Linking implementation of evidence-based parenting programs to outcomes in early intervention.

Morrison et al. (2017) tracked how closely early-intervention staff followed a manualized parenting program. They also asked parents how much of the program they received and how much they liked it.

All families had toddlers with developmental delays. The team wanted to see which parts of implementation predicted better parenting style at the end.

The more staff stuck to the script, the worse parents scored on parenting-style measures. Dosage and satisfaction had no clear effect.

In short, rigid fidelity backfired. Relationship quality seemed to matter more than perfect adherence.

Abouzeid et al. (2020) ran a similar parent-coaching program and saw the opposite: high fidelity went hand-in-hand with better parent skills. The difference may be the model—Nadia used ESDM which builds in flexibility, while E’s program demanded stricter script use.

Smit et al. (2019) boosted parent interaction by adding motivational interviewing and home visits. Their trial shows that extra relationship-focused supports, not just fidelity, drive parent gains.

Yi et al. (2021) and Van der Donck et al. (2023) both looked at telehealth ABA coaching. Yi found low fidelity; Stephanie hit 95% by adding live feedback. Together they echo E’s warning: manuals alone are not enough—real-time collaboration counts.

If you coach parents of young children with delays, loosen your grip on the script. Watch for parent comfort and engagement first, then layer in procedures. Schedule check-ins to ask, “Does this feel doable?” Adjust the pace before perfecting each step. High fidelity that feels robotic can hurt the very parenting style you want to improve.