This observer's manual is designed to familiarize people with the System for Integrated Language Communications Observation (SILCO), which rates the degree of integrated language communications instruction occurring in elementary classrooms during 40-minute time blocks. Sections of the manual discuss SILCO's development, organization, identification procedures, and ways to assure reliability. Five categories of the system are outlined, including how the language arts are integrated through the instructional organization of the classroom, the kinds of resources used for communication, the specific communication skills that are emphasized and developed, children's involvement in real life experiences, the involvement of two or more of the language arts (the integrative qualities) in student communication activities, teacher/student planning, classroom environment, teacher/student evaluation, and other content areas. Following detailed descriptions of the individual items on the SILCO form, instructions for recording and scoring the entries are discussed. (RL)