The effects of victimization are influenced by whether victims of sexual offenses declare themselves to be victims or are declared to be victims by others (e.g., in the case of sexually unenlightened children or young, sexually active juveniles). Empirical methods for research on sexual victimization include general surveys on sexual behavior and victimization, and retrospective studies of selected victims of sexual offenses. Retrospective studies must use random samples of the population, psychological testing if victims, and a detailed standard questionnaire. According to several studies, sexual offenses are most commonly reported by parents of the victim (60 percent) or by instutional representatives (15 percent). The question of whether sexual offenses cause damage to the victim has been controversial since the turn of the century. Research in this area has been hindered by the difficulty of putting together a sample, by lack of cooperation among specialists of different fields, and by the bias of court appointed psychological experts who always attempt to protect children. Most studies do not consider the latest developments in method and unquestioningly accept a simplistic causal explanation of the relationship between the sexual offense and neuroses. The sample used must be divided into damaged and undamaged individuals, taking into account temporary versus basic damage, other possible areas of damage, indirect effects of traumatic experiences, and effects in unreported cases. Attempts at listing and categorizing potential damages and their causes have made it clear that effects are complex and that damage is rarely attributable to a single event. Psychosocial damage from sexual offenses to victims under 21 years old is deemed most likely shortly after the offense, if the victim (usually female) resists, is relatively older, inexperienced, and from a sexually strict family environment. The offender's violence, a very small offender-victim age difference, great intensity of the sexual contact, and negative emotional reactions from the victim's environment are other factors likely to compound the extent of psychological damage. Notes, a bibliography of about 90 entries, and tables are furnished.