AN INVESTIGATION WAS MADE ON THE RELATIONSHIP BETWEEN CONTRASTING ORGANIZATIONAL TYPES CREATED IN THE LABORATORY SETTING AND THE DISTRIBUTION OF THREE TYPES OF ROLE STRAINS--ROLE UNCERTAINTY, ROLE DISPARITY, AND ROLE INCOMPATIBILITY. THE TWO ORGANIZATION TYPES STUDIED DIFFERED IN DEGREE OF SPECIALIZATION, EMPHASIS ON RULES AND REGULATIONS, AMOUNT OF WORK PRESSURE, NUMBER OF FORMAL ADMINISTRATIVE LEVELS, CLARITY OF GOALS, DIFFERENTIALS IN INFLUENCE-AUTHORITY-POWER, AND AMOUNT OF INDIVIDUAL FREEDOM. INITIALLY, THE TWO LABORATORY WORK ORGANIZATIONS HAD IDENTICAL STRUCTURES, BUT AFTER A SPECIFIED TIME, ONE OF THE STRUCTURES WAS EXPERIMENTALLY CHANGED TO A CONTRASTING TYPE. EACH LABORATORY UNIT EMPLOYED 10 PERSONS, ONE OF WHOM WAS DESIGNATED AS THE UNIT SUPERVISOR. TWO WORK TEAMS WERE DEVELOPED WITHIN EACH OF THE TWO UNITS. THE LABORATORY EXPERIMENT LASTED FOR 20 WORKING DAYS. FOUR SOURCES OF DATA WERE USED--(1) QUESTIONNAIRES, (2) RECORDINGS MADE BY "NAIVE" OBSERVERS THROUGH A ONE-WAY MIRROR, (3) DAILY INTERVIEWS WITH PARTICIPANT OBSERVERS, AND (4) THE PROJECT DIRECTOR'S DAILY LOG OF HIS OBSERVATIONS. IT WAS HYPOTHESIZED THAT ROLE UNCERTAINTY AND ROLE DISPARITY WOULD BE MORE FREQUENT IN A RELATIVELY UNSTRUCTURED ORGANIZATION, WHILE ROLE INCOMPATIBILITY WOULD BE MORE FREQUENT IN A MORE HIGHLY STRUCTURED ORGANIZATION. SOME SUPPORT WAS FOUND FOR THESE HYPOTHESES. FURTHERMORE, IT WAS OBSERVED THAT EMPHASIS ON WORK RULES WAS MORE DIRECTLY ASSOCIATED WITH THE FREQUENCY OF ROLE INCOMPATIBILITY THAN ANY OTHER ORGANIZATIONAL FEATURE, AND THAT STRATIFICATION EMPHASIS AND TYPE OF SUPERVISION WERE CLOSELY RELATED TO THE APPEARANCE OF EACH ROLE STRAIN. THIS PAPER IS A REPRINT FROM "SOCIOLOGY AND SOCIAL RESEARCH," VOLUME 51, NUMBER 2, JANUARY 1967. (JH)