An experimental investigation of the impact of the Lidcombe Program on early stuttering

Journal of Fluency Disorders27 (2002) 203–214

An experimental investigation of the impact ofthe Lidcombe Program on early stuttering

Vanessa Harrisa, Mark Onslowb,∗, Ann Packmanb,Elisabeth Harrisona, Ross Menziesc

a Stuttering Unit, Bankstown Health Service, Sydney, Australiab Australian Stuttering Research Center, The University of Sydney,

P.O. Box 1825, NSW 2141 Lidcombe, Australiac School of Behavioral and Community Health Sciences, The University of Sydney, Sydney, Australia

Received 25 September 2001; received in revised form 12 March 2002; accepted 14 March 2002

Abstract

Preliminary Phase I and II trials for the Lidcombe Program of early stuttering interventionhave found favorable outcomes and that the treatment is safe. Although speech–languagepathologists (SLPs) often need to intervene with pre-schoolers’ early stuttering, many ofthese children will recover at some time in the future without such intervention. Conse-quently, they need to know whether the Lidcombe Program’s effect on stuttering is greaterthan that of natural recovery. Participants were 23 pre-school children who were randomlyassigned to either a control group or a treatment group that received the Lidcombe Programfor 12 weeks. A repeated measures ANOVA showed no main effect on stuttering for thegroup (control/treatment), a significant main effect for the measurement occasion (at thestart and at the end of the treatment period), and a significant interaction between group andmeasurement occasion. Stuttering in the treatment group reduced twice as much as in thecontrol group. These results are interpreted to mean that the introduction of the LidcombeProgram has a positive impact on stuttering rate, which exceeds that attributable to naturalrecovery.

Educational objectives: Readers will learn about and be able to describe: (1) how nat-ural recovery can affect assessments of the effectiveness of treatments for early stuttering;(2) the relative effects of the Lidcombe Program and natural recovery on stuttering; and

∗ Corresponding author. Tel.:+61-2-9351-9061; fax:+61-2-9351-9392.E-mail address: [email protected] (M. Onslow).

0094-730X/02/$ – see front matter © 2002 Elsevier Science Inc. All rights reserved.PII: S0094-730X(02)00127-4

204 V. Harris et al. / Journal of Fluency Disorders 27 (2002) 203–214

(3) the difference between the results of this study and those of uncontrolled clinical trials.© 2002 Elsevier Science Inc. All rights reserved.

Keywords: Childhood stuttering; Lidcombe Program; Short-term effects

1. Introduction

The Lidcombe Program is a behavioral treatment for stuttering in pre-school-agechildren. The treatment is conducted by parents in the child’s everyday environ-ment and parents learn how to do the treatment during the weekly visits with thechild to the speech–language pathologist (SLP). A comprehensive description ofthe Lidcombe Program can be found inOnslow, Packman, & Harrison (in press).

In the Lidcombe Program, the parent gives verbal contingencies during con-versational exchanges with the child. These verbal contingencies are directed at:(1) stutter-free speech; (2) unambiguous stuttering; (3) correct self-evaluation ofstutter-free speech; and (4) spontaneous self-correction of stuttering. These ver-bal contingencies consist of: (1) acknowledgment and/or praise for periods ofstutter-free speech; (2) acknowledgment of stuttering and/or a request that the childcorrects stuttering; (3) praise for correct self-evaluation of stutter-free speech; and(4) praise for spontaneous self-correction of stuttering. The SLP ensures that theseparental verbal contingencies are not constant, intensive or invasive, and that par-ents are at all times positive and supportive of the child receiving the treatment.The treatment is individualized for each family and, as with any treatment fora childhood speech or language disorder, it is essential that the child enjoys thetreatment and finds it to be a positive experience.

Stuttering measures are an essential component of the Lidcombe Program. Theparent makes daily measures of the severity of the child’s stuttering on a 10-pointscale, where 1= no stuttering; 2= very mild stuttering; and 10= extremelysevere stuttering. The SLP makes weekly measures of stuttering rate (percentsyllables stuttered, %SS). Together, these two measures are used to: (1) guideimplementation of the program from week to week; (2) identify when the child hasmet criterion speech performance; and (3) check that the child’s speech continuesto meet criterion speech performance in the long-term. The stuttering measuresalso enable the SLP and the parent to communicate effectively about the severityof the child’s stuttering throughout the treatment process.

