The National Assessment of Educational Progress' (NAEP) 1992 reading assessment was administered to nationally representative samples of fourth-, eighth-, and twelfth-grade students attending public and private schools, and to state representative public-school samples of fourth graders in 43 jurisdictions. Nearly 140,000 students were assessed in all. Data were summarized on the NAEP reading proficiency scale ranging from 0 to 500, and results were reported according to three achievement levels at each grade--basic, proficient, and advanced. Major findings were that (1) 59% of the fourth graders, 69% of eighth graders, and 75% of twelfth graders reached the basic level or beyond; (2) 25%, 28%, and 37% of grade 4, 8, and 12 students met or exceeded the proficient level, respectively; (3) from 2% to 4% of students at any of the grade levels achieved the "advanced" performance level; (4) fourth graders within the basic level generally understood simple narratives; (5) eighth graders reading within the basic level demonstrated literal understanding of passages; (6) twelfth graders within the basic level were able to interpret aspects of the passages they read and make connections between their reading and their own knowledge; (7) students attending private schools had higher average reading proficiency than students at public schools; (8) considerable variation in performance existed within and across participating states; (9) females had higher average reading proficiency than males at all three grade levels; and (10) fourth graders appeared to be learning reading through varied instructional approaches. (Contains 67 tables and 9 figures of data; a detailed description of anchoring the achievement levels, an overview of procedures, state contextual background factors, and reading passages are attached.) (RS)