Statistical Power in Stuttering Research: A Tutorial

Jones, Mark; Gebski, Val; Onslow, Mark; Packman, Ann
April 2002
Journal of Speech, Language & Hearing Research;Apr2002, Vol. 45 Issue 2, p243
Academic Journal
The capacity to make reliable inductive statements about populations is critical for the advancement of scientific knowledge. An important contribution to that advancement of knowledge is determining that effects are either present or not present in populations. Statistical power is an important methodological qualification for any research that presents statistical results, and particularly so for research that presents null results. In this paper we describe the statistical concept of power, outline parameters of research that influence it, and demonstrate how it is calculated. With reference to selected published research, attention is drawn to the problems associated with a body of underpowered research, one being that population effects may go undetected. One way to prevent this problem is to calculate power a priori in planning research and include confidence intervals when presenting the results of research. However, it is difficult, if not impossible in many cases, to obtain high participant numbers for communication disorders of low prevalence such as stuttering. With this in mind, the paper concludes with an attempt to open discussion about ways to redress the problems associated with statistical power.


Related Articles

  • Words Fail Me. Whirty, Ryan // Indianapolis Monthly;May2003, Vol. 26 Issue 10, p90 

    Focuses on stuttering and problems faced by the author due to it. There are three million stutterers in the U.S., people for whom the simple act of talking is an often-humiliating, nerve-wracking experience. Stuttering is like other conditions that negatively affect normal, everyday human...

  • Brain Correlates of Stuttering and Syllable Production: Gender Comparison and Replication. Ingham, Roger J.; Fox, Peter T.; Ingham, Janis C.; Jinhu Xiong; Zamarripa, Frank; Hardies, L. Jean; Lancaster, Jack L. // Journal of Speech, Language & Hearing Research;Apr2004, Vol. 47 Issue 2, p321 

    This article reports a gender replication study of the P. T. Fox et al. (2000) performance correlation analysis of neural systems that distinguish between normal and stuttered speech in adult males. Positron-emission tomographic (PET) images of cerebral blood flow (CBF) were correlated with...

  • Wrestling with words. YEOMAN, BARRY // Psychology Today;Nov/Dec98, Vol. 31 Issue 6, p42 

    Provides information on stuttering syndrome in children. What the Goal of stutterers should be; Causes of stuttering; Various comments on the issue; Information on the American Psychiatric Association's `Diagnostic and Statistical Manual of Mental Disorders' (DSM-IV).

  • Understanding stuttering.  // Current Health 1;Sep98, Vol. 22 Issue 1, p29 

    Discusses the causes of stuttering. How to talk to people who stutter; List of the famous people who stuttered.

  • Commentary on 'A Theory of Neuropsycholinguistic Function in Stuttering'. Smith, Anne // Journal of Speech & Hearing Research;Aug92, Vol. 35 Issue 4, p805 

    Comments on a study which proposed a neuropsycholinguistic theory of stuttering. Definition of stuttering; Analysis on the absence of citations to experimental work; Assessment on the theory.

  • Long-Term Follow-up of Self-Modeling as an Intervention for Stuttering. Bray, Melissa A.; Kehle, Thomas J. // School Psychology Review;2001, Vol. 30 Issue 1, p135 

    Reports on a long-tern follow-up of the effects of self-modeling on the reduction of stuttering in two groups of students. Percentage of the students who exhibited normal fluency and dysfluency after a four-year follow-up period; Number of students who maintained their treatment effects; Speech...

  • Stuttering. Benaroch, Roy // Pediatrics for Parents;2008, Vol. 24 Issue 8, p14 

    The article provides an answer to a question on how to help a kid from stuttering.

  • Interpreting results of the fluent speech paradigm in stuttering research: Difficulties in... Armson, Joy; Kalinowski, Joseph // Journal of Speech & Hearing Research;Feb94, Vol. 37 Issue 1, p69 

    Examines difficulties in interpreting results of studies that compare the fluent speech characteristics of stutterers and nonstutterers. Temporal parameters of fluent speech production; Context of experimental samples; Treatment history of subjects; Stuttering severity of subjects;...

  • Evaluating differences between stuttering and nonstuttering speakers: The group difference design. Young, Martin A. // Journal of Speech & Hearing Research;Jun94, Vol. 37 Issue 3, p522 

    Focuses on suggested analytical indices to be used in group difference research comparing stuttering with nonstuttering speakers. Relationship of group difference design to underlying conceptualizations of the nature of stuttering; Development, interpretation and application of the analytical...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics