IN PHASE 1, TWO COMPREHENSION MEASURES -- A PARAPHRASE MEASURE AND A TRUE-FALSE MEASURE -- WERE DEVELOPED. THE FIRST REQUIRES THE SUBJECT TO EXPLAIN THE MIRANDA STATEMENT IN HIS OWN WORDS; THE SECOND REQUIRES THE SUBJECT TO ANSWER QUESTIONS ABOUT THE STATEMENT. IN PHASE II, THE ABILITY OF 98 MALE JUVENILE DETAINEES TO UNDERSTAND TWO VERSIONS OF THE MIRANDA STATEMENT -- THE STANDARD WORDING AND A SIMPLIFIED VERSION DEVELOPED BY THE ST. LOUIS COUNTY JUVENILE COURT -- WAS ASSESSED BY BOTH MEASURES. NO SIGNIFICANT DIFFERENCES BETWEEN THE TWO WORDINGS WERE FOUND. IN PHASE III, THE EFFECTS OF INTELLIGENCE, AGE, RACE, SEX, AND NUMBER OF PREVIOUS COURT REFERRALS ON THE ABILITY OF 174 MALE AND FEMALE JUVENILE DETAINEES TO UNDERSTAND THE MIRANDA STATEMENT WERE TESTED BY BOTH MEASURES. INTELLIGENCE, AS MEASURED BY INTELLIGENCE QUOTIENT SCORE, WAS THE ONLY SINGLE VARIABLE SIGNIFICANTLY CORRELATED WITH COMPREHENSION ON BOTH MEASURES. IMPLICATIONS OF THE RESULTS ARE DISCUSSED. SUPPORTING DATA, COPIES OF STUDY INSTRUMENTS, AND A SELECTED BIBLIOGRAPHY ARE INCLUDED. (LKM)