The Lidcombe Program is conducted in two stages. Stage 1 is complete whenthe child’s stuttering is below 1.0%SS and each of the daily severity ratings forthe corresponding week are either 1 or 2, with the majority being 1. During Stage2, the parent gradually withdraws the verbal contingencies and gradually assumescomplete responsibility for the treatment as visits to the clinic decrease in fre-quency. Any departure from the criterion speech performance, as specified withthe stuttering measures at the end of Stage 1, results in more frequent clinic visitsand possibly an increase in parental contingencies.

V. Harris et al. / Journal of Fluency Disorders 27 (2002) 203–214 205

A file audit of 250 children treated with the Lidcombe Program (Jones, Onslow,Harrison, & Packman, 2000) showed that the mean number of weekly clinic visitstaken to complete Stage 1 was 12.5, and a recovery plot for these children showedthat 90% of them had completed Stage 1 after 22 clinic visits. Jones et al. found thatpre-treatment stuttering rate was the only predictor of time required to completeStage 1. Other case variables — most notably time since reported onset — did notaffect the time taken to complete Stage 1.

The safety and clinical promise of the Lidcombe Program have been establishedin Phase I and II (Pocock, 1996) trials. Non-controlled trial data (Onslow, Andrews,& Lincoln, 1994; Onslow, Costa, & Rue, 1990) and file audit data (Jones, Onslow,Harrison, & Packman, 2000) have shown outcomes of zero or near zero ratesof stuttering in children in the medium-term after treatment with the LidcombeProgram. Long-term data on 42 children (Lincoln & Onslow, 1997) show outcometo be durable. The social validity of treatment outcomes has been established(Lincoln, Onslow, & Reed, 1997). Given that the Lidcombe Program is a directtreatment, it is perhaps not surprising that concerns have been expressed aboutits safety (Cook, 1996; Cook & Rustin, 1997). Consequently,Woods, Shearsby,Onslow, and Burnham (2002)demonstrated that the treatment was not associatedwith psychological harm to children.

To date, however, the efficacy of the Lidcombe Program has not been estab-lished. In other words, there is no unequivocal evidence that the reductions instuttering that occur with the Lidcombe Program are in fact due to the treatment.The most important issue to consider in determining the effectiveness of treatmentsfor early stuttering is, of course, natural recovery. Here, there are two questions(Packman & Onslow, 1998). The first is whether recovery from stuttering withthe Lidcombe Program is greater than natural recoveryin the long-term. In otherwords, after a clinically significant post-treatment period, are the improvementsin stuttering that occur after treatment with the Lidcombe Program greater thanthose of natural recovery? The definitive answer to this question would involvecomparing a group of children who receive no treatment with a group of childrenwho receive treatment with the Lidcombe Program. In light of the fact that naturalrecovery may take 2 years or longer (e.g.,Ingham & Riley, 1998; Yairi & Ambrose,1999), this would involve withholding treatment for a control group of children fora number of years. This cannot be justified on ethical grounds, so the next best thingis to compare the Lidcombe Program with another treatment or treatments. Con-sequently, a Phase III (Pocock, 1996) randomized controlled trial of the programis in progress in New Zealand (Jones, Gebski, Onslow, & Packman, 2001).

A second, and equally important question about effectiveness concerns theimmediate effects of this treatment:When the Lidcombe Program is introduced,are its effects on the course of the disorder greater than the effects of naturalrecovery? Natural recovery occurs in many cases of early stuttering, with tworecent estimates lying in the mid-70% range (Mansson, 2000; Yairi & Ambrose,1999). At present, however, there is some doubt that recovery rates for childrenwho present to a clinic would be as high as those population estimates. In any


event, in many instances SLPs will want to implement treatment sometime duringthe pre-school years, despite not knowing whether the child is destined to recovernaturally. There are many reasons for clinicians to treat a pre-school child whostutters, even though there is a chance that natural recovery may occur at somefuture time (Packman & Onslow, 1999; Packman, Onslow, & Attanasio, in press).Consequently, there is need for evidence that the immediate reductions in stutteringobserved with the Lidcombe Program can be attributed primarily to the treatmentrather than to natural recovery. An experimental design is required to establishthis evidence. Such a design involves withholding treatment for a control group,but only for a short period, and would determine whether the Lidcombe Programprovides short-term benefits beyond what might be expected from natural recovery.

The present paper reports such an experimental investigation. In this study,a group of children who receive the Lidcombe Program over 12 clinic visits iscompared with a control group of children who receive no treatment for 12 weeks.Twelve clinic visits was chosen as this is close to the mean number of clinic visits(12.5) taken by pre-school children to complete Stage 1 of the Lidcombe Program(see earlier). Of course, not all children receiving the Lidcombe Program in thestudy would be expected to complete Stage 1 within 12 clinic visits, but this wasconsidered a sufficient period to demonstrate the impact of the treatment on thenatural course of stuttering.

