Abstract : This report documents results of a 12-month R/D effort consisting in development of MATRES III, a language understanding system for automated generation of AIS data base elements. Section 1.0 discusses the need for a high-volume message processing technology in the I/W environment, and summarizes its current state of the art exemplified in MATRES II. Section 2.0 describes in detail the methodological approach adopted in MATRES III for analysis/description of event reports, and provides background information on conceptually relevant efforts. Section 3.0 provides an overview of message processing from raw text input to final output of event record in MATRES III. Section 4.0 presents MATRES III model data based system, and Section 5.0 provides guidelines for continuing development of message processing technology. Examples of message segments and event records synthesized from these segments are presented in Appendices A and B, respectively. (Author)