The ISI assigns stress level ratings to specified events under the categories of Investigation, Adjudication, Testimony, and Protective Services (e.g., testimony in criminal court equals 111 stress points), based on information from 98 child sexual abuse professionals. Items are added as applicable to individual cases. Modifying factors (e.g., the perpetrator being present) increase or decrease the number of stress points. The scale was used in interviews with 254 sexually abused children aged 4 to 17 and their parents in four sites--Erie County (Buffalo), NY; Polk County (Des Moines), IA; Ramsey County (St. Paul), MN; and San Diego County, CA--at the time their cases were reported, and again 9 months later. Higher scores were expected for older children (because they may have suffered longer periods of abuse) and those who had suffered more severe abuse. Site differences were expected as follows, according to different procedural emphases: In Polk County, lower Adjudication and Testimony scores, and higher Protective Services scores; in Ramsey County, high Investigation scores; in San Diego and Erie Counties, high Adjudication and Testimony scores. The results showed these expected pattern variances, thus supported validity of ISI. Further, over the course of a year, ISI scores declined as jurisdictions actively sought to reduce the intrusiveness of intervention. 3 tables, 16 references