You are here

Incredible Years

A note on this page's publication date

The content we created in 2010 appears below. This content is likely to be no longer fully accurate, both with respect to the research it presents and with respect to what it implies about our views and positions.

Published: 2010

In a nutshell

  • The Program: Incredible Years is a set of group-based training programs for parents, teachers, and children that aims to promote 0-12 year-old children's social and emotional competence, and reduce their aggression and emotional problems (more).
  • Track record: There have been many rigorous evaluations of Incredible Years, finding positive effects on children's behavior. Note that we know of no long-term follow up assessing whether these results persist throughout the child's life (more).
  • Cost-effectiveness: Based on data from Invest in Kids, a charity implementing Incredible Years, we estimate a total cost-per-child-per-year served in Incredible Years programs of around $220. This figure only counts as costs program, administration, and fundraising costs to Invest in Kids, and costs to schools and parent groups for buying the program material kits. A cost-effectiveness study estimates a cost-per-child served in the Incredible Years parent program of around $2,200 to $3,900. These figures includes additional costs such as health, social care, and special education services used by the children (more).
  • Bottom line: While the Incredible Years has been evaluated in numerous randomized controlled trials, the lack of long-term follow up leaves us unsure that it has long-term, life-changing impacts.

Program description

Incredible Years is a group of programs that aim to promote social and emotional competence, and reduce aggression and emotional problems in children aged 0 to 12 years; thereby preventing later problems such as delinquency and drug abuse.1 Incredible Years consists of training programs for parents, children, and teachers.2

    The parenting programs target parents of children from 0 to 12 years of age.3 These parenting curricula or programs consist of approximately 4 to 20 weekly parent group sessions. Each parent group session has 2 group leaders, 10-14 participants, and lasts 2 to 2.5 hours.4

    The teacher program (the Teacher Classroom Management Program) targets teachers of children 3-8 years old and consists of six full day workshops, which take place once every 3 to 4 weeks.5 The program tries to improve teachers' classroom management skills, for example by providing instruction on how to use praise and incentives and how to teach empathy.6

    The child curriculum (the Dinosaur Curriculum) targets children 3-8 years old and trains children in skills such as empathy, friendship, anger management, and how to be successful at school.7 There are two versions of the curriculum: one is used for small groups of children that already have conduct problems, the other is for all students and is used in the classroom 2 to 3 times per week.8

The Incredible Years programs can be implemented by organizations or schools,9 which purchase the programs from Incredible Years. Each program consists of videos, manuals, books, take-home assignments, and handouts.10 The parent, teacher, and child groups are each supposed to have two group leaders.11 Although background requirements to become a group leader vary depending on program, a group leader should in general have prior training in child development, behavior management, and group process.12 They come from areas such as social work, psychology, nursing, and education.13 To become a group leader, one must also go through an Incredible Years certification process including peer-review, feedback, and a 2 to 3 day long training workshop.14

A certified group leader can get more training to become an Incredible Years Certified Mentor. Such mentors are authorized to give training to other group leaders.15 The training to become a mentor is provided by an Incredible Years Trainer, a certified group leader and mentor who is considered outstanding and has been selected to receive additional training.16

Evidence of effectiveness

Numerous randomized controlled trials (RCTs) have evaluated the Incredible Years program.17 We do not know of any rigorous evaluations that assess long-term results for the Incredible Years program—the longest follow-ups we are aware of were done 1 year after the intervention ended.18 We do not believe that positive, short-term results should be extrapolated to long-term results.19

We found no literature review that summarizes all of the studies of the Incredible Years programs, but we found several that each review a subset of the studies:

  • A 2006 review by the the Promising Practices Network, reviews the evidence of effectiveness of the parent and child programs.20 The review included 15 randomized controlled trials; seven assessed the effects of the BASIC Parent-Training component; six assessed the effects of variations on the BASIC Parent-Training component; and three assessed the small-group Dinosaur Child-Training program.21 The review concludes that the majority of the evaluations found large gains for participants, but the results were mostly short-term.22
  • A 2007 review by the National Registry of Evidence-Based Programs and Practices (NREPP) of Incredible Years includes six randomized studies.23 Parents in treatment groups that received parent training by itself or in combination with child and/or teacher training showed a "significant increase in positive and nurturing parenting," and "a significant reduction in harsh, coercive, and negative parenting" compared to the control groups.24 Children in treatment groups that received parent, child, and/or teacher training showed "a significant reduction in behavior problems at home or at school" and "a significant increase in positive behaviors at home or at school" relative to control groups.25
  • Shepard and Dickstein (2009) reviewed nine RCTs of Incredible Years that were conducted by the program developer Webster-Stratton and colleagues, and "a number of independent replications."26 Shepard and Dickstein (2009) similarly finds positive effects.27 Shepard and Dickstein (2009) concludes that "programs like IY [Incredible Years] that are delivered in group format in community settings have potential for providing highly effective prevention and intervention services to the large number of families in need."28
  • A Cochrane Collaboration review of parenting programs (including but not limited to Incredible Years) included three studies of the Incredible Years BASIC Parenting Program. It states, "all of the [eight] included studies had a number of methodological flaws compromising the generalisability of the findings."29 The Cochrane review concludes, "The findings of this review provide some support for the use of group-based parenting programmes to improve the emotional and behavioural adjustment of children with a maximum mean age of three years eleven months. The evidence concerning the long-term effects of improvements is inconclusive. It may be that during this period of rapid development, input at a later date is required. More research is needed to address this question."30

Is publication bias a concern?

We are in general concerned about publication bias, i.e. the possibility that studies are more likely to be published when they show positive results.

In the case of Incredible Years, we're worried about publication bias for two reasons:

  • Carolyn Webster-Stratton, author or co-author of many studies of the impact of Incredible Years is the program's developer, and her organization sells the Incredible Years programs.31
  • We are not aware of any formal study of publication bias in relation to the Incredible Years program. The Cochrane Collaboration review of parenting programs analyzes publication bias, but we cannot draw any conclusions from the analysis since it includes only three of the many studies of Incredible Years.32

What do you get for your dollar?

We base our estimates of the cost-effectiveness of the child program on data we received from Invest in Kids, an organization we have reviewed that runs the program.33 We estimate a total cost-per-child served in Invest in Kids' Incredible Years programs of around $220.34 This figure counts incorporates program, administration, and fundraising costs to Invest in Kids, as well as costs to schools and parent groups of buying the program material kits, but doesn't incorporate other costs, such as time costs to school teachers implementing the program.

Cost-effectiveness study of the parent program

Edwards et al. (2007) uses a study of the Incredible Years BASIC parenting program to conduct a cost-effectiveness analysis.35 The sample for this analysis was 116 children aged 3 and 4 years living in Wales, United Kingdom.36

Edwards et al. (2007) considers all the following costs:37

  • Non-recurrent (one-time) program costs, e.g. purchasing the program kit, training group leaders, and travel time to training course.
  • Recurrent (ongoing) program costs, e.g. supervision of group leaders and recruitment of parents.
  • Costs for health, social care, and special education services used by the children. Since the total non-program health, social care, and special education costs per child increased more in the program group than in the control group between baseline and 6 month follow-up, the amount such costs increased for the program group over and above the increase for the control group was included in the cost-effectiveness estimate.

The study estimates program costs both with and without one-time costs:

  • Including all one-time costs, the program costs between $2,579 or $3,868 per child, for the 12 children per group and 8 children per group programs, respectively.38
  • Excluding one-time costs, the cost per child is $2,218 or $3,192, for the 12 children per group and 8 children per group programs, respectively.39

Sources

  • 1.

    Incredible Years, "The Incredible Years: Parents, Teachers, and Children's Series: Program Overview – Fact Sheet," Pg 1.

    Incredible Years, "The Incredible Years Parent, Teacher and Child Programs: Overview of Program Details," Pg 1.

    The group of programs we call Incredible Years are also called the Incredible Years Series, or the Incredible Years Training Series. See the two references in this footnote.

  • 2.

    Incredible Years, "The Incredible Years Parent, Teacher and Child Programs: Overview of Program Details," Pgs 1-2.

  • 3.

    Incredible Years, "The Incredible Years Parent, Teacher and Child Programs: Overview of Program Details," Pg 1.

  • 4.

    Incredible Years, "The Incredible Years Parent, Teacher and Child Programs: Overview of Program Details," Pgs 1-2.

  • 5.

