In the United States, a "two-tiered" school system--elementary and secondary education--is often spoken of, yet throughout this century the trend has been toward a "three tiered" system--elementary, junior high/intermediate/middle school, and high school. This paper reviews literature and research regarding these trends, the advantages and disadvantages of both systems, and the effects of grade organization patterns on students. Particular emphasis is given to the middle/junior high school system. The paper concludes with suggestions for changing grade organization patterns. Appendixes include references, a chart showing secondary grade organization patterns, and an outline of advantages and disadvantages in the systems. (CB)