THROUGH THE USE OF THIS MANUAL, VOCATIONAL AGRICULTURE STUDENTS WITH OCCUPATIONAL INTEREST IN GRAIN FARMING AND CUSTOM COMBINE OPERATION MAY GAIN KNOWLEDGE ABOUT THE BASIC DESIGN AND OPERATION OF COMBINES. DEVELOPMENT BY A STATE CURRICULUM MATERIALS DIRECTOR INCLUDED CONSULTATION WITH ENGINEERS, TRIAL, AND REVISION. OBJECTIVES ARE STATED IN TERMS OF BEHAVIORAL OBJECTIVES AND BASED ON STUDENT NEEDS. FOUR UNITS OF INSTRUCTION ARE COVERED -- (1) WHAT IS THE VALUE OF DOING A GOOD JOB OF COMBINING, (2) BASIC DESIGN OF THE COMBINE, (3) OPERATION OF THE COMBINE, AND (4) ECONOMICS OF OWNING A COMBINE. THE MANUAL SUGGESTS TEACHING PROCEDURES AND STUDENT EXPERIENCES WHICH THE VOCATIONAL AGRICULTURE TEACHERS COULD CONDUCT IN THE CLASSROOM, THE AGRICULTURAL MECHANIC SHOP, AND ON FIELD TRIPS TO FARMS AND IMPLEMENT DEALERS. SINCE THE INDIVIDUAL FEATURES OF THE DIFFERENT MAKES AND MODELS OF COMBINES CANNOT BE INCLUDED IN ONE PUBLICATION, OPERATOR'S MANUALS FOR THE COMBINES BEING STUDIED SHOULD BE MADE AVAILABLE. A SET OF THIRTY 2- BY 2-INCH COLOR SLIDES WITH ACCOMPANYING SCRIPT, AND A TEST AND KEY FOR THE UNIT ARE AVAILABLE. THIS DOCUMENT IS AVAILABLE FOR $1.00 OR IN QUANTITY FOR 75 CENTS FROM OHIO VOCATIONAL AGRICULTURE, INSTRUCTIONAL MATERIALS SERVICE, THE OHIO STATE UNIVERSITY, 2120 FYFFE ROAD, COLUMBUS, OHIO 43210. (PA)