    Incredible Years, "The Incredible Years Parent, Teacher and Child Programs: Overview of Program Details," Pgs 1-2.

    Incredible Years, "Program Blocks: A Graphic of the Incredible Years Series."

    Incredible Years, "Incredible Years Teacher Training Programs."

  • 6.

    Incredible Years, "The Incredible Years: Parents, Teachers, and Children's Series: Program Overview – Fact Sheet," Pg 3.

    Incredible Years, "Program Blocks: A Graphic of the Incredible Years Series."

  • 7.

    Incredible Years, "Program Blocks: A Graphic of the Incredible Years Series."

    Incredible Years, "The Incredible Years: Parents, Teachers, and Children's Series: Program Overview – Fact Sheet," Pg 3.

  • 8.

    Incredible Years, "The Incredible Years: Parents, Teachers, and Children's Series: Program Overview – Fact Sheet," Pg 3.

    In Incredible Years, "Program Blocks: A Graphic of the Incredible Years Series," the first version is called Child Dinosaur Treatment Program, and the second is called Child Dinosaur Classroom Program.

    The Dinosaur Curriculum is also described at Incredible Years, "Incredible Years Child Training Series."

  • 9.

    "To successfully implement Incredible Years, the organization or school must be committed to excellence."
    Incredible Years, "The Incredible Years: Parents, Teachers, and Children's Series: Program Overview – Fact Sheet," Pg 3.

  • 10.

    "Each of the types of programs consists of videotapes, comprehensive facilitator manuals, books, take-home assignments, and handouts. It is recommended that all group participants (parents, teachers, children) have their own individual books and that facilitators have their own manuals. DVD equipment is necessary."
    Incredible Years, "The Incredible Years: Parents, Teachers, and Children's Series: Program Overview – Fact Sheet," Pg 3.

  • 11.

    "Each group should have two group leaders. Group leaders complete a certification/accreditation process that involves attendance at a certified training workshop, peer review, videotape feedback, and consultation."
    Incredible Years, "The Incredible Years: Parents, Teachers, and Children's Series: Program Overview – Fact Sheet," Pg 3.

  • 12.

    Incredible Years, "About Incredible Years Certification/Accreditation and the Process."

    Incredible Years, "Process for Becoming Certified/Accredited as a Group Leader."

  • 13.

    Incredible Years, "About Incredible Years Certification/Accreditation and the Process."

  • 14.

    Incredible Years, "The Incredible Years: Parents, Teachers, and Children's Series: Program Overview – Fact Sheet," Pg 3.

    Incredible Years, "About Incredible Years Certification/Accreditation and the Process."

    Incredible Years, "Process for Becoming Certified/Accredited as a Group Leader."

  • 15.

    Incredible Years, "Process to Become Certified as an Incredible Years Mentor."

  • 16.

    Incredible Years, "Process to Become Certified as an Incredible Years Mentor."

    Incredible Years, "Process for Becoming Certified as an Incredible Years Trainer."

  • 17.

    Incredible Years, "Evidence of Effectiveness."

    Incredible Years, "The Incredible Years Parent, Teacher and Child Programs: Overview of Program Details," Pgs 6-7.

  • 18.

    Studies with follow-up 1 year after intervention end include:

    • Gross et al. (2003)."Parents and children were assessed four times over a 15–18 month period (baseline, immediate postintervention, 6-months postintervention, and 1-year postintervention)." Gross et al. 2003, Pg 265.
    • Gardner, Burton, and Klimes (2006). Assessments "took place at three points: time 1, pre-intervention and pre-randomisation; 2, post-intervention (6 months later); 3, follow-up (18 months post-recruitment). The main group comparison by allocation is made at post-intervention. At 18-month follow-up, the progress of intervention children is described on all outcomes. However, randomised comparison with the control group is no longer possible, as the wait-list period is ended." Gardner, Burton, and Klimes 2006, Pg 1125.