2. Method

2.1. Participants

The participants were 23 children assessed at the Stuttering Unit, BankstownHealth Service, and Campbelltown Hospital, Macarthur Health Service, in Syd-ney. The children lived in a range of suburbs in metropolitan Sydney of varyingsocio-economic levels. All children came to the clinic originally for stuttering,except for one child in the experimental group who presented with mild speechand language problems and who was found at assessment to be stuttering. At theconclusion of the experiment, one control child received additional treatment forlanguage and voice problems, and one experimental child received additional treat-ment for articulation and language. The post-experiment treatment history of oneexperimental child and one control child was not available.

Potential subjects were screened against selection criteria, which were: (1)age between 2 years 0 months and 4 years 11 months; (2) no previous treatmentwith the Lidcombe Program or professional consultation involving the LidcombeProgram; (3) 6 months or longer since reported onset of stuttering; (4) English thefirst language for both parents and child; and (5) stuttering at a rate of 3.0%SS orgreater within the clinic during a conversation with the first investigator or a parent.For criterion (5), stuttering rate in %SS was obtained from an audio recording ofa within-clinic speech sample recorded while the child played in the clinic at the


assessment interview. Potential subjects at the Stuttering Unit were recruited inthe order in which parents telephoned to request treatment for their child. Potentialsubjects from Campbelltown Hospital were recruited in order from a list of childrenwaiting for assessment. Potential subjects were assessed during an interview withthe first investigator.

2.2. Procedure

Parents of children who met selection criteria at the assessment interview wereinformed about the study and asked if they wished to participate. Parents were toldthat: (1) they would be randomly allocated to either an experimental (treatment)group or a control (non-treatment) group; (2) participation in the study wouldlast approximately 12 weeks; and (3) at the completion of the study, childrenallocated to the treatment group would continue on the program and children inthe control group would receive treatment when their name came to the top of theclinic waiting list. Parents who agreed to participate were supplied with a smallaudiotape recorder and instructions to make 10 min beyond-clinic recordings inthree situations during the following week. In these situations the child was tospeak: (1) with a parent; (2) with a familiar person other than a parent, away fromhome; and (3) at any location with a familiar person without the child’s knowledgeof the recording.

At the assessment interview, information about the nature of stuttering wasprovided to parents but no detailed information was provided about either theLidcombe Program or any other stuttering treatment. Parents were advised onlythat the Lidcombe Program is presented by parents and involves weekly visits tothe speech clinic. An appointment was made for the following week and parentswere advised that their child would be randomly allocated to either the treatmentor the control group when they returned at that time with all three tape recordingscompleted. No advice was given to any parent about how to react to or otherwisedeal with the child’s stuttering.

Children were randomly allocated to either the treatment group or the con-trol group at the beginning of the first clinic visit after the interview assessmentvisit, provided parents had made and produced the three beyond-clinic recordings.Randomization was performed independently at the Clinical Trials Center of theNational Health and Medical Research Council of Australia. The first investigatortelephoned the Clinical Trials Center, where the child was randomized using ablocked randomization design. As this was an experiment and not a clinical trial,an a priori decision was made that randomization would continue until there wereat least 10 subjects in each group, even if that resulted in uneven group numbers.Subject numbers were not based on power calculations, because, as is often thecase with a low incidence disorder such as stuttering (Jones, Gebski, Onslow, &Packman, 2002), requisite numbers of clinical subjects for adequate power wereprohibitive in terms of feasibility for an initial study. In the present case, greaterthan 60 subjects per group would be required to detect a medium effect at power


0.8 andα 0.05. Instead, subject numbers were chosen so that the present studycould serve to determine the viability of a larger scale project in the event that datawere non-significant in the presence of apparent trends (Jones, Gebski, Onslow, &Packman, 2002).

Children allocated to the treatment group began their 12 clinic visits imme-diately. For these children, one within-clinic recording and three beyond-clinicrecordings were again made, in the same speaking situations, after the requisite 12clinic visits. The parents of the control group children were scheduled to return tothe clinic 12 weeks post-randomization. During this visit, a within-clinic record-ing was made, and the parents presented the required set of three beyond-clinicrecordings made during the previous week.

