Designed to measure the syntactic maturity of oral speech, the K-Ratio Index was devised for use in an investigation of the relationships between certain measures of syntactic maturity of oral languages and silent reading comprehension scores. Preparation for computing the ratio was accomplished by transcribing oral speech samples, excluding syntactically irrelevant matter, dividing into T-units, placing each T-unit at the top of its own data sheet, and counting the number of kernel structures imbedded in each T-unit. [This document is one of those reviewed in The Research Instruments Project (TRIP) monograph, "Measures for Research and Evaluation in the English Language Arts" to be published by the Committee of Research of the National Council of Teachers of English in cooperation with the ERIC Clearinghouse on Reading and Communication Skills. A TRIP review which precedes the document lists its category (Language Development), title, author, date, and age range (intermediate), and describes the instrument's purpose and physical characteristics.] (RB)