Latent structure path analytic methods are to be used to construct and test models for development of children who, as infants, were treated in models represent some aspects of medical and parental conditions at the time of the child's birth, and similar conditions plus measures of the child's behavior 6-months, 15-months, 4-years, and 7-years later. At the younger ages the sample sizes are approximately 900; at the older ages samples of 237 and 197 are available for repeated-measures analyses. Measures of the child's behavior pertain to body control and coordination, fine muscle skills and intellectual abilities of several kinds. Analyses are to be directed at showing how medical and parental conditions at an early age, as well as emerging indicants of the child's characteristics, are interrelated and related to the child's behavior at older ages, particularly indications of the kinds of competencies that are important for early school accomplishments. Theories about child-parent transactions will be used to help guide some of the analyses. One set of analyses will be focused on identifying patterns within separate classifications of variables and, second, relating the patterns of different classifications. A second set of analyses will be focused on identifying patterns of covariation across separate categories of variables. In each case randomly selected parts of the data will be set aside for checking analyses designed to indicte the sampling stability of any patterns that are found. One important purpose of the research is to fully describe infant-to-child development. The major result of the research should be an improved empirical basis for building theories about child development, but other values, such as ideas about modeling, can also emerge from the study. Results from the study can have important practical applications.