Table 3.
Summary of Constructs, Measurement Procedures, and Variables Used in Tests of Validity
| Constructs | Measures | Variables used in tests of validity | Role |
|---|---|---|---|
| Future spoken vocabulary | MB-CDI | Number of words child is reported to say on MB-CDI at Time 2a | Outcome |
| Concurrent spoken vocabulary | MB-CDI | Number of words child is reported to say on MB-CDI at Time 1a | Covariate |
| Indices of vocal development derived via automated vocal analysis | Two day-long LENA-DLP recorded samples | IVD score from one audio recording ACPU-C+V from two audio recordings AVA DA score from one audio recording Combined IVD and ACPU-C+V score from one audio recording | Predictors |
| Index of vocal development from conventional communication samples | CSBS-DP SSCS | Average of z-scores for: (a) proportion of communication acts including canonical syllables and (b) number of different consonants used communicatively across two samples | Predictor |
Note. CSBS-DP = Communication and Symbolic Behavior Scales-Developmental Profile Behavior Sample (CSBS-DP) [Wetherby & Prizant, 2002]; LENA-DLP = Language Environment Analysis—Digital Language Processor; MB-CDI = MacArthur Bates Communicative Development Inventory: Words and Gestures vocabulary checklist (Fenson et al., 2003); SSCS = semistructured communication sample with the examiner. IVD = Infraphonological Vocal Development. ACPU-C+V = Average Count Per Utterance of Consonants Plus Vowels. AVA DA = Automated Vocal Analysis Developmental Age. Time 2 was 4 months after indices of vocal development were collected.
MB-CDI scores were log10 transformed to correct severe positive skew.