This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance levels--basic and above, proficient and above, and advanced; (2) Background information about limitations of the state's test data and characteristics of the state's testing system, including major changes in its testing system; (3) Figures and tables with the percentages of students scoring at the proficient level and above for all years with comparable data since 1999 and for all grades tested under the No Child Left Behind Act; and (4) Figures and tables with percentages of students performing at three achievement levels--basic, proficient, and advanced--for all years with comparable data and for grades 4, 8, and 10 (or adjacent grades, in the case of states that lack comparable trend data for these default grades). Ohio has made a number of changes to its testing program in recent years. As a result, the number of years with comparable test data varies for different grade levels and subjects. All trends extend through 2008, but the starting years are 2005 for elementary and middle school reading and middle school math, 2006 for elementary math, and 2004 for high school reading and math. Overall, Ohio students made gains at the basic and proficient achievement levels; results were somewhat more mixed at the advanced level. Specific results include: (1) The percentage of students performing at or above the basic level in reading increased slightly at the elementary and middle school grades analyzed and grew at a moderate-to-large rate at the high school level; in math, there was a moderate-to-large decline in the percentage basic at the elementary grade analyzed but moderate-to-large gains at the middle and high school levels; (2) In reading, the percentage of students scoring at the proficient level and above increased at a moderate-to-large rate at the elementary and high school grades analyzed and at a slight rate at the middle school grade; in math, the percentage proficient decreased at a moderate-to-large rate at the elementary grade analyzed but rose at a moderate-to-large rate at the middle and high school grades; and (3) There were slight declines in the percentage of students reaching the advanced level in reading at the elementary and high school grades analyzed but a moderate-to-large gain at the middle school grade; in math, the percentage advanced decreased at a moderate-to-large rate at the elementary grade analyzed but went up at a moderate-to-large rate at the middle and high school grades. (Contains 4 figures and 4 tables.) [For "State Test Score Trends through 2007-08, Part I: Is the Emphasis on 'Proficiency' Shortchanging Higher- and Lower-Achieving Students?," see ED506121. For "State Test Score Trends through 2007-08. Part II: Is There a Plateau Effect in Test Scores?," see ED506122.]