The National Institute of Child Health and Human Development (NICHD) Study of Early Child Care is an ongoing, prospective, 3-year longitudinal study of over 1,300 full-term healthy infants and families from 10 sites across the United States. While the sample is not nationally representative, the subjects come from major regions of the country: the East Coast, the West Coast, the Mid-West, the North, and the South. They come from urban and from rural settings, and include minorities as well as single-parent and two-parent families. The study examines the concurrent, long-term, and cumulative influences of variations in early child care experiences on the cognitive, linguistic, social, emotional, and physical development of infants and toddlers. The study design takes into account the complex interactions among characteristics of the family and home, of the child care environments, and of the child. Subject recruitment started in January 1991, and data collection was scheduled to end at the beginning of 1995. Data collection involved periodic telephone calls to families beginning at 3 months and home visits, child care center visits, or laboratory assessments at 1, 6, 15, 24, and 36 months. This document is volume 5 of a 5-volume operations manual that explains, in 29 chapters, the procedures used in conducting the NICHD study. Volume 5 consists of chapters 25 through 29. Chapter 25 provides instructions for conducting follow-up telephone interviews at 35 months. Subsequent chapters address the 36-month visits and laboratory assessments. Chapter 26 presents an overview of the visits to the child's home and child care center, and laboratory assessments. Chapter 27 provides instructions for conducting the visit to the child care center. Instructions for conducting the 36-month home visit are given in chapter 28, which also includes specific instructions for administering the Bracken Basic Concept Scale and a home inventory, information about conducting standardized interviews and questionnaires, and instructions for gathering data on ear infections. Chapter 29 provides instructions for: (1) conducting the 36-month laboratory assessment; (2) observing children's solitary play and clean-up activities; (3) conducting a modified Strange Situation procedure; (4) administering and coding the Reynell Developmental Language Scales; (5) measuring children's self-control; (6) assessing the quality of mother-child interaction; (7) administering the Peabody Picture Vocabulary Test; (8) assessing children's television viewing habits; (9) assessing children's behavioral and emotional problems; and (10) measuring children's physical growth. (BC)