A second approach to describing child care quality is in terms of their structural and caregiver characteristics. Characteristics such as child:adult ratio, group class size, caregiver formal education, and caregiver specialized training are viewed as more distal contributors to quality environments. Structural and caregiver characteristics are the only quality indicators obtained in survey studies such as the National Child Care Survey (Hofferth, Brayfield, Deich, and Holcomb, 1991), the National Household Education Survey (Hofferth et al., 1998), and the National Longitudinal Survey of Youth (Blau, 1999-c). Structural and caregiver characteristics have been collected in addition to process-oriented measures in studies such as the Cost, Quality and Outcome Study, thereby permitting relations between these characteristics and process quality to be evaluated.
Relations between structural and caregiver characteristics and process quality are well-documented in the research literature. Table 1 is a compilation of the studies conducted in the United States that have considered this issue. The table includes information regarding sample size, type of care setting, the structural and caregiver characteristics that were measured, the process quality measures that were collected, and findings that were obtained. As indicated in Table 1, some studies have considered bivariate relations between structural and caregiver characteristics, and process quality using Pearson correlations and t-tests. Other studies (Blau, in press; NICHD Early Child Care Research Network, 1996, in press-a; Phillipsen, Burchinal, Howes, and Cryer, 1997) utilized multiple regression techniques in an effort to isolate the relative impact of different characteristics. As documented on the table, the multivariate results are consistent with the bivariate and global composite analyses. As is evident in Table 1, studies have considered both global composites of structural and caregiver characteristics and individual factors in relation to process quality (Howes, 1990; Vandell and Powers, 1983).
When child:adult ratios are lower, caregivers spend less time managing children in their classrooms and children appear less apathetic and distressed (Ruopp, Travers, Glantz, and Coelen, 1979). When child:adult ratios are lower, caregivers offer more stimulating, responsive, warm, and supportive care (Clarke-Stewart, Gruber, and Fitzgerald, 1994; Howes, 1983; NICHD Early Child Care Research Network, 1996, in press-a; Phillipsen et al., 1997; Volling and Feagans, 1995). Ratios also are associated with global process quality scores (Burchinal, Roberts, Nabors, and Bryant, 1996; Howes, Phillips, and Whitebook, 1992; McCartney, et al., 1997; Scarr, Eisenberg, and Deater-Deckard, 1994; Whitebook, Howes, and Phillips, 1990). For example, in a study of 414 children who resided in three states, Howes et al. (1992) determined that “good” and “very good” scores on the ITERS and ECERS were more likely in infant classrooms with ratios of 3:1 or less, in toddler classrooms with ratios of 4:1 or less, and in preschool classrooms with ratios of 9:1 or less. More than half of the infant classrooms with ratios higher than 4:1 and preschool classrooms with ratios higher than 5:1 received scores that were categorized as “inadequate.”
Group size also has been considered in relation to process quality. In simultaneous multiple regressions that included group size, ratio, caregiver education, and caregiver specialized training, the NICHD Study of Early Child Care (1996; in press-a) determined group size to be uniquely associated with positive caregiving. Similarly, Ruopp et al. (1979) reported group size to predict caregiver behavior even when child:adult ratio was controlled. In these studies, caregivers were more responsive, socially stimulating, and less restrictive when there were fewer children in their classrooms. These relations also are observed in child-care homes (Elicker, Fortner-Wood, and Noppe, 1999; Stith and Davis, 1984).
Caregivers’ formal education and specialized training also are related to quality of care. Caregivers who have more formal education (NICHD Early Child Care Research Network, 1996; Phillipsen et al., 1997) and more specialized training pertaining to children (Arnett, 1989; Berk, 1985; Howes, 1983, 1997) offer care that is more stimulating, warm, and supportive. Highly educated and specially trained caregivers also are more likely to organize materials and activities into more age-appropriate environments for children (NICHD Early Child Care Research Network, 1996). These settings are more likely to receive higher scores on the global quality scales such as the ECERS, ITERS, ORCE, and CC-HOME (Clarke-Stewart, et al., 2000; Howes and Smith, 1995; NICHD Early Child Care Research Network, 1996, in press-a).
Repeated-measure analyses conducted for children in the NICHD Study of Early Child Care at 15, 24, and 36 months ascertained that group size and child:adult ratios were stronger predictors of process quality for infants, whereas caregiver educational background and training were stronger predictors of process quality for preschoolers (NICHD Study of Early Child Care, in press-a). These relations do not appear to be an artifact of restricted ranges. The standard deviations for caregiver formal education and caregiving training were similar at different assessment points. Standard deviations for ratio and group size increased for older children. The differential patterns, then, suggest the merits of an age-related strategy for improving process quality. Ratios and group size may be more critical for infant care; caregiver training and education may be more critical for preschoolers.
Caregiver wages is another factor associated with process quality (Howes, Phillips, and Whitebook, 1992; Scarr et al., 1994). See Table 1. In the Three-State Study, Scarr et al. reported teacher wages to be the single best predictor of process quality. In analyses of the Cost, Quality, and Outcome data set, Phillipsen et al. (1997) determined lead teachers wages to significantly predict scores on the ECERS and the Arnett sensitivity scales.
Although much of the research literature has reported significant relations between structural and caregiver characteristics, and process quality, Blau (in press) has cautioned that these associations may be the result of uncontrolled factors that are confounded with the structural and caregiver characteristics. He argues that these confounding factors might include center policies, curriculum, and directors’ leadership skills. To address this perceived shortcoming, Blau conducted secondary analyses on 274 child care centers that were part of the Cost, Quality, and Outcomes Study. In his first set of analyses, Blau conducted regressions to determine if individual structural and caregiver characteristics were associated with process quality when other factors (teacher, family, center characteristics) were controlled. His findings were consistent with other reports. When child:adult ratios were larger, ITERS and ECERS scores were lower. When caregivers had attended college or training workshops and when caregivers had college degrees in fields related to child care, ECERS scores were higher.
Blau then tested relations between structural-regulable characteristics and process quality using a more stringent fixed-effects model that included center as a control variable. This fixed-effects approach was possible because two classrooms were typically observed in each center. In centers in which there were both infants and preschoolers, one classroom of each type was observed. In centers serving only preschoolers, two preschool classrooms were selected randomly. When center was controlled along with type of classroom (infant vs. preschool), relations between structural and caregiver features and process quality were reduced. Blau interprets this reduction to mean that unobserved center characteristics account for the previously reported relations between structural factors and process quality. Our concern, however, is that the center fixed-effect control is inappropriate. As Blau himself noted, this approach requires within-center variability in the structural characteristics. It is unlikely that classrooms in the same center are highly variable in terms of caregiver training, ratio, or group size, especially given that the model also controlled for type of classroom (infant/toddler vs. preschool). The inclusion of the specific center as a control variable resulted in an underestimation of effects.