Table 3.

Outcome Measures Pertaining to Aim 2^a

Measure	Administration Time	Description
Automated device-use datab	No additional administration time	Frequency and duration of activation, average speed, and distance traveled Collected via a custom data logger (attached to the modified ride-on cars) and a GPS + accelerometer unit attached to the Permobil Explorer Mini
Daily driving diary	<5 min/d	Caregiver form indicating: 1. The date, time, and environment of device use 2. General activities the child engaged in while using the device 3. The child’s enjoyment level
Individual, semistructured interviews	30–45 min	A semistructured interview to explore: 1. Caregiver experiences regarding use of each powered mobility device 2. Perceived barriers encountered and solutions discovered 3. Perceptions of self-efficacy and behavioral capacity Two key questions will provide insight as to caregiver perceptions of their child’s emerging agency and powered mobility devices over time65,66: 1. “Can you describe [child’s name] for me?” 2. “How do you think your child will respond/responded to power mobility training?”Interviews will be audio recorded and transcribed verbatim
A 3-measure perceptual implementation outcome survey: acceptability, appropriateness, feasibility	5 min total	1. The AIM measures acceptability, ie, how receptive stakeholders are to adopting an intervention 2. The IAM measures appropriateness, ie, the suitability of the intervention in a given environment or circumstance 3. The FIM is designed to measure feasibility (how possible and likely stakeholders are to adopt an intervention). All 3 surveys have substantive and discriminative content validity, construct validity, internal consistency, and test–retest reliability.49

^a Aim 2: to compare use patterns of the Explorer Mini and a modified ride-on toy car. AIM = Acceptability of Intervention Measure; FIM = Feasibility of Intervention Measure; GPS = global positioning system; IAM = Intervention Appropriateness Measure.

^b Indicates primary outcome.