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; (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); (5) Figures and tables with mean scale scores, standard deviations, and effect sizes for all years with comparable data and for the three grades analyzed in this study; and (6) Figures and tables with mean scale scores, standard deviations, and effect sizes for all years with comparable data and for the three grades analyzed in this study. Missouri made changes to its testing program in 2005. As a result, only three years of comparable test data (2006-2008) are available, the minimum number of years needed to identify a trend. Results at the basic, proficient, and advanced levels were mixed, but gains were made at most grade levels analyzed. Specific results include: (1) Between 2006 and 2008, the percentage of students scoring at the basic level and above in reading increased at a moderate-to-large rate at the elementary and middle school grades analyzed, but decreased at a moderate-to-large rate at the high school level; in math, the percentage of students at the basic level and above rose slightly at the elementary grade and showed a moderate-to-large gain at the middle and high school levels; (2) In reading, the percentage of students performing at the proficient level and above increased slightly at the elementary grade analyzed, rose at a moderate-to-large rate at the middle school grade analyzed, and decreased at a moderate-to-large rate at the high school level; in math, the percentage proficient went up slightly at the elementary level and at a moderate-to-large rate at the middle and high school grades; and (3) The percentage of students reaching the advanced level in reading decreased at a moderate-to-large rate at the elementary grade analyzed, fell slightly at the middle school level, and rose slightly at the high school level; in math, the percentage of advanced students declined slightly at the elementary level but increased slightly at the middle and high school grades. (Contains 6 figures and 6 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.]