The Tennessee Value-Added Assessment System measures academic progress. Here's how it's measured:
* Did each group of students make a year's worth of growth in reading, math, science and social studies for grades four through eight?
* Did each subgroup of students make a year's worth of growth in reading, math, science and social studies for grades four through eight?
* Did each group of students make the state's average progress in end-of-course subjects, such as Algebra I or English II?
* Did each subgroup of students make the state's average progress in end-of-course subjects, such as Algebra I or English II?
* Is each individual student on a trajectory to reach proficient or advanced levels on a future TCAP end-of-grade Achievement or end-of-course assessments as well as college readiness indicators such as ACT, EXPLORE or PLAN?
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Test scores fell in Hamilton County in 2015, as measured by the Tennessee Comprehensive Assessment Program, or TCAP, and the school was given the lowest possible rating by the state on a composite measure of system performance.
Students posted gains in four subjects between 2014 and 2015, like math in grades 3 to 8 and Algebra II, but scores declined in five subjects in 2015 amid dips in reading, biology and English, according to the county's report card.
Even in areas where the school system posted gains, just half of all students scored as proficient or above when subjects are averaged together.
Chemistry was by far the worst subject, with less than a third of students ranked proficient or above. English I was Hamilton County's best subject, with just over two-thirds of students receiving a proficient or above rating.
Among