This study was undertaken to determine the degree of agreement between science textbooks and scholars in earth science relative to earth science concepts to be included in the K-12 science curriculum. The study consisted of two phases: (1) the identification of a sample of earth science concepts rated by earth scientists as important for inclusion in the K-12 science curriculum and (2) the determination of whether or not these concepts are included in science textbooks currently used in grades K-12. A final list of 52 concepts was selected by three panels composed of university faculty earth scientists and earth science scholars selected at random from five professional organizations. Five textbooks were chosen by random selection for concept evaluation from each of these categories of textbooks: elementary science series, general science textbook series, physical science textbooks, and earth science textbooks. The results indicate that: there is general agreement among the scholars as to what earth science concepts should be included in grades K-12; it is probable that a majority of the 52 concepts would be found in a given general science series alone, or in earth science text alone, or a combination of a given elementary science textbook series with either, or a combination of all three; the ten concepts concerned with man's relationship to his environment were considered important by the scholars but were seldom rated as present in the textbooks analyzed. (Author/PR)