2.3. Dependent measure

The dependent measure was %SS. In contrast to definition-based measuresof stuttering, the measure of %SS records the number of speech events thoughtby an experienced clinician to be unambiguous stuttering (Jones, Gebski,Onslow, & Packman, 2001). The %SS does not include counts of normal dis-fluencies. Measures of %SS were made by an SLP experienced in treating andmeasuring stuttering, who was independent of the study and had no knowledgeof the participants. The clinician knew the topic of the research but not its de-tails. Recordings were presented blind, in random order, to this clinician withpre-treatment and post-treatment status also randomized. The mean %SS scoresfor each child at 1 week pre-randomization (first measurement occasion) and at 12weeks post-randomization (second measurement occasion) were calculated, basedon the four tape recordings (three made beyond the clinic and one made within theclinic).

Pre- and post-randomization within-clinic recordings for all children were se-lected for intrajudge reliability analysis. These 46 recordings, comprising arounda quarter of the total recordings, were presented to the SLP for re-measurement, 1month after the original measures were made. Interjudge reliability was establishedby a second SLP, who was also experienced in treating and measuring stuttering,and who was also independent of the study and had no knowledge of the partic-ipants. This clinician also knew the topic of the research but not its details. ThisSLP also made blind measurements from randomly arranged recordings. It wasdetermined a priori that around one-third of the recordings would be included inthe interjudge reliability analysis. Tapes were selected randomly from the pool ofrecordings and presented to the SLP for measurement.

3. Results

Twenty-nine children were randomized to the experiment. Of these, six childrendid not complete the experimental procedures, for the following reasons: death in


Table 1Number, gender, mean %SS and mean time since onset for the control and the treatment groups

Number Mean %SSpre-randomization

Mean time sinceonset (months)

Boys Girls

Control 11 2 8.4 10Treatment 8 2 8.6 12

the family, failure to comply with experimental procedures, treatment sought closerto home and loss of contact with the family. This left 10 children in the treatmentgroup and 13 in the control group. Information about the children is shown inTables 1 and 2.

Table 2The columns display, for individual children, gender, reason for individual referral, treatment sub-sequent to the experiment for communication disorders other than stuttering, months since reportedonset, and reported history of stuttering in first- or second-degree relatives

Subject Group Gender Originalreferral

Subsequenttreatment

Months sincereported onset

Reportedfamilyhistory

1 Control M Stuttering No 9 Unknown2 Control M Stuttering Language/

voice12 Yes

3 Control M Stuttering No 10 Yes4 Control M Stuttering No 6 Unknown5 Control M Stuttering No 12 Unknown6 Control F Stuttering No 12 No7 Control M Stuttering No 12 Yes8 Control M Stuttering No 12 Yes9 Control M Stuttering No 6 Yes10 Control M Stuttering No 12 Yes11 Control M Stuttering History

unavailable12 Yes

12 Control F Stuttering No 6 Yes13 Control M Stuttering No 9 Yes14 Experimental M Stuttering No 12 Yes15 Experimental M Stuttering History

unavailable12 Yes

16 Experimental M Mild articulation/language

Language 6 Yes

17 Experimental F Stuttering No 16 Yes18 Experimental M Stuttering No 11 Yes19 Experimental M Stuttering No 12 Yes20 Experimental M Stuttering No 8 Yes21 Experimental M Stuttering No 12 No22 Experimental M Stuttering No 13 Yes23 Experimental F Stuttering No 18 Yes


Of the 184 recordings scheduled in the experiment (23 children×4 recordings×2 assessment occasions), 178 (96.7%) were obtained by the investigators and usedfor data collection. The mean duration of tape recordings of the children was9.2 min. The mean number of syllables counted on the recordings during the col-lection of %SS scores was 448 (S.D. = 159; range, 93–959). In order to avoidmultiple statistical comparisons within a small data set, and in order to minimizethe effects of the variability of early stuttering on analysis procedures, the stutter-ing rates for each child pre- and post-randomization were based on means of fourrecordings. Therefore, mean %SS scores in the analysis were generally based onspeech samples in excess of 1500 syllables.

Of the 46 samples re-measured for intrajudge reliability, 37 (78.7%) differed byless than 1.0%SS, 46 (97.9%) differed by less than 2.0%SS, and 46 (100%) differedby less than 3.0%SS. The Pearson correlation between the original ratings and theseratings was 0.99. Of the 66 samples re-measured by the independent clinicianfor interjudge reliability analysis, 18 (27.3%) differed by less than 1.0%SS, 39(59.1%) differed by less than 2.0%SS, and 55 (83.3%) differed by less than 3.0%SS.The Pearson correlation between the original ratings and these ratings was 0.83.The results of intrajudge and interjudge reliability analyses showed that overallmeasurement error for %SS was likely to be small in relation to the data trendsdetected in the study (seeFig. 1), and that data trends pre- to post-randomizationwould be detectable with the %SS measure.

