Does Quality of Child Care Have Meaningful Effects on Children’s Developmental Outcomes?
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 installment loans New York 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.
Health and Safety Indicators of Quality
Global process quality measures such as the ECERS, CC-HOME, and Profile Assessment include health and safety indicators as a component of process quality. Research conducted in the medical and public health arenas has focused more exclusively on these indicators in relation to children’s physical health and safety. More hygienic practices by staff and children (Niffenegger, 1997; St. Sauver, Khurana, Kao, and Foxman, 1998) are associated with fewer respiratory illnesses and other infectious diseases. These practices include frequent handwashing after diapering, before meals, and after nose wiping. Child injuries in child care settings are most likely to occur on playgrounds and are most due to falls from climbing equipment (Briss, Sacks, Addis, Kresnow, and O’Neil, 1995; Browning, Runyon, and Kotch, 1996). Height of the equipment and lack of an impact-absorbing surface under the equipment have been consistently identified as the factors most highly associated with injuries that required medical treatment. The North Carolina Smart Start initiative was successful in improving the safety of child care centers with playground improvement grants (Kotch and Guthrie, 1998).
The weight of the research evidence demonstrates significant relationships between process quality, structural and caregiver characteristics, and health and safety practices. The next section uses process, structural, and caregiver measures to predict developmental outcomes for children.
There are substantial challenges for researchers and policy makers who seek to answer questions about the effects of child care quality on children’s development. One well-acknowledged difficulty is the absence of well-controlled experiments in which children are randomly assigned to child care that varies in quality. Instead, investigators have studied children whose families and child care settings are willing to participate. This examination of naturally occurring child care, as opposed to more controlled experiments, poses challenges for researchers and policy makers (Blau, 1999c; Lamb, 1998; NICHD Early Child Care Research Network, 1994; Vandell and Corasaniti, 1990). These challenges are related to family/child selection biases and to restricted variability in quality scores. Before reviewing research findings pertaining to effects of quality, we briefly describe common strategies for addressing these research challenges.
Family/Child Selection Biases. The possibility that families differ in their child care choices is a topic of interest in its own right (NICHD Early Child Care Research Network, 1997; Singer, Fuller, Keiley, and Wolf, 1998). It also is a critical issue for investigators who are interested in ascertaining the effects of child care on children (Howes and Olenick, 1986; Vandell, 1997). The problem is that ostensible “effects” of child care quality ily characteristics that are confounded with child care quality. As a result of this concern, it has become standard practice for researchers to incorporate family selection factors into their analyses. As is evident in Tables 2 and 3, almost all studies conducted in recent years have included controls for family characteristics.