Implementation: fidelity, adaptation, and delivery logistics
Implementation is where design meets reality: recruitment, delivery quality, fidelity, adaptation, and documentation. Items test your judgement about the fidelity-versus-adaptation trade-off, instructional method choice, and what to do when delivery drifts.
Core rules
- Pilot test before scaling; then roll out in phases so problems surface while they are still cheap to fix.
- Fidelity has dimensions: adherence (core components delivered), dosage (amount and duration), quality of delivery, participant responsiveness, and programme differentiation.
- Adaptation is legitimate when it preserves core components and the rationale is documented. Changing providers, setting, language, or scheduling is usually surface structure; deleting content that drives the mechanism is not adaptation, it is a different programme.
- Method matches objective: lecture builds knowledge but retention is low; demonstration and role play build skills; rehearsal with feedback builds self-efficacy; teach-back verifies comprehension; print reinforces rather than teaches.
- Health literacy practice: plain language, roughly 5th–8th grade, chunk-and-check, teach-back, action-oriented visuals.
- RE-AIM names implementation as one of five dimensions alongside reach, effectiveness, adoption, and maintenance.
- Recruitment and retention barriers include transport, childcare, timing, cost, and trust; address them structurally (site, schedule, vouchers, reminders) rather than blaming participants.
- Document attendance, session logs, deviations, staff training, and supervision.
Worked example
A rural diabetes self-management course loses half its evening attendees. Process data (attendance logs, exit interviews) show shift workers and a two-bus trip. The response keeps the eight core sessions and their content but adds a second site, a Saturday cohort, bus vouchers, and trained community health workers delivering with supervision. Dosage and content are preserved; provider and setting are adapted. Reach is then tracked to check the fix worked.
Traps that cost marks
- Cutting core content to fit a shorter time slot and calling it tailoring.
- Framing low attendance as participant noncompliance instead of a design and access failure.
- Training staff once and never observing delivery quality.
- Undocumented adaptations, which make results impossible to interpret.