The mean %SS scores for the treatment and the control groups at the pre-rando-mization measurement occasion were 8.6 (S.D. = 5.2; range, 2.6–20.1) and 8.4(S.D. = 2.5; range, 3.6–13.1) respectively, and at the post-randomization mea-surement occasions were 3.5 (S.D. = 2.8; range, 0.6–9.2) and 5.8 (S.D. = 3.6;range, 2.3–15.3), respectively. Nine of the 10 experimental children reduced their

Fig. 1. Mean %SS scores for the treatment and control group pre-randomization and post-randomization.


%SS score from pre- to post-randomization, with the mean change in those chil-dren being a 39% reduction of the pre-randomization %SS score. The remainingparticipant’s pre-randomization score increased by 16%. Nine of the 13 controlchildren reduced their %SS score from pre- to post-randomization, with the meanchange in those nine children being a 26% reduction of the pre-randomization%SS score. The other four control children increased their stuttering rates by 54,20, 42, and 6% of the pre-randomization score.

As expected, %SS data were skewed (Jones, Onslow, Harrison, & Packman,2000). Normally distributed data are necessary for the calculation of variances inANOVA. Hence, data were log transformed to produce a normal looking distribu-tion and analyzed with a repeated measures ANOVA. There was no main effectfor group (control/treatment;F = 3.13,P > 0.05). In other words, there was nodifference between the groups when both pre- and post-randomization %SS scoreswere taken into account. There was a significant main effect for measurement oc-casion (pre- and post-randomization;F = 28.32, P < 0.001). This means thatwhen %SS scores for both groups are combined, there was a significant decrease instuttering from the first to the second measurement occasion. There was a signifi-cant interaction between group and measurement occasion (F = 5.02,P < 0.05).In other words, the treatment group improved significantly more than the controlgroup from the first to the second measurement occasion. The significant interac-tion is displayed inFig. 1.

4. Discussion

The long-term effects of the Lidcombe Program are being studied in theJones,Gebski, Onslow, & Packman (2001)clinical trial. The present study dealt withshort-term effects, and showed that the improvement in stuttering in a group ofpre-school-age children after a set number of clinic visits in the Lidcombe Programwas greater than the effect of natural recovery. In other words, the results indicatethat the treatment has an immediate impact on the natural course of the disorder.While some reduction in %SS scores occurred in the children who did not receivetreatment, the decrease in stuttering in the treated group was around twice thatamount. These results show that clinicians can be confident that implementing theLidcombe Program will have a positive impact on stuttering rate in their pre-schoolclients.

Stuttering frequency was the only dependent variable in the present study, sothese results offer no explanation for why the treatment might be effective. Noattempt was made to investigate reasons for the improvement in either group inthis study, because measures of stuttering were made only after 12 weeks andbefore the completion of treatment, which is not a suitable design for such aninvestigation. Nonetheless, the reasons for recovery from stuttering during theLidcombe Program is an interesting issue. At present, preliminary data suggest thatneither extensive change in children and parents’ language habits (Bonelli, Dixon,


Bernstein Ratner, & Onslow, 2000), nor changes in speech acoustics (Onslow,Hewat, McLeod, & Packman, 2002), are associated with the treatment. The useof the present controlled experimental method would be an effective means forcontinuing this search for any changes in children or their parents that mightexplain the effects of the Lidcombe Program.

The design of this experiment involved randomizing children, as they enteredthe study, either to the treatment group or the control group. This design, which isa true experimental design, was chosen in preference to a matched cohort design,which is a quasi-experimental design. The experimental design was chosen becauseit eliminates bias. It might be argued that children in a study such as the presentone should be matched on variables such as stuttering rate, age, time since onsetof stuttering, gender, and family history of recovery from stuttering. It could alsobe argued that they should be matched for cognitive, language and phonologicaldevelopment. Matching on so many variables would be unmanageable, and failureto match on any or all of them would leave the design open to the effects of bias.Even if matching on all such variables were to be achieved, there may be othervariables, yet unknown to us, that might bias the results of such a study.

