Developed was a diagrammatic model of basic physical science content structure which included substantive components common to physics and chemistry selected from the Physical Science Study Committee (PSSC) physics and the Chemical Education Materials Study (CHEMS) chemistry texts. A descriptive rationale for the model was written which gave a progression of content from simple to complex. Judges in physics and chemistry were consulted and the model was revised on the basis of judges' comments and suggestions. (GR)