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Updated: Aug 18, 2026

Measuring the Functional Abilities of Children Aged 3-6 Years Old with Observational Methods and Computer Tools
Published on: June 20, 2020
Assessing mobility in children using a computer adaptive testing version of the pediatric evaluation of disability
Stephen M Haley1, Anastasia E Raczek, Wendy J Coster
1Health and Disability Research Institute, Boston University, Boston, MA, USA. smhaley@bu.edu
Objective:
To assess score agreement, validity, precision, and response burden of a prototype computerized adaptive testing (CAT) version of the Mobility Functional Skills Scale (Mob-CAT) of the Pediatric Evaluation of Disability Inventory (PEDI) as compared with the full 59-item version (Mob-59).
Design:
Computer simulation analysis of cross-sectional and longitudinal retrospective data; and cross-sectional prospective study.
Setting:
Pediatric rehabilitation hospital, including inpatient acute rehabilitation, day school program, outpatient clinics, community-based day care, preschool, and children's homes.
Participants:
Four hundred sixty-nine children with disabilities and 412 children with no disabilities (analytic sample); 41 children without disabilities and 39 with disabilities (cross-validation sample).
Interventions:
Not applicable.
Main Outcome Measures:
Summary scores from a prototype Mob-CAT application and versions using 15-, 10-, and 5-item stopping rules; scores from the Mob-59; and number of items and time (in seconds) to administer assessments.
Results:
Mob-CAT scores from both computer simulations (intraclass correlation coefficient [ICC] range, .94-.99) and field administrations (ICC=.98) were in high agreement with scores from the Mob-59. Using computer simulations of retrospective data, discriminant validity, and sensitivity to change of the Mob-CAT closely approximated that of the Mob-59, especially when using the 15- and 10-item stopping rule versions of the Mob-CAT. The Mob-CAT used no more than 15% of the items for any single administration, and required 20% of the time needed to administer the Mob-59.
Conclusions:
Comparable score estimates for the PEDI mobility scale can be obtained from CAT administrations, with losses in validity and precision for shorter forms, but with a considerable reduction in administration time.

