AGA	Appropriate for Gestational Age
ASD	Autism Spectrum Disorder
DCD	Developmental Coordination Disorder
ESCS	Early Social Communication Scales
IBR	Initiating Behavioral Request
IBRH	Initiating Behavioral Request—High Level
IBRL	Initiating Behavioral Request—Low Level
ICC	Intraclass Correlation Coefficient
IJA	Initiating Joint Attention
IJAH	Initiating Joint Attention—High Level
IJAL	Initiating Joint Attention—Low Level
LMM	Linear Mixed-Effects model
RBR	Responding to Behavioral Request
RJA	Responding to Joint Attention
RJAD	Responding to Joint Attention—Distal
RJAP	Responding to Joint Attention—Proximal
SLI	Specific Language Impairment