In such cases, corroborative evidence often is lacking Further, victims are less than ideal witnesses, both developmentally and psychologically. They may be unable to provide detailed spontaneous reports of the abuse, they may be frightened, their reports may be delayed, or they may be confused about dates and frequencies of events. Victims may fail to understand questions unless phrased in age-appropriate language, and they may retract earlier accusations if proceedings are protracted. For these reasons, expert testimony can help judge and jurors understand and evaluate the child victim-witness. Expert testimony can elucidate the characteristics of child sexual abuse victims, the veracity of child victims and the particular child, and the typical effects and symptons of victimization. It can provide information on the characteristics of abusers or incestuous families, thus helping to identify the defendant. Attempts to introduce expert testimony that the defendant has sexually abused the child has been held inadmissible by the courts, but in all other areas, courts have permitted such testimony. While courts have not been consistent about the admissibility of some types of expert testimony, all but the last type should be permitted. 242 footnotes.