Ongoing strategic planning and continuous quality improvement requires quantifying the impact that expenditures, programs, interventions, and personnel have on student outcomes. However, attributing student growth to a specific teacher, program, or intervention is complex due to a variety of contributing factors that may explain the academic performance of students. The challenge is that most local school systems do not have the analytic sophistication and/or capabilities within their organization to choose and implement conceptually simple, yet scientific and defensible models.
Research on value-added growth models warns against implementing over-simplified models, such as defining growth as the difference between a pre-test and a post-test. Instead, research indicates that the most valid and reliable growth models define growth normatively and use data longitudinally by incorporating multiple historical data points on individual students. This approach ensures the influence of demographic and contextual variables are mitigated to an ignorable level and that the effects of programs and personnel can be separated from external influences.
School systems must extend their capacity and capabilities through external partnerships. Local Growth Models, or LGMs, offer a systemic approach to measure student, program, and principal and teacher performance. LGMs are value-added growth models built at the local school system level upon the existing assessment foundation and practices of the school district. By generating a unique comparison for each student based on his or her individual past performance, the variance between a student's actual achievement and his or her projected achievement can be examined. Such information then can be aggregated and linked to district resource allocations so that decisions can be made regarding schools, programs, and personnel. Local Growth Models provide a single reliable model to:
- monitor individual student growth and identify students for special programs or courses
- incorporate student achievement into principal and teacher evaluation
- document return on investment for programs and interventions
- support leadership and governance.