An Item Response Theory-Based, Computerized Adaptive Testing Version of the MacArthur-Bates Communicative Development...

Area of Science:

• Psychometrics
• Developmental Psychology
• Speech-Language Pathology

Background:

• The MacArthur-Bates Communicative Development Inventory: Words & Sentences (CDI:WS) is a widely used tool for assessing child vocabulary.
• Assessing vocabulary development can be lengthy, posing challenges in clinical and research settings.

Purpose of the Study:

• To investigate the feasibility and validity of an item response theory (IRT)-based computerized adaptive testing (CAT) version of the CDI:WS.
• To reduce the length of the CDI:WS while preserving its measurement precision.

Main Methods:

• Utilized parent-reported vocabulary data from 1,461 children (16-30 months) in the American CDI:WS norming sample.
• Applied the 2-parameter logistic IRT model to assess item fit.
• Simulated CDI-CAT versions with varying numbers of items (400, 200, 100, 50, 25, 10, 5).

Main Results:

• The 2-parameter logistic IRT model demonstrated good fit for most items.
• Simulations showed that CDI-CAT versions with at least 50 items accurately recovered full CDI scores (correlations > .95).
• CDI-CATs with 50+ items exhibited similar correlations with age and socioeconomic status as the full CDI:WS.

Conclusions:

• A CAT version of the CDI:WS is feasible and maintains measurement accuracy.
• The CDI-CAT has the potential to significantly reduce assessment length without compromising precision.
• This adaptive testing approach offers a more efficient method for evaluating early vocabulary development.