This tutorial attempts to provide a frank, step-by-step approach to Reed-Solomon (RS) error correction coding. RS encoding and RS decoding both with and without erasing code symbols are emphasized. There is no need to present rigorous proofs and extreme mathematical detail. Rather, the simple concepts of groups and fields, specifically Galois fields, are presented with a minimum of complexity. Before RS codes are presented, other block codes are presented as a technical introduction into coding. A primitive (15, 9) RS coding example is then completely developed from start to finish, demonstrating the encoding and decoding calculations and a derivation of the famous error-locator polynomial. The objective is to present practical information about Reed-Solomon coding in a manner such that it can be easily understood. Geisel, William A. Johnson Space Center 33086 NASA-TM-102162, S-605, NAS 1.15:102162 CODING; DECODING; ERROR ANALYSIS; FIELD THEORY (ALGEBRA); MAXIMUM LIKELIHOOD ESTIMATES; POLYNOMIALS; ERRORS; PROVING; SYMBOLS