    Webster-Stratton, Rinaldi, and Reid Forthcoming is a study with long-term follow-up but due to its study design, we don't consider it a rigorous study and draw no conclusions from it. It contacted 78 children who had received Incredible Years 8-12 years later and reassesed them on their social and emotional adjustment. There was no randomized control group but the study compared the program participants to some "national normative" samples. And "in addition to the normative samples presented above, we compared our teenagers (grades 7-12) to a similar age group of boys assessed in 8th grade and again in 10th grade who had participated in a longitudinal study (OYS; Wiesner, Kim, & Capaldi, 2005). These comparison boys had not been identified as having had early behavior problems like the children in our sample." Webster-Stratton, Rinaldi, and Reid Forthcoming Pg 17.

  • 19.

    For context, see our examples of fading impact.

  • 20.

    "The BASIC Parent-Training Program—Early Childhood component and the small-group Dinosaur Child-Training program have been rigorously evaluated, and the remainder of this description of the Incredible Years series focuses on these two components. The ADVANCE, BASIC—School Age, Supporting Your Child's Education, and school readiness parent-training components, the Teacher-Training program, and the Dina Dinosaur classroom curriculum currently do not have sufficiently rigorous research evidence that clearly assesses impacts on child outcomes." Promising Practices Network, "Incredible Years."

  • 21.

    Promising Practices Network, "Incredible Years."

  • 22.

    "The majority of the evaluations of these components [the BASIC Parent-Training—Early Childhood component and the Dinosaur Child-Training program] used rigorous standards, including randomized experimental design and control groups, and the participants experienced significant and sizeable gains across many of the behavioral and social outcomes. Few studies have assessed the effects of the Incredible Years programs versus the outcomes for a comparison group beyond two months after program completion (only three studies that went beyond a two-month follow-up were identified).... The findings from the evaluations of the Incredible Years programs are thus limited to mostly short-term results, and it is unknown whether the differences noted between treatment and control groups would be maintained in the longer run. However, the handful of longer-term studies reviewed did show some significant extended program effects. A handful of studies have examined combinations of Incredible Years components, but the results were inconclusive or mixed."
    Promising Practices Network, "Incredible Years."

  • 23.

    NREPP, "Incredible Years."

  • 24.

    "Parents in treatment groups that received the parent training by itself or in combination with the child and/or teacher training showed a significant increase in positive and nurturing parenting relative to parents in comparison groups (p

    "Parents in treatment groups that received the parent training by itself or in combination with the child and/or teacher training showed a significant reduction in harsh, coercive, and negative parenting relative to parents in comparison groups (p

  • 25.

    "Children in treatment groups that received parent training, child training, and/or teacher training showed a significant reduction in behavior problems at home or at school compared with controls (p

    "Children in treatment groups that received parent training, child training, and/or teacher training showed a significant increase in positive behaviors at home or at school compared with controls (p

  • 26.

    Shepard and Dickstein 2009, Pg 6.

  • 27.

    "In both treatment and prevention samples, parent participation in the original IY [Incredible Years] Basic parenting program resulted in sustained improvement in parents' self reports and independent observations of their behavior management skills compared with control groups, replacing use of harsh, ineffective parenting strategies with positive parenting, and improved observations of parent-child interactions and self reports of parent involvement. In turn, program participation led to reductions in observed and reported child conduct problems at home and school and increased compliance to parental commands among children ages 3 to 8 referred for treatment due to high levels of noncompliance, aggression, and/or oppositionality. Children in Head Start whose parents participated in the IY Parent groups, particularly those with initially elevated behavior problems, demonstrated enhanced social competence and reductions in negative affect, noncompliance and disruptive behaviors... A number of independent replications of the original IY Basic parenting program with both treatment and prevention samples report similar positive outcomes for parents and children's behavior at home and in daycare settings, improvements that were maintained up to two years following participation." Shepard and Dickstein 2009, Pg 6.

  • 28.

    Shepard and Dickstein 2009, Pg 15.

  • 29.

    Barlow et al. 2010, Pgs 7, 33.

    The 3 studies included in the review that evaluated Incredible Years BASIC Parenting Program were:
    Gross, Fogg, and Tucker 1995; Gross et al. 2003; Hutchings et al. 2007.

    Barlow et al. (2010) says regarding Hutchings et al. (2007) that a "source of bias identified in one study was that of a conflict of interest (Hutchings 2007), where the programme evaluator was also employed by the programme developer. It is not clear, however, to what extent this situation may have applied to other studies." Barlow et al. 2010, Pg 31.

  • 30.

    Barlow et al. 2010, Pg 2.

