Supplementary Information 1. Set of 64 Behaviours Used in Tool DevelopmentEarly Intervention (EI) Professional Items Rapport building 1. EI professional demonstrates empathy with the child and parent/caregiver 2. EI professional takes the lead with rapport building with the child and parent/caregiver 3. EI professional engages in small talk with the child and parent/caregiver Previous experience 4. EI professional asks the child and/or parent/caregiver about their previous experience with technology Expectations and goals 5. EI professional establishes the child and parent/caregiver's expectations and motivations for intervention 6. EI professional discusses the session goals with the parent/caregiver 7. EI professional explains each participant's role both inside and outside the session 8. EI professional highlights the importance of the parent/caregiver's role in early intervention Family-tailored service 9. EI professional demonstrates consideration of the child's additional needs while implementing activities where appropriate 10. EI professional makes comments/asks questions that show consideration of the child's identity and interests 11. EI professional makes comments/asks questions that show consideration of the family's identity and interests 12. EI professional uses activities that encourage the child to attend to stimuli 13. EI professional adjusts activities when appropriate to maintain the child's attention 14. EI professional involves the entire family unit in activities where appropriate Interaction 15. EI professional interacts with the child and/or parent/caregiver in a respectful and equal manner 16. EI professional interacts with the child and/or parent/caregiver in a warm and friendly manner 17. EI professional responds to the child's attempts to interact Input and collaboration 18. EI professional builds-up parent/caregiver's co-therapist skills for working with the child 19. EI professional encourages the child and/or parent/caregiver to actively participate throughout the session 20. EI professional builds-up support person's abilities for working with the child and/or parent/caregiver 21. EI professional encourages the child and/or parent/caregiver to ask questions
