3–8 years.

The Incredible Years is a lineup of evidence-based early intervention programs for children ages 0–12, developed over more than 40 years of research. Alongside programs for parents and educators, it includes a series for children themselves known as the "Dinosaur School," which comes in two formats: a preventive version (for a whole class) and a treatment version (for small groups of children with already pronounced difficulties). Both versions share the same underlying methodology — puppets, a dinosaur theme, and learning through behavior modeling — but differ in format, audience, and duration.

The program helps children recognize and regulate their emotions, get along with peers, resolve conflicts, and become ready for school, while reducing behavioral difficulties in the classroom. The material is delivered through role-play scenes with puppets that model the desired behavior, group circle-time activities, and skill practice in small groups — these skills are reinforced not only during sessions but throughout the school day.

The classroom (preventive) version is divided into three difficulty levels by age (3–5, 5–6, and 7–8), with sessions held 2–3 times a week for 20–30 minutes in a "circle time" format followed by practice in small groups. A separate treatment version for small groups of 5–6 children with pronounced behavioral difficulties, ADHD, or emotional disorders is delivered by specialists (psychologists, therapists, special education teachers) once a week for two hours, for a total of 18–20 sessions — ideally run alongside the parent program.

The website does not provide an exact figure specifically for this program (Classroom Dinosaur) — only overall figures for The Incredible Years lineup as a whole: more than 66,600 group leaders have been trained since the program's founding, of whom more than 2,100 are currently active certified specialists.

36 countries — the reach of The Incredible Years program overall, including the parent, teacher, and child lineups, not just the classroom version.

The primary language of the materials is English; some materials have been officially translated into Spanish. According to the independent CEBC registry, the exact list of translated materials should be confirmed directly on the organization's website or with a program representative — no single list of languages is provided on the product page itself. (Spanish)

The program carries SELect status from CASEL — but only in combination with the teacher program "Teacher Classroom Management" (that is, the combination of the two programs is what qualifies, not the child version alone). It is also certified by the independent registry Blueprints for Healthy Youth Development with Certified Promising Program status.

A longitudinal randomized controlled study (published in 2008) covered 1,768 children from pre-kindergarten through grade 1 in urban Head Start centers and public schools in the western United States (58% received free or reduced-price meals, and 31% spoke a language other than English at home). After nine months, children who received both the teacher program and the child program together showed significant improvement in emotional self-regulation and social competence and a reduction in behavioral problems compared with the control group.

Another randomized controlled study covered 99 children ages 4–8 referred to a clinic with oppositional defiant or conduct disorder; participants were randomly assigned to four groups: child program only, parent program only, both combined, and a waitlist control group. Children's behavior was assessed at baseline, immediately after the intervention, and one year later.