The control children, as a group, showed some improvement in stuttering duringthe period of study, yet it is difficult to interpret this result considering that theseare the first reported clinical measures of %SS over so short a period for a group ofstuttering pre-school children who do not receive treatment. It may well be the casethat some of the children in the control group who showed clinically significantstuttering reductions during the period of study may have continued that trend andrecovered from the condition in a timely fashion. The present results raise the needto explore this issue in further clinical investigations.

References

Bonelli, P., Dixon, M., Bernstein Ratner, N., & Onslow, M. (2000). Child and parent speech and languageand the Lidcombe Program of early stuttering intervention.Clinical Linguistics and Phonetics, 14,427–446.

Cook, F. (1996). The Lidcombe Programme: Is this the cure?Bulletin of the Royal College of Speechand Language Therapists, 528, 14.

Cook, F., & Rustin, L. (1997). Commentary on the Lidcombe Program of early stuttering intervention.European Journal of Disorders of Communication, 32, 250–258.

Ingham, J. C., & Riley, G. (1998). Guidelines for documentation of treatment efficacy for young childrenwho stutter.Journal of Speech, Language, and Hearing Research, 41, 753–770.

Jones, M., Gebski, V., Onslow, M., & Packman, A. (2001). Design of randomized controlled trials:Principles and methods applied to a treatment for early stuttering.Journal of Fluency Disorders,26, 1–21.

Jones, M., Gebski, V., Onslow, M., & Packman, A. (2002). Power in health research: A tutorial.Journal of Speech, Language, and Hearing Research, 45, 243–255.

Jones, M., Onslow, M., Harrison, E., & Packman, A. (2000). Treating stuttering in children: Predictingtreatment time in the Lidcombe Program.Journal of Speech, Language, and Hearing Research,43, 1440–1450.

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Lincoln, M., Onslow, M., & Reed, V. (1997). Social validity of an early intervention for stuttering: TheLidcombe Program.American Journal of Speech–Language Pathology, 6, 77–84.

Mansson, H. (2000). Childhood stuttering: Incidence and development.Journal of Fluency Disorders,25, 47–57.

Onslow, M., Andrews, C., & Lincoln, M. (1994). A control/experimental trial of an operant treatmentfor early stuttering.Journal of Speech and Hearing Research, 37, 1244–1259.

Onslow, M., Costa, L., & Rue, S. (1990). Direct early intervention with stuttering: Some preliminarydata.Journal of Speech and Hearing Disorders, 55, 405–416.

Onslow, M., Hewat, S., McLeod, S., & Packman, A. (2002). Speech segment timing in children after theLidcombe Program of early stuttering intervention.Clinical Linguistics and Phonetics, 16, 21–33.

Onslow, M., Packman, A., & Harrison, E. (in press).The Lidcombe Program of early stutteringintervention: A clinician’s guide. Austin, TX: Pro-Ed.

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Packman, A., & Onslow, M. (1999). Issues in early intervention. In M. Onslow & A. Packman (Eds.),Handbook of early stuttering intervention. San Diego, CA: Singular Publishing Group.

Packman, A., Onslow, M., & Attanasio, J. (in press). The timing of intervention with the LidcombeProgram. In M. Onslow, A. Packman, & E. Harrison (Eds.),The Lidcombe Program of earlyintervention: A clinician’s guide. Austin, TX: Pro-Ed.

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CONTINUING EDUCATION

An experimental investigation of the impact of the Lidcombe Program onearly stuttering

QUESTIONS

1. This experiment was designed to determine:a. the long-term effects of the Lidcombe Program on stutteringb. the short-term effects of the Lidcombe Program on stutteringc. the long-term effects of natural recovery on stutteringd. the short-term effects of natural recovery on stutteringe. the relative effects of the Lidcombe Program and natural recovery on

stuttering2. The Lidcombe Program of early stuttering intervention is:

a. a speech-pattern change procedureb. a procedure where demands on the child are reducedc. a behavioral treatmentd. a cognitive-behavior treatmente. all of the above

3. In this experiment, the dependent variable was:a. the group to which the children were assignedb. percentage of syllables stuttered


c. stuttering severity measured on a 10-point scaled. syllables per minutee. “b” and “d” above

4. The design of this experiment was:a. a randomized controlled designb. a quasi-experimental designc. a crossover designd. a double-blind designe. none of the above

5. In this experiment, children in the treatment group reduced their stuttering:a. almost to the same extent as the control childrenb. twice as much as the control childrenc. half as much as the control childrend. more than any other treatment group studiede. more than one of the above

An experimental investigation of the impact of the Lidcombe Program on early stuttering

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