Akey concept embodied in the accountability provisions of the Elementary and Secondary Education Act (ESEA), as amended by the No Child Left Behind Act of 2001 (NCLB, P.L. 107-110 ) is that of adequate yearly progress (AYP) toward proficiency on state assessments. In order to maintain eligibility for grants under ESEA Title I, Part A—Grants to Local Educational Agencies (LEAs) for the Education of Disadvantaged Pupils, the largest federal K-12 education program—states must establish and implement standards of AYP that are applicable to all public schools and LEAs in the state, as well as the state overall. These AYP standards are to be based primarily, although not solely, on the scores of all pupils as a group, as well as pupils in designated demographic subgroups, on state developed or selected assessments that are linked to state standards of curriculum content and pupil performance. Schools or LEAs that fail to meet AYP standards for two or more consecutive years face a variety of consequences and, ultimately, corrective actions. The authorization for ESEA programs expired at the end of FY2008, and the 111 th Congress is expected to consider whether to amend and extend the ESEA. This report will be updated regularly to reflect major legislative developments and available information. Substantial interest has been expressed in the use of growth models to meet the AYP requirements of the NCLB. Such AYP models are not consistent with certain statutory provisions of the NCLB, as they were originally interpreted by the U.S. Department of Education (ED). In November 2005, the Secretary of Education announced a growth model pilot program under which up to ten states would be allowed to use growth models to make AYP determinations for the 2005-2006 school year. In December 2007, the Secretary lifted the cap on the number of states that could participate in the growth model pilot, and regulations published in October 2008 incorporate this expanded policy. Thus far, the applications of 15 states—Alaska, Arkansas, Arizona, Colorado, Delaware, Florida, Iowa, Michigan, Minnesota, Missouri, North Carolina, Ohio, Pennsylvania, Tennessee, and Texas—have been approved to participate in the pilot program. This report discusses growth and other models for AYP determinations, and analyzes issues related to the use of growth models to meet the AYP requirements of the NCLB. While AYP definitions or standards may vary in a multitude of respects, their basic structure generally falls into one of three general categories. The No Child Left Behind Act statute, as implemented by ED currently, places primary emphasis on one of these models, while incorporating a second model as an explicitly authorized alternative. In recent years, critics of current policy have increasingly focused their attention on a third model of AYP, which is the primary topic of this report. The three basic structural forms for AYP of schools or LEAs are the group status , successive group improvement , and individual/cohort growth models. In the context of these terms, "group" (or "subgroup," in the case of detailed demographic categories) refers to a collection of pupils that is identified by their grade level and usually other demographic characteristics (e.g., race, ethnicity, or economic disadvantage) as of a point in time, such as all Hispanic 3 rd grade pupils enrolled in a school or LEA in a particular year. The actual pupils in a "group" may change substantially, or even completely, from one year to the next. In contrast, a "cohort" refers to a collection of pupils in which the same pupils are followed from year-to-year, such as the Hispanic pupils who entered 3 rd grade in a school, LEA or state in fall 2002, and have been followed as a cohort since that time. The key characteristic of the group status model is a fixed "annual measurable objective" (AMO), or required threshold level of achievement, that is the same for all pupil groups, schools, and LEAs statewide in a given subject and grade level. Under this model, performance at a point in time is compared to a benchmark at that time, with no direct consideration of changes over a previous period. The key characteristic of the successive group improvement model is a focus on the rate of change in achievement in a subject area from one year to the next among groups of pupils in a grade level at a school or LEA (e.g., the percentage of this year's 5 th grade pupils in a school who are at a proficient or higher level in mathematics compared to the percentage of last year's 5 th grade pupils who were at a proficient or higher level of achievement). Finally, the key characteristic of the individual/cohort growth model is a focus on the rate of change over time in the level of achievement among cohorts of the same pupils. Such models may compare current performance of specific pupils or cohorts to past performance, or may project future performance of pupils/cohorts based on past changes in their performance level. Growth models are longitudinal , based upon the tracking of the same pupils as they progress through their K-12 education careers. While the progress of pupils is tracked individually, results are typically aggregated when used for accountability purposes. Aggregation may be by demographic group, by school or LEA, or other relevant characteristics. In general, growth models would give credit for meeting steps along the way to proficiency in ways that a status model typically does not. To help illustrate the basic differences among these three AYP models, simplified examples of basic aspects of each are described below. The reader should keep in mind many other variations of these model types are possible. A group status model, such as the current primary model of AYP under the NCLB (described further below), establishes a series of threshold levels or AMOs, which are percentages of pupils scoring at a proficient or higher level of achievement on state standards-based assessments of reading and mathematics. These AMOs have a starting point and a series of increases toward (in the case of the NCLB) an ultimate goal of 100% of pupils at a proficient or higher level of achievement, covering a multi-year period (for the NCLB, the period of 2001-2002 through 2013-2014). These AMOs are specific to each grade level and subject (reading or mathematics) at which state assessments are administered. A key feature of the AMOs in this model is that they are the same for all pupil groups—the "all pupil" group as well as each of the demographic subgroups specified under the NCLB (pupils with disabilities, pupils from low-income families, pupils with limited English proficiency, etc.). This model focuses solely on current year performance of the pupils currently enrolled in each school/LEA for every grade level at which assessments are administered. Comparisons to previous year performance play no role in AYP determinations. An example of a simplified successive group improvement model is the secondary ("safe harbor") model authorized under the NCLB. Under this model, as embodied in the NCLB, the basic structure of the AYP system is the same as described above, but the primary focus shifts to the change from the previous year for each group assessed. If any specified demographic group fails to meet the primary group status AYP criterion described above, the school or LEA is still deemed to meet AYP standards if the percentage of pupils scoring below the proficient level declines by 10% in comparison to the previous year for pupils in that grade level and demographic group. Thus, the primary focus shifts to the change in achievement from the previous year, comparing (for example) this year's pupils from low-income families in the particular school/LEA/grade level to last year's pupils from low-income families enrolled in that school/LEA/grade level (i.e., the pupils are in the same demographic category, but are not necessarily the same pupils). An individual/cohort growth model begins by tracking the performance of individual pupils over multiple (at least two) years. The performance of pupils in the same grade level who share relevant demographic characteristics within a school, LEA, or the state overall may be combined into a cohort. The change in scores for this cohort is compared to a standard of expected growth . The expected growth may be either "data-driven" (e.g., the statewide average rate of achievement growth for all pupils, or the predicted rate of growth statewide for pupils with similar demographic characteristics), or "policy-driven" (a multi-year growth path sufficient to meet an ultimate goal, such as the NCLB requirement for all pupils to reach a proficient or higher level of achievement by 2013-2014). A school or LEA is deemed to meet AYP requirements if the achievement growth of each relevant cohort of pupils meets the expected level of growth. The path of expected growth, as well as the starting points for the growth path, will likely differ for each relevant demographic group of pupils. Some growth models, often called value-added models , also incorporate a variety of statistical controls, adjustments to account for pupil demographic characteristics or past achievement, to sharpen the focus on estimating the impact of specific teachers, schools, or LEAs on pupil achievement and to measure pupil growth against predicted growth for pupils with similar characteristics, but these are not essential elements of all growth models. Proponents argue that such models, with their controls for background characteristics and past learning, maximize the focus on factors that are under the control of teachers and other school staff. The Tennessee Value-Added Assessment System (TVAAS) is one specific form of growth model that uses pupil background characteristics, previous performance, and other data as statistical controls in order to focus on estimating the specific effects of particular schools, districts, teachers or programs on pupil achievement. The primary model of AYP under the NCLB currently is a group status model.