The study team collected data over a 3‐year period. The first year of data collection was 2003‐2004, prior to implementation of the CLIO curricula. The second and third years of data collection (2004‐2005 and 2005‐2006) corresponded to the two CLIO curricula implementation years.4
The study team conducted the following types of data collection in all CLIO projects: direct assessments of child language and literacy; teacher ratings of child social competence; videotapes of parent‐child interactions; interviews of parents; direct assessments of parent literacy; observations of classroom instruction in preschool, parenting education, and parent‐child classes; surveys of teachers and project directors; and tallies of child and parent participation in instructional services. The study team also observed and rated the fidelity of implementation of the CLIO curricula. The outcome constructs used in the CLIO impact analyses are presented in table ES-2.