School Size, School Poverty and School-Level Mobility: Interactive Threats to School Outcomes

ABSTRACT SCHOOL SIZE, SCHOOL POVERTY AND SCHOOL-LEVEL MOBILITY: INTERACTIVE THREATS TO SCHOOL OUTCOMES by Sharon M. Thompson School-level mobility is the flow of students moving in and out of schools and has been defined as the rate of student entries and withdrawals per 100 students enrolled in a school during the year (Pike & Weisbender, 1988). Stakeholders report that school mobility disrupts the delivery, pace and effectiveness of classroom instruction, causes problems associated with classroom adjustment, and renders long-term negative effects on schools’ Adequate Yearly Progress rankings (Bruno & Isken, 1996; GAO, 2007; Kerbow, 1996; Lash & Kirkpatrick, 1990; Rhodes, 2005; Sanderson, 2003). Despite these findings very few studies have been conducted to determine the effects of mobility (particularly at the school level) and how it combines with other school-level factors such as school size and school poverty to create threats to positive school outcomes. Of the few relevant studies (e.g., Bourque, 2009; Rhodes, 2007), little attention has been given to understanding mobility’s relationships to achievement in the context of size of student enrollment, degree of poverty and longitudinal examination of achievement across multiple years. To address these gaps in the research literature, this study investigated the effects of school-level mobility on middle school reading achievement after controlling for the effects of school enrollment and poverty. Findings from regression analyses indicated significant relationships between school-level mobility and reading achievement over and beyond the relationships between school size or school-level poverty with achievement. A repeated measures procedure was used to analyze long-term effects on eighth grade reading achievement for Title I middle schools that focused on three, key variables: degree of school mobility (e.g., high versus low rate), size of student enrollment (e.g. big versus small school), test administration year(s) (e.g., 2006, 2007 and 2008) and interactions between these variables. There were significant main effects for school size, school-level mobility as well as for the year of test administration. Reading test scores rose significantly from one year to the next, big schools out-performed small schools , and highly mobile schools performed significantly lower than low mobile schools in reading achievement over a three-year period. No significant interaction effects were found. Results are discussed in terms of research and policy implications