The seven types of abuse, ranging from that involving inappropriate sexual behavior of staff on premises where children are present to complex multiple victim-perpetrator situations, is based on nine validation factors. These are number of perpetrators, number of victims, whether there are multiple incidents, the progression of abuse, explicit details of the abuse in the child's statements, the presence of secrecy, the use of coercion, behavioral or physical indicators of abuse, and whether or not pornography was involved. Factors which make the investigation of child sexual abuse in general and day care-related abuse in particular difficult to investigate are discussed, and general techniques for interviewing suspected child victims are described. For each type of sexual abuse, investigation protocols provide guidelines for preparation, initial investigation, validation, and continuing investigation. Protocols specify necessary interagency cooperation, possible witnesses to be interviewed, types of evidence to look for, documentation, and actions to be taken. Variables affecting differentiation of the types of abuse, such as frequency of contact and relationship of offender to center owner or director, also are discussed. 11 references.