  • 31.

    "Dr. Carolyn Webster-Stratton is Professor and Director of the Parenting Clinic at the University of Washington. She is a licensed clinical psychologist and nurse-practitioner and over the past 30 years has conducted numerous randomized control group studies to evaluate the effectiveness of intervention programs for promoting social and emotional competence, school readiness skills and preventing conduct problems in high risk populations. She has also evaluated teacher, parent and child treatment programs for children diagnosed with Oppositional Defiant Disorder, Conduct Disorder and ADHD.

    She has developed the Incredible Years Series." Incredible Years, "About The Incredible Years."

    For publications by Carolyn Webster-Stratton on the effects of Incredible Years, see:
    Promising Practices Network, "Incredible Years."
    NREPP, "Incredible Years."

    In addition, Barlow et al. (2010) says that in a study of the effects of Incredible Years which doesn't include Webster-Stratton as author, the program evaluator was employed by the program developer. The review further says that it is not clear to what extent this may have applied to the other studies it reviewed:

    A "source of bias identified in one study was that of a conflict of interest (Hutchings 2007), where the programme evaluator was also employed by the programme developer. It is not clear, however, to what extent this situation may have applied to other studies." Barlow et al. 2010, Pg 31.

  • 32.

    The Cochrane review is Barlow et al. (2010). The 3 studies included in the review (which evaluated Incredible Years BASIC Parenting Program) were:
    Gross, Fogg, and Tucker 1995; Gross et al. 2003; Hutchings et al. 2007.

    "Selective reporting Bradley 2003 reported only the results that were statistically significant (i.e. only two out of four scales of the pre-school behaviour questionnaire (PBQ) are reported - total score and hyperactive/distractible subscale score). No indications of reporting bias were apparent in the remaining seven studies." Barlow et al. 2010, Pg 26.

    "Assessment of reporting biases
    Funnel plots (estimated differences in treatment effects against their standard error) were drawn. Asymmetry can be due to publication bias, but can also be due to a real relationship between trial size and effect size." Barlow et al. 2010, Pg 7.

    Barlow et al. (2010) is a review by The Cochrane Collaboration. The Cochrane Collaboration uses 'reporting bias' as a word for publication bias:

    "Publication bias. See Reporting bias." Cochrane Collaboration, "Glossary."

    "Reporting bias. A bias caused by only a subset of all the relevant data being available. The publication of research can depend on the nature and direction of the study results. Studies in which an intervention is not found to be effective are sometimes not published. Because of this, systematic reviews that fail to include unpublished studies may overestimate the true effect of an intervention. In addition, a published report might present a biased set of results (e.g. only outcomes or sub-groups where a statistically significant difference was found. Also called: Publication bias." Cochrane Collaboration, "Glossary."

  • 33.

    The two Incredible Years programs Invest in Kids implements are the school program and the parent training program: "The Incredible Years is divided into distinct training programs that are designed to enhance social competence and reduce aggression in young children aged three to eight years. The developmentally-appropriate and culturally-sensitive programs (e.g., Webster-Stratton, 2004) are the child social skills and teacher training program, known as the Dina Dinosaur Classroom Curriculum (referred to as the Dinosaur School program throughout this report), and the BASIC Parent Training Program (referred to as the Parent program)." OMNI Institute 2009, Pg 3.

  • 34.

    For details on how we estimated this cost-per-child see our review of Invest in Kids.

  • 35.

    Edwards et al. 2007, Pgs 1-2.

  • 36.

    Edwards et al. 2007, Pgs 1-2.

  • 37.

    Edwards et al. 2007, Pgs 3-4.

  • 38.

    Edwards et al. 2007, Pg 3. Edwards reports the figures (1289.04 and 1933.56) in British pounds. We converted these to 2007 dollars using the average 2007 exchange rate between pounds and dollars as reported by x-rates.com (X-rates.com, "Monthly Average Graph (British Pound, American Dollar) 2007").

  • 39.

    Edwards et al. 2007, Pg 3. Edwards reports the figures (1063.64 and 1595.46) in British pounds. We converted these to 2007 dollars using the average 2007 exchange rate between pounds and dollars as reported by x-rates.com (X-rates.com, "Monthly Average Graph (British Pound, American Dollar) 2007").