The research used a two-by-two factorial design to address the effects of two manipulations. The first experimental condition involved administering the standard DUF informed consent or an enhanced consent that told the arrestees more abut the confidential nature of the research and the capabilities of the urinalysis. The second condition involved collecting the urine specimen before or after the interview was conducted. The researcher approached 2,009 arrestees in the Cleveland, Detroit, and Houston DUF sites to participate in the study. They were randomly assigned to one of the four experimental cells. Results revealed that none of the experimental conditions affected the interview and urine response rates. In addition, whether an arrestee received the standard or enhanced informed consent did not affect self-reports of drug use. Moreover, while some comparisons indicated that the urine-first condition raised the rates of self-reporting, these differences did not occur in more than one site. Recommendations focus on the apparent robustness of arrestee cooperation rates, the advisability of using a succinct informed consent, and the potential usefulness of asking for the urine specimen before conducting the interview. Figure, tables, appended study scripts and letter, and 4 references