Investigators also have considered longer-term associations between process quality and children’s developmental outcomes. A compilation of these studies can be found in Table 3. Included in the table are studies that considered relations between earlier child care experiences and later adjustment. To our knowledge, there are no published accounts that relate early child care quality to children’s adjustment beyond middle childhood. Table 3 presents information regarding sample size, controls for family factors, descriptions of the quality measures, descriptions of the child outcomes, and specific findings.
Findings on this issue have been reported by the NICHD Study of Early Child Care. Extensive information about the children, the families and child care was collected during home visits (1, 6, 15, 24, and 36 months), child care visits (6, 15, 24, and 36 months), and laboratory assessments (15, 24, and 36 months). Phone interviews were conducted every 3 months to track hours and types of child care. Children who were in nonmaternal care for more than 10 hours a week were observed in that care. The investigators (NICHD Early Child Care Research Network, 1998; 1999b; in press-b) asked if cumulative positive caregiving (the average of ORCE positive caregiving ratings collected during visits at each observation) is related to child developmental outcomes at 24 and 36 months. Mental development at 24 months was assessed in the laboratory with the Bayley. School readiness was measured using the Bracken School Readiness Scale, a scale that assesses knowledge of color, letter identification, number/counting, shapes, and comparisons. Expressive language skills and receptive language skills were measured at 36 months using the Reynell Developmental Language Scales. Mother and caregiver reports of child behavior problems were obtained using composite scores from the Child Behavior Checklist and the Adaptive Social Behavior Inventory. Peer skills were assessed during a videotaped semistructured play situation with a friend.
Relations between cumulative positive caregiving and child development were tested in analyses that controlled for child and family factors (child gender, maternal education, family income, maternal psychological adjustment, home quality assessed by Bradley and Caldwell’s HOME scale and videotaped observations of mother-child interaction) and other aspects of child care (time in center and total hours in care from 3 to 36 months). Table 6 summarizes findings from regression analyses and resultant partial rs that indicated effect sizes. As shown, the quality of child care during the first 3 years was related to children’s school readiness, expressive language, and receptive language at 3 years. Also shown on Table 6 are comparisons of children in high-quality and low-quality child care (defined with quartile splits), using the same covariates. This extreme group approach yielded d statistics. Effect sizes using this extreme group approach were significant for measures of school readiness, expressive language, and receptive language at 36 months.
In order to evaluate the magnitude of these findings, the NICHD investigators conducted parallel analyses that tested relations between quality of the home environment during the first 3 years and the child developmental outcomes (using the same covariates), and relations between child care hours during the first 3 years and child developmental outcomes (using the same covariates). Table 6 presents these effect sizes as well. Effects associated with quality of the home environment (the cumulative composite scores created from the Bradley and Caldwell HOME scale and mother-child interaction ratings) were roughly twice the size of the child care quality score. Effects associated with child care hours were substantially smaller than effects associated with child care quality. The NICHD investigators argued that these findings suggest effects of child care quality assessed longitudinally to age 3 years were neither huge nor trivial, but were large enough to be meaningful. It also should be noted that these effect sizes are likely to be a conservative estimate because of the selective participation by higher-quality settings. If the poorest quality child care settings refused to allow observations to be conducted, the range of quality scores would be truncated, resulting in smaller effect sizes.
Longer-term findings obtained from the Otitis Media Study (Burchinal, Roberts, Riggins, Zeisel, Neebe, and Bryant, in press) are consistent with those reported in the NICHD study. In that study, hierarchical linear models were tested. Observations of classroom quality obtained annually over a 3-year period were used to predict children’s adjustment up to age 3 years. Higher-quality child care over time was associated with better cognitive development, better receptive and expressive language skills, and better functional communication skills over time, controlling for child gender, family poverty status, and home environment quality.
A limitation with both of these reports is that children were studied only to age 3. Thus, it cannot be ascertained if early effects are harbingers of later differences or if these effects dissipate by the time that children enter grade school. As additional findings from these ongoing investigations become available, they can be used to identify conditions under which early child care quality differences are maintained or dissipate.
In the meantime, the Cost, Quality, and Outcomes Study has information that is relevant to this issue (Peisner-Feinberg et al., 1999). Started in 1993, observations were conducted in child care centers located in four states—California, Colorado, Connecticut, and North Carolina—that varied in licensing standards. Centers were evenly distributed in each state into nonprofit and for-profit programs. Within the eligible programs, 509 preschool classrooms and 224 infant/toddler classrooms were studied. Process quality was rated using the ECERS or ITERS, the Caregiver Interaction Scale (Arnett, 1989), and the Teacher Involvement Scale (Howes and Stewart, 1987). Quality indicators were combined into a single process quality composite.
A subsample of children was followed through 2 years of child care and the first 3 years of formal schooling (kindergarten through second grade). Children were assessed for receptive language skills, reading ability, and math skills. Child care and school teachers rated the children’s cognitive/attention skills, sociability, and problem behaviors each year. Longitudinal hierarchical linear models examined relations between the child care quality composite collected at age 4 (Time 1) and children’s developmental outcomes through grade 2. In all analyses, selection factors (maternal education, child’s gender and ethnicity) were controlled statistically.
Children who were enrolled in higher-quality child care classrooms as preschoolers were found to have better receptive language skills. Effect sizes for receptive language were moderate for the preschool period (.60 and .51 for the 2 years preceding school entry), more modest in kindergarten (.30), and not significant in second grade. Child care quality also was related to children’s math skills. Children who were enrolled in higher-quality child care had better math skills prior to school entry and during kindergarten and second grade, with modest effect sizes across the years (.20–.29). The relation was stronger for children whose mothers had less education. In further analyses that controlled for the quality of the elementary school classroom, the relations between child care quality and children’s math skills were maintained. It is notable that a similar finding was obtained in research conducted in Sweden. Broberg et al. (1997) found that process quality assessed using the Belsky and Walker checklist at 16, 28, and 40 months predicted better math skills at age 8, even after controlling for child and family factors.
Other research has considered longer-term associations between child care quality and children’s social-emotional outcomes. Howes (1990) focused on one particular aspect of process quality, child care socialization practices, in relation to children’s subsequent developmental outcomes. Caregivers’ involvement and investment in child compliance were measured during naturalistic observations in the child care setting. Having a more involved and invested caregiver during the first 3 years was associated with kindergarten teachers’ reports that the children had fewer behavior problems and better verbal IQs.
Alternative Views. As shown in Table 3, some investigators have not found relations between child care quality and later developmental outcomes. For example, Chin-Quee and Scarr (1994) did not find evidence of long-term effects in a longitudinal follow-up of the Bermuda study. In the initial study, concurrent associations were reported between process quality as measured by the ECERS and child developmental outcomes (McCartney, 1984; Phillips et al., 1987). In the follow-up study, teachers rated social competence (peer relations and cooperative behavior) and academic achievement for 97 of the original sample of 166, when children were in grades 1 and 2 (Time 2) and grades 3 and 4 (Time 3). Associations between the quality indicators during the preschool years and competence at school were tested with hierarchical regressions in which parental values, age of entry into care, and total amount of child care before school entry were controlled. Neither the global quality score nor the specific measures of caregiver language predicted children’s social competence and academic achievement at Time 2 or Time 3.
A longitudinal follow-up of children who participated in the Three-State Study also failed to detect long-term effects (Deater-Deckard, Pinkerton, and Scarr, 1996). In this project, assessments of child care quality were first obtained in 363 classrooms located in 120 centers in three states (Georgia, Virginia, Massachusetts) when 718 study children were infants, toddlers, and preschoolers. Process quality ratings were obtained by pulling items pertaining to teacher-child interaction from the ECERS and ITERS and the Assessment Profile (a process measure scored for presence or absence of specific items). Four years later, follow-up assessments were conducted for 141 of the original sample. Multiple regressions controlled for child (child adjustment at Time 1, age at Time 2, child gender) and family characteristics (SES, a composite of parenting stress and low emotional support, maternal endorsement of harsh discipline practices). The child care quality measure was a composite of the ITERS/ECERS, the Assessment Profile that measures physical facilities, caregiver training and education, and caregiver wages. In these analyses, the child care quality composite score at Time 1 did not predict changes in children’s behavior problems or social withdrawal at Time 2.
Although Scarr (1998) has argued that these studies demonstrate that child care quality has little or no long-term impact on children’s development, the findings must be interpreted with caution. Both studies are based on the assumption that a quality assessment obtained at one point in time is an adequate and accurate representation of child care quality. Single assessments might be sufficient if care arrangements and quality are stable; however, a single observation is not adequate if care is unstable or changing. In the Bermuda sample, Chin-Quee and Scarr (1994) reported that half the children experienced one, two, or three arrangements during the intervening period, and half experienced more than three arrangement changes. In the Three-State study, no information about child care quality in the intervening four years was collected. In both studies, it is difficult to interpret the meaning of the null findings in light of no information about child care quality across early childhood. Stronger, more valid tests of the effects of child care quality need to take into account cumulative quality and the pattern of quality over time.
The lack of long-term relations in the Three State Study may also reflect limitations in the assessment of process quality. Only moderate interobserver agreement was reported across the three research sites—.58 for the ECERS and .55 for the ITERS (McCartney et al., 1997). Lower relations between process quality and child outcomes would be expected when process quality scores are less reliable.
"report.pdf" (pdf, 132.7Kb)
"table1.pdf" (pdf, 43.75Kb)
"table2.pdf" (pdf, 43.32Kb)