TENNESSEE’S NATIONAL IMPACT
13 TENN. J.L. & POL’Y 523 (2019)
[531]
achievement growth as measured by large-scale
standardized test scores (i.e., the tests mandated by the
No Child Left Behind (NCLB) Act of 2001). The models
attempt to statistically control for outside variables,
including students’ prior test performance, and student-
level background variables (e.g., whether students are
eligible for free-and-reduced lunches).
22
The most widely used VAM is the EVAAS,
developed and used in Tennessee.
23
EVAAS
comes in
different versions for different states (e.g., the EVAAS in
Ohio, North Carolina, and South Carolina, the PVAAS in
Pennsylvania, the TVAAS in Tennessee, and the
TxVAAS in Texas) and different ones based on large and
small school districts (e.g., located within Arkansas,
Georgia, Indiana, Texas, and Virginia). For each
consumer, EVAAS modelers choose one of two
sophisticated statistical models.
24
Using these models, student growth scores are
aggregated at the teacher or classroom level to yield
teacher-level value-added estimates. Depending on where
22
See e.g., Sean Corcoran & Dan Goldhaber, Value Added and
Its Uses: Where You Stand Depends on Where You Sit, 8 EDUC.
FIN. & POL’Y 418, 421 (2013). Other variables include things
such as, English language learners (ELLs), gifted, receiving
special education services, and classroom and school-level
variables (e.g., class sizes, school resources, school leadership).
23
The EVAAS is advertised as “the most comprehensive
reporting package of value-added metrics available in the
educational market” in that the EVAAS offers states, districts,
and schools “precise, reliable and unbiased results that go far
beyond what other simplistic [value-added] models found in the
market today can provide.” SAS® EVAAS ® FOR K-12,
https://www.sas.com/en_us/software/evaas.html [https://perma.cc/
76AY-G47W].
24
For a comprehensive statistical summation of the various
models and options available, see WHITE PAPER: SAS®
EVAAS® FOR K12 STATISTICAL MODELS, https://www.sas.
com/content/dam/SAS/en_us/doc/whitepaper1/sas-evaas-k12-
statistical-models-107411.pdf [https://perma.cc/F5EW-WCB6].