Psychometric properties of FVMC (Guo et al., 2019)

Purpose: The purpose of this study was to provide reference data and evaluate the psychometric properties for the finite verb morphology composite (FVMC) measure in children between 4 and 9 years of age from the database of the Edmonton Narrative Norms Instrument (ENNI; Schneider, Dubé, & Hayward, 2005).
Method: Participants included 377 children between age 4 and age 9, including 300 children with typical language and 77 children with language impairment (LI). Narrative samples were collected using a story generation task. FVMC scores were computed from the samples. Split-half reliability, concurrent criterion validity, and diagnostic accuracy for FVMC were further evaluated.
Results: Children's performance on FVMC increased significantly between age 4 and age 9 in the typical language and LI groups. Moreover, the correlation coefficients for the split-half reliability and concurrent criterion validity of FVMC were medium to large (rs ≥ .429, ps < .001) at each age level. The diagnostic accuracy of FVMC was good or acceptable from age 4 to age 7, but it dropped to a poor level at age 8 and age 9.
Conclusion: With the empirical evidence, FVMC is appropriate for identifying children with LI between age 4 and age 7. The reference data of FVMC could also be used for monitoring treatment progress.

Supplemental Material S1. Description of the stories in the ENNI protocol.

Supplemental Material S2. Computation of the finite verb morphology composite (FVMC).

Supplemental Material S3. Example of a receiver operating characteristic (ROC) curve analysis.

Supplemental Material S4. F values, p values, and effect sizes (d) for the group differences in total number of C-units, mean length of C-units in morphemes (MLCUm), number of different words (NDW), and number of obligatory contexts for the FVMC analysis (# of OC for FVMC) by age.

Supplemental Material S5. Z score and confidence interval calculation table for FVMC.

Guo, L.-Y., Eisenberg, S., Schneider, P., & Spencer, L. (2019). Finite verb morphology composite between age 4 and age 9 for the Edmonton Narrative Norms Instrument: Reference data and psychometric properties. Language, Speech, and Hearing Services in Schools. Advance online publication. https://doi.org/10.1044/2019_LSHSS-19-0028