder, whilst doing away with other features which are considered to exist outside the core (LCD) definition. It is further argued that an LCD perspective provides the best platform from which to advance our understanding of the disorder, and that without a more narrow definition, research into cluttering will lack objectivity, and may ultimately be pointless.

Relating to the first point, I have no argument with the features that St Louis places at the centre of cluttering, and it would be hugely surprising if any clinician failed to identify someone clearly displaying the LCD behaviours as anything but cluttering. But I am not convinced that there is any primacy in including these core characteristics over and above language features. Many clinicians grew up with the notion that language could play a significant part in cluttering (Dalton & Hardcastle, 1989; Weiss, 1964). There is now emerging scientific evidence of a language component in cluttering (Van Zaalen, Ward, Nederveen, Lameris, Wijnen, & Dejonckere, 2009; Van Zaalen, Wijnen & Dejonckere, in press) to add to the anecdotal "evidence " of clinicians dating back to Weiss (1964). Put another way, there is probably a decent level of agreement as to what cluttering is, but more disagreement as to what it is not.

A further problem for definition lies in the nature of the speech (and/or language) disruptions that characterise the disorder. Stuttering has proved difficult to define succinctly, yet the difficulties in objectively capturing the behavioural elements of the disorder are few in comparison with those implied in a cluttering diagnosis. An uncontrolled two-second block, even if it occurs only once within a two thousand word speech sample, is still stuttering. We cannot apply the same rubric to cluttering, where the very nature of the behaviours means we must use subjective terms when describing both the characteristics and the frequency of behaviours. Whilst ultimately, an LCD definition is desirable, it is difficult to see how this approach, alone, would be able to deal with these issues.

Problematic though definition remains, such difficulties with objectively measuring the scope and severity of symptoms need not be cause for despair. Autism provides one example of a disorder that may be readily identifiable at its core, but where further along the Autism spectrum, the boundaries between disorder and normal variability can become blurred. Migraine, too, has core symptoms, which like cluttering vary in scope and severity, and may be difficult to qualify and quantify objectively. This difficulty is likely to be exacerbated when the point of overlap of symptoms with those of other disorders is not well understood. Despite these problems, both Autism and Migraine continue to be researched scientifically.

Finally, as I argue in a recent paper (Ward, in press), it is perfectly possible for both LCD and spectrum perspectives to co-exist. We can recognize core symptoms (though we may for the moment continue to debate what exactly might be considered as "core "). Equally, for reasons stated above, we should consider both severity and scope of behaviours as factors which potentially can determine an appearance along a spectrum, rather than within a core definition.


Dalton, P. and Hardcastle, W. (1989) Disorders of fluency and their effects on communication, London: Elsevier, North-Holland.

St Louis, K.O. and Schulte, K. (in press) Defining cluttering: the lowest common denominator. In D. Ward and K. Scaler Scott, (Eds.), Cluttering: a handbook of research, intervention and education. East Sussex; Psychology Press.

Van Zaalen Y., Ward, D., Nederveen, A.J., Lameris, J.L., Wijnen, F. and Dejonckere, P. (2009) Cluttering and stuttering: different disorders and differing functional neurologies; Presentation at fifth International Fluency Association congress, Rio de Janeiro.

Van Zaalen, Y; Wijnen, F. and Dejonckere, P. (In press) Cluttering and learning disabilities. In D. Ward, and K. Scaler Scott, (Eds.), Cluttering: a handbook of research, intervention and education. East Sussex; Psychology Press

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

Ward, D. (2007) Stuttering and normal nonfluency: cluttering spectrum behaviour as a functional descriptor of abnormal fluency. Paper presented at the 1st International congress on cluttering. Razlog, Bulgaria, June, 2007.

Ward, D. (in press) Scope and constraint in the diagnosis of cluttering: combining two perspectives. In D. Ward, and K. Scaler Scott, (Eds.), Cluttering: a handbook of research, intervention and education. East Sussex; Psychology Press

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

You can post Questions/comments about defining cluttering to Kathy Scaler Scott and Yvonne van Zaalen-op't Hof before May 4, 2010.
SUBMITTED: March 8, 2010
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