The New York State achievement tests were designed to measure student "proficiency"—that is, whether students know the material they should for their grade level. The first chart below shows that the trends in District 7 elementary schools are somewhat stable when the tests are used specifically for this purpose. However, the trend lines begin to split and jump wildly when these test scores are used to compare one school against others citywide, as New York City's progress reports do. We offer a step by step explanation of this phenomenon below.
DISTRICT 7 SCALE SCORE TRENDS FOR GRADE FOUR READING AND MATH: 2000-2009
New York State public school students, grades three through eight, are required to take a set of achievement tests each spring designed to measure their mastery of that year's reading and math material. Students are assigned a score, known as a "scale score," which is similar to an SAT score in that it has no meaning by itself but takes on importance when placed in context or compared to the scores of other students. New York State officials have designed the scale so that a score of 650 marks the all-important threshold of "proficiency," meaning that the student has a solid understanding of that grade's material. Testing experts prefer to work with scale scores because they are finely tuned and tend to be reliable year to year. In this chart, we see that average scale scores for the grade four reading and math have been climbing in District 7 since 2000, a trend seen statewide.
DISTRICT 7 PROFICIENCY SCORE TRENDS FOR GRADE FOUR 2000-2009
The city compares individual schools by "proficiency scores"—a measure of the number of students performing at grade level. This is the mostly closely watched indicator of a school's success. The federal No Child Left Behind Act requires that all students be "proficient" in reading and math by 2014 and there is enormous pressure on educators to get these numbers as high as possible. Though the general trend has been upward in District 7, we see in these charts that the percent of students performing at grade level in any given year tends to go up and down at most schools—sometimes quite sharply. This is problematic if schools are being judged on their progress from the prior year. Testing experts recommend that high-stakes evaluations of schools, like the New York City Progress Reports, use at least three years of combined results to deal with natural volatility.
DISTRICT 7 NYC PERCENTILE RANKINGS FOR GRADE FOUR READING AND MATH: 2000-2009
Click chart to enlarge
The final chart illustrates how a school's rank compared to other schools citywide can change from year to year. This chart uses an average of the reading and math scale scores in fourth grade to examine how District 7's schools stood up against NYC's other elementary schools over the last decade. The New York City Department of Education uses various ranking systems to see which schools have made the most progress with their students on test scores from the prior year. The most important ranking system is the percentile score assigned to a school on the New York City Progress Report. In elementary and middle schools, this rank is created using a complicated set of calculations based mostly on state test scores. The DOE has worked to make these calculations more fair by looking at all grades in a school and by giving schools extra credit for working with more challenging kids, but they are still fundamentally based on test scores, which can be very unpredictable when ranked.
SOURCES: NYC Department of Education math and English Language Arts student proficiency data, 2000-2006; NY State Education Department math and English Language Arts student proficiency data 2006-2009. District 7 elementary schools only. K-8 schools, charter schools and new schools with less than two years of test data were excluded.