Primary Outcomes (end points)
Various instruments are used to assess different dimensions of child development. Linear models, hierarchical linear modeling, and classroom random effect models are used to estimate impact and the role of moderators. We use instruments that evaluate children’s emotional, social and cognitive development over time. We also measure family characteristics, program costs (direct and indirect) and program quality.
Instruments vary with children’s age, as cohorts progress through pre-k, kindergarten and into primary. We assess children’s early cognition and motor skills, receptive vocabulary, emergent literacy, early math skills, and socio-behavioral abilities and schooling outcomes each academic year. We assess these specific abilities to observe the effects of treatment on brain development and cognitive capacities that emerge as various areas of the brain mature. Assessing specific abilities allows inferences concerning the periods of development and specific brain areas that are vulnerable, and may shed light on the biological and psychological mechanisms through which interventions affect child development. Specific instruments and indicators used are:
i. Family Background and Home Environment questionnaires: Parents questionnaires collect information on parental ethnicity, parental income, savings, education, employment, welfare, family composition, immunization living conditions, parenting practices and information on the early childhood experiences.
ii. Infant Development: The Bayley Scales of Infant Development (BSID) are the most commonly used assessment of infant development (Fernald, Kariger, Engle & Raikes, 2009; Bayley, 2005). The Bayley has shown to predict later non-verbal and verbal cognition, i.e. as measured by the Test de Vocabulario en Imágenes Peabody (TVIP) (Blaga, Shaddy, Anderson, Kannass, Little & Colombo, 2009). As children grow, we measure child development using the Vineland Adaptive Behavior Scales (Sparrow, Balla, & Cicchetti, 1985). The Vineland is an individual parent questionnaire that assesses personal and social skills in communication, daily living skills, socialization, and motor skills.
iii. Language: The Test de Vocabulario en Imágenes Peabody (TVIP) (Dunn, Padilla, Lugo and Dunn, 1986) uses 125 items to assess receptive vocabulary of Spanish-speaking students. The TVIP has been used extensively in preschool studies (Early, Maxwell, Burchinal, Alva, Bender, Bryant, et al., 2007).
iv. Math and Literacy: The Woodcock-Muñoz III Tests of Achievement (WM-III) The WM-III is a comprehensive set of individually administered tests of children’s early literacy and mathematical skills and knowledge, and we use subtests #1, #9 and #10, letter-word identification, text comprehension and applied problems, respectively (Muñoz-Sandoval, Woodcock, McGrew & Mather, 2005). In addition, in the first waves the Early Literacy Skills Assessment (ELSA) (DeBruin-Parecki, 2005) measures four key elements of early literacy development– comprehension, phonological awareness, alphabetic principle, and concepts about print.
v. Socio-emotional Development: The Ages and Stages Questionnaires for the Socio-Emotional domain (ASQ: SE) (Squires, Bricker and Twombly, 2009) is a parent-completed assessment for children ages 6-60 months on socio-emotional development. The ASQ has been used for early development assessments in low and middle income countries (Handal, Lozoff, Breilh and Harlow, 2007; Tsai, McClelland, Pratt & Squires, 2006). As children grow older, we switch to the Behavior Assessment System for Children (BASC-II), which measures adaptive and problem behaviors (Bracken, Keith, & Walker, 1998; Doyle, Ostrander, Skare, Crosby & August, 1997) and the Strengths and Difficulties Questionnaire (Goodman, 1997).
vi. Executive Function: Head-Toes-Knees and Shoulders: The HTKS examines behavioral regulation (Ponitz, McClelland, Matthews & Morrison, 2009; Ponitz, McClelland, Jewkes, Conner, Farris & Morrison, 2008) in children’s early years. HTKS requires children to remember and respond to behavioral commands. It has predictive validity with achievement and teacher-ratings of self-regulation. In addition, after the third wave we incorporate the following set of instruments, in order to have a stronger and more comprehensive battery for this dimension: Peg Tapping Task (Diamond and Taylor, 1996); Dimensional Change Card Sort (Zelazo, 2006) and Copy Design (Osborne, Butler and Morris, 1984).
vii. Children’s health status: In line with similar international studies (Fernand, Gertler & Neufeld, 2008; Overholt, Sellers, Mora, Paredes & Herrera, 1982; Walker, Wachs, Meeks Gardner, et al., 2004) we collect information on height and weight, BMI and arm circumference once a year following World Health Organization (WHO) standards.