The preparation of spelling skills indices, which may be used to describe the spelling content commonly taught in textbooks and the performance modes used to practice this content, is outlined in this paper. Separate sections discuss the preliminary analysis that was performed; the establishment of a Content Index that specifies major categories and subcategories of spelling content; the derivation of a Performance Mode Index to describe performance modes appearing in textbook exercises; the coding of the instructional exercises in eight commercial spelling series; and the computer-assisted development of a list of all spelling words taught. Appendixes present the Content and Performance Mode Indexes, a list of the spelling series used for coding, and a sample page of the computer printout of spelling vocabulary. (GT)