Statistical Growth Plots

Statistical Growth Plots (SGP) utilize longitudinal student data to produce percentile ranks of current test scores relative to students with similar prior achievement levels. This approach provides more accurate and holistic measures of student performance than unadjusted standardized test scores. Moreover, SGPs are more reliable and more valid than latent achievement trait models which may suffer from large estimation errors.

SGP analyses are typically conducted using the lower level functions studentGrowthPercentiles and studentGrowthProjections. These functions are designed to work with both WIDE and LONG formatted data sets. The SGPdata package, installed when you install the SGP package, includes exemplar WIDE and LONG formatted data sets (sgpData and sgpData_LONG, respectively) to assist you in setting up your analyses. The SGP package also includes wrapper functions (abcSGP and updateSGP) which “wrap” the above 6 steps into a single function call, simplifying source code associated with operational SGP analyses.

The sgp data sets contain anonymized student-instructor lookup tables (sgpData_INSTRUCTOR_NUMBER) which provide the instructor number for each teacher associated with a student’s test record. Each teacher can (and will) have more than one student associated with their test record. In addition, each teacher can be assigned to multiple content areas for a given year. The sgpData_INSTRUCTOR_NUMBER data set contains the instructors for each of these content areas and for each student for a given year.

The SGP data set sgpData_LONG contains the students and test records for each year of the study. It also contains the teachers and instructional settings for each of these years. This is the data that will be used for calculating SGPs.

A complete list of all test records for each student and for every teacher in a content area is included in the sgpData_LONG file. This is the source for all SGP calculations.

Located on 160 acres of cattle pasture and wheat fields southeast of Lamont, Oklahoma, the SGP site hosts instruments and infrastructure for atmospheric research. The facility includes the heavily instrumented Central Facility and numerous smaller, unstaffed observatories throughout the field. Technicians, support staff and observers monitor continuous data from the instrumentation.

In addition, the SGP site serves as a hub for guest instruments during field research campaigns and as a venue for the deployment of Earth System Models.

The sgp data sets contain an abundance of high-quality observations and simulations to meet the needs of researchers worldwide. These data are used for a variety of applications, from single observation process studies to multi-observation process studies and assimilation into Earth System Models. The sgp data sets are used in a wide range of disciplines, including meteorology, climate science, oceanography and environmental sciences. SGP scientists and collaborating institutions collaborate to make the data available in order to meet diverse user demands. The SGP data are available for scientific analysis, education and public outreach. The sgp data sets are provided free of charge to the international research community.