Incredible Years Child Dinosaur Program

Study: Webster-Stratton, Reid, & Hammond (2004)

Study Type: Group-Design

Descriptive Information Usage Acquisition and Cost Program Specifications and Requirements Training

Dina Dinosaur's Social Skills, Emotion, and Problem-Solving Small Group Treatment Program (Dinosaur School) was developed to enhance children's appropriate classroom behaviors (e.g., quiet hand up, listening, following directions), promote social skills, emotional literacy, empathy and self-regulation, and positive peer interactions (e.g., waiting, taking turns, asking to enter a group, complimenting etc.), develop appropriate anger management strategies, and reduce conduct problems. It is organized to dovetail with the parent and teacher programs using the same developmental theory, language, and behavior management principles in order to promote consistency across settings. A classroom prevention version of the dinosaur program curriculum is offered 2-3 times a week in classrooms throughout the year with separate lesson plans for preschool, kindergarten, and early primary grade teachers.

This program is intended for use in kindergarten through 2nd grade. It is intended for use with students with disabilities, learning disabilities, intellectual disabilities, emotional or behavioral disabilities, ADHD, ODD, English language learners, and any student at risk for emotional and/or behavioral difficulties.

The areas of focus are externalizing and internalizing behavior. Externalizing behavior includes: physical aggression, verbal threats, property destruction, noncompliance, high levels of disengagement, disruptive behavior, and social behavior. Internalizing behavior includes: depression, anxiety, social difficulties, and school phobia.

Where to Obtain: Incredible Years

Address: 1411 8th Avenue West

Seattle, WA 98119

Phone: 206-285-7675


This program is designed for use with small groups of six students or with a classroom of students. Two interventionists are needed to implement the program.

Program administration time is 12 minutes, 1-2 sessions/week for 18-22+ weeks.

The program includes highly specified teacher manuals or instructions for implementation.

The program is affiliated with a broad school or class wide management program.

The program uses video vignettes as examples of prosocial behavior, problem solving and anger management.

It is necessary to have a computer or DVD player and flat screen to show vignettes to children which trigger problem solving and practices.

Three days of training plus ongoing consultation and video review are required for training interventionists.  The initial training is provided by an accredited mentor or trainer and is 3-days in length.  These training workshops take no more than 25 participants and are based on group discussion, video mediation, self-reflection, and multiple practices.

Following the 3-day training workshop, the group leaders/therapists are encouraged to video their group sessions for self-learning using a process checklist and to submit them for review by IY mentors and trainers.

Interventionists must be professionals. It is assumed that the interventionist has expertise in child development courses and knowledge of cognitive social learning theory.

Training manuals and materials are available.

Practitioners are encouraged to take advantage of telephone consultations with accredited coaches, mentors, or trainers. These may be telephone consultations, live on-site consultation, or video reviews of sessions. 


Participants: Convincing Evidence

Sample size: 56 students (30 program, 26 control)

Risk Status: Diagnosed as having ODD and/or CD on DSM-IV criteria by licensed psychologists.









Grade level



  Grade 1


  Grade 2





  Grade 3





  Grade 4





  Grade 5





  Grade 6





  Grade 7





  Grade 8





  Grade 9





  Grade 10





  Grade 11





  Grade 12





Mean Age











  American Indian





  Asian/Pacific Islander




















Socioeconomic status

  Subsidized lunch





  No subsidized lunch





Disability status

  Speech-language impairments


  Learning disabilities


  Behavior disorders


  Intellectual disabilities







  Not identified with a disability





ELL status

  English language learner





  Not English language learner
















Training of Instructors: Masters or PhD in social work, nursing, or psychology with 5-20 years experience.

Design: Convincing Evidence

Did the study use random assignment?: Yes

If not, was it a tenable quasi-experiment?: Not Applicable

If the study used random assignment, at pretreatment, were the program and control groups not statistically significantly different and had a mean standardized difference that fell within 0.25 SD on measures central to the study (i.e., pretest measures also used as outcomes)?: Yes

If not, at pretreatment, were the program and control groups not statistically significantly different and had a mean standardized difference that fell within 0.50 SD on measures central to the study (i.e., pretest measures also used as outcomes), and outcomes were analyzed to adjust for pretreatment differences?: Not Applicable

Were the program and control groups demographically comparable?: Yes

Was there differential attrition for the program and the control groups?: No   

Did the unit of analysis match the unit for random assignment (for randomized studies) or the assignment strategy (for quasi-experiments)?: Yes

Implemented with Fidelity: Convincing Evidence

Description of when and how fidelity of treatment information was obtained: Every session was videotaped and reviewed weekly. Group leaders/therapists completed weekly session protocols that included agenda, number of vignettes shown, small group practices completed, and homework given.

Results on the fidelity of treatment implementation measure: Fidelity was very high with over 90% of vignettes shown and practices conducted. Therapy sessions were either conducted by the developer or videos of sessions reviewed weekly by developer.

Measures Targeted: Partially Convincing Evidence

Targeted Measure

Reliability statistics

Relevance to program focus

Exposure to related support among control group

Child Conduct Problems at Home - Composite Score

cronbachs 0.78

Decrease behavior problems and increase social competence


Child Social Competence with Peers - Composite Score

cronbachs 0.52

Decrease behavior problems and increase social competence


Child Conduct Problems at School - Composite Score

cronbachs 0.84

Decrease behavior problems and increase social competence



Broader Measure

Reliability statistics

Relevance to program focus

Exposure to related support among control group






Mean ES Targeted Outcomes: 0.30*

Mean ES Administrative Outcomes: N/A

Effect Size:

Targeted Measures


Effect Size

Child Conduct Problems at Home - Mother

0.63 *

Child Conduct Problems at Home - Father


Child Social Competence with Peers


Child Conduct Problems at School



Broader Measures


Effect Size





*        p ≤ .05

**      p ≤ .01

***    p ≤ .001

–      Developer was unable to provide necessary data for NCII to calculate effect sizes

u      Effect size is based on unadjusted means

†      Effect size based on unadjusted means not reported due to lack of pretest group equivalency, and effect size based on adjusted means is not available


Visual Analysis (Single-Subject Designs): N/A

Disaggregated Outcome Data Available for Demographic Subgroups: No

Target Behavior(s): Externalizing, Internalizing

Delivery: Small groups (n=6), Classrooms

Fidelity of Implementation Check List Available: Yes

Minimum Interventionist Requirements: Professionals 3 days of training

Intervention Reviewed by What Works Clearinghouse: Yes – Intervention

What Works Clearinghouse Review

Children Identified With Or At Risk For An Emotional Disturbance Protocol

Effectiveness: The Incredible Years was found to have potentially positive effects on external behavior and potentially positive effects on social outcomes for children classified as having an emotional disturbance.

Studies Reviewed: 1 study meets standards out of 3 studies total

Full Report

Early Childhood Education for Children with Disabilities Protocol

Effectiveness: No studies of The Incredible Years that fall within the scope of the Early Childhood Education for Children with Disabilities review protocol meet What Works Clearinghouse (WWC) evidence standards. The lack of studies meeting WWC evidence standards means that, at this time, the WWC is unable to draw any conclusions based on research about the effectiveness or ineffectiveness of The Incredible Years on preschool children with disabilities in early education settings.

Studies Reviewed: N/A

Full Report

Other Research: Potentially Eligible for NCII Review: 0 studies