UOT-P is based on the foundational principles of UOT for improving EF as well as evidence-based teaching methods (e.g., positive behavior supports, visual aids). Through this program, children, teachers and parents develop a shared self-regulatory vocabulary that enables children to improve EF at home and school through adult modeling and gradual scaffolding. The self-regulatory vocabulary (e.g., Flexible, Make a New Plan, Unstuck) becomes a "contagious" common language. We hypothesize this is the mechanism of change by which children will show improved EF skills, leading to increased academic readiness, improved social competence and reduced externalizing behaviors.

Children at clinic sites beginning in Year 4 will be placed in Arm 2, in which a waitlist control model will be used. Assessment of participants on outcome measures will occur at pre-intervention, followed by a 16-week waitlist period, again at baseline, followed by a 16-week intervention, and then finally at endpoint. All participants in Arm 2 will receive UOT-P as their intervention (see Experimental Arm).

Unstuck & On Target: Preschool (UOT:P) is a group-based curriculum for preschool and kindergarten students that targets executive function skills using CBT techniques. The UOT-P curriculum consists of 16 child small-group or classroom-wide lessons. Each lesson follows a clear structure in which the theme for the session is introduced in a storybook, supported with manipulatives and visuals. Children implement the skills introduced in the storybook through joing play activities that require them to flexibly adjusting their plans to work together. Children learn key vocabulary and active coping and problem-solving skills, with adult modeling and scaffolding, that enable them to build early executive functioning skills for self-regulation and classroom participation.

Interventionist ratings of feasibility will serve as the primary outcome measure. Interventionists will rate overall intervention feasibility using the Feasibility of Intervention Measure (FIM) at outcome. Scores range 4-20, where higher scores indicate higher feasibility.

Child attendance at groups will also be tracked.

Acceptability will be measured via interventionist ratings on the Acceptability of Intervention Measure (AIM). Scores range from 4-20, where higher scores indicate higher acceptability.

Acceptability will be measured via interventionist ratings on the the Intervention Appropriateness Measure (IAM) at outcome.

The Unstuck Treatment Implementation Measure will be used to assess interventionist fidelity. Standardized observations will be conducted, with ratings of fidelity on a Likert scale across several dimensions.

This is a development trial, and thus primary outcomes assess feasibility and acceptability. However, preliminary investigation of child-level outcomes will also be undertaken. Classroom teachers will respond complete the CBRS, which uses a Likert scale to rate children's classroom behaviors for engagement with academic tasks, adults, and peers.