TABLE 1.

Components of the Primary and Moderating Composite Dependent Variables

Composite DV	Component variables
Autism symptom severity
	ADOS-2a calibrated severity score
	PDDB-Ib expressive receptive social communication composite reflected raw score
Expressive communication
	15-min Communication sample; wficc
	15-min Communication sample; number of different word roots
	MSELd expressive language age equivalency
	VABS-2e expressive communication age equivalency
	MB-CDIf expressive raw score
	PDDB-I expressive social communication abilities composite raw score PDDB-I expressive language raw score
Nonverbal abilities
	MSEL fine motor age equivalency
	MSEL visual reception age equivalency
	VABS-2 daily living skills age equivalency
	VABS-2 motor skills age equivalency
	VABS-2 socialization age equivalency
Receptive language
	MSEL receptive language age equivalency
DQ	VABS-2 receptive language age equivalency
	MSEL expressive language age equivalency
	MSEL receptive language age equivalency
	MSEL fine motor age equivalency
	MSEL visual reception age equivalency

Note: ADOS-2 = Autism Diagnostic Observation Schedule, Second Edition; DQ = developmental quotients; DV = dependent variable; MB-CDI = MacArthur—Bates Communicative Development Inventories; MSEL = Mullen Scales of Early Learning; PDD = pervasive developmental disorder; PDDB-I = PDD Behavior Inventory; VABS-2 = Vineland Adaptive Behavior Scales, Second Edition; wfic = weighted frequency of intentional communication.

^aAutism Diagnostic Observational Schedule version 2

^bPervasive Developmental Disorders Behavior Inventory—parent rating form.

^cWeighted frequency of intentional communication.

^dMullen Early Learning Scales.

^eVineland Adaptive Behavior Scales version 2.

^fMacArthur—Bates Communicative Development Inventory, combined infant and toddler forms.