THE PRIMARY PURPOSE OF THIS DISSERTATION IS TO DEVELOP A STRUCTURAL THEORY, ALONG FACET-THEORETIC LINES, FOR THE PERCEPTION OF MORSE CODE SIGNALS AND RELATED RHYTHMIC PATTERNS. AS STEPS IN THE DEVELOPMENT OF THIS THEORY, MODELS FOR TWO SETS OF SIGNALS ARE PROPOSED AND TESTED. THE FIRST MODEL IS FOR A SET COMPRISED OF ALL SIGNALS OF THE INTERNATIONAL MORSE CODE (IMC) IN ADDITION TO SOME SIMILAR DOT AND DASH PATTERNS. THE SECOND MODEL IS FOR A SET COMPRISED OF 32 MORSE-LIKE RHYTHMIC PATTERNS IN WHICH THE SILENT INTERVALS BETWEEN THE DOTS AND DASHES CAN BE EITHER SHORT OR LONG. AN EXPERIMENT BY ROTHKOPF SUPPLIES THE DATA USED TO TEST THE FIRST MODEL. AN EXPERIMENT CARRIED OUT BY THE PRESENT INVESTIGATOR PROVIDED THE DATA USED TO TEST THE SECOND MODEL. IN ROTHKOPF'S STUDY 598 AIRMEN (WHO HAD HAD NO PREVIOUS MORSE CODE TRAINING) AWAITING BASIC TRAINING WERE PRESENTED PAIRS OF IMC SIGNALS AND WERE INSTRUCTED TO RESPOND "SAME" OR "DIFFERENT" ON AN IBM ANSWER SHEET TO EACH OF THESE PAIRS ACCORDING TO WHETHER THEY PERCEIVED THE TWO SIGNALS OF THE PAIR TO BE THE SAME OR DIFFERENT. IN THE PRESENT INVESTIGATOR'S EXPERIMENT, 324 FEMALE UNDERGRADUATES AT THE UNIVERSITY OF MICHIGAN ENROLLED IN INTRODUCTORY PSYCHOLOGY COURSES WERE PRESENTED PAIRS OF THE MORSE-LIKE RHYTHMIC PATTERNS, RATHER THAN PAIRS OF IMC SIGNALS, AND WERE INSTRUCTED TO INDICATE WHETHER THEY PERCEIVED THE SIGNALS OF EACH OF THESE PAIRS AS SAME OR DIFFERENT. IN TESTING BOTH MODELS THE PERCENTAGE OF "SAME" RESPONSES TO EACH ORDERED PAIR OF SIGNALS IS USED AS A MEASURE OF THE CONFUSABILITY OF THE SIGNALS OF THE ORDERED PAIR. USING THIS CONFUSABILITY MEASURE, THE FIRST AND SECOND MODELS ARE SHOWN TO BE OVERWHELMINGLY SUPPORTED BY THE DATA. OTHER PATTERNS OF SIGNAL CONFUSION IN THE TWO EXPERIMENTS ARE ALSO DESCRIBED. THIS DISSERTATION APPEARS IN "STUDIES IN LANGUAGE AND LANGUAGE BEHAVIOR, PROGRESS REPORT IV," PUBLISHED BY THE CENTER FOR RESEARCH ON LANGUAGE AND LANGUAGE BEHAVIOR, 220 EAST HURON STREET, ANN ARBOR, MICHIGAN 48108. CHAPTER V, WHICH COMPRISES THE SUMMARY IS NOT INCLUDED. IT IS AVAILABLE ON REQUEST FROM THE AUTHOR AT THE ABOVE ADDRESS. (AUTHOR/AMM)