Table 3.
Predictor constructs, procedures, untransformed component variable, and analyzed variable
| Construct | Procedures/periods | Untransformed component variables | Analyzed variable |
|---|---|---|---|
| Estimated receptive vocabulary | CSBS @ all periods | Comprehension subscale (16) score | Log 10-transformed ordinary least squares Time 1-centered intercept of the growth curve for receptive vocabulary aggregate |
| MCDI @ all periods | Number of words understood only + number of words said | ||
| Parent-reported receptive vocabulary | MCDI @ T1 | Number of words understood only + number of words said | Log 10-transformed sum |
| Play | CSBS @ T1 | 1st object use subscale (17) score | Average of z score |
| DPA @ T1 | Number of unique action schema | ||
| Responding to joint attention (RJA) | CSBS @ T1 | RJA subscale (3) score | Square root-transformed average z score |
| ESCS @ T2 | Number of correct responses to eight presses | ||
| Intentional communication | UCS @ T1 | Number of intentional communication act | Square root-transformed average z score |
| ESCS @ T2 | Number of communication acts summed across pragmatic functions | ||
| Attention during child-directed speech (CDS) | ACDS @ T1 | % of the total time that CDS “vignettes” were presented that the child was looking to the presentation window | Untransformed score |
| Motor imitation | MIS @ T1 | Total raw score | Log 10-transformed average z score |
| OME @ T1 | Oral motor imitation subscale raw score | ||
| Parent linguistic responses to child leads | PCFP @ T2 | Number of 5-s intervals with child’s attentional lead followed by adult utterance talking about child’s referent | Average z score |
| PCS @ T2 | Number of 5-s intervals with child attention or communication lead followed by adult utterance talking about child’s referent | ||
| Nonimitative oral motor functioning | OME @ T1 | Eating behavior subscale raw score | Reflected log 10-transformed score |
| Consonant inventory in communication acts | CSBS @ T1 | Consonant subscale (11) score | Untransformed scale score |
| Cognitive impairment | MSEL except gross motor scale @ T1 | Average age equivalency across subscales/chronological age | Untransformed developmental ratio |
| Autism symptomotology | ADOS module I @ T1 | Diagnostic algorithm score | Reflected log 10-transformed score |
CSBS Communication and Symbolic Behavior Scales-Developmental Profile Behavior Sample, MCDI McArthur-Bates Communication Development Inventory, DPA Developmental Play Assessment, ESCS Early Social Communication Scales, UCS Unstructured communication sample with examiner, ACDS attention during child directed speech procedure, MIS Motor Imitation Scale, OME Oral Motor Examination, PCFP parent–child free play, PCS parent–child snack, MSEL Mullen Scale of Early Learning, ADOS Autism Diagnostic Observation Scales