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 2 of a 5-volume operations manual that explains, in 29 chapters, the procedures used in conducting the NICHD study. Volume 2 consists of chapters 8 through 12. Chapter 8 provides instructions for conducting the follow-up telephone interview at 5 months. Subsequent chapters address the six-month visits and assessments. Chapter 9 includes: (1) general instructions for conducting the 6-month home visit; (2) information on standardized interviews and questionnaires; (3) instructions on conducting an inventory of the home environment; and (4) procedures for videotaping mother-infant interactions. Chapter 10 discusses the procedure for visiting subject children's child care centers and provides instructions on conducting an infant-toddler version of a home environment inventory. The procedure for conducting a visit with the father is outlined in chapter 11. Chapter 12 contains instructions for conducting and coding an interview intended to assess the mother's daily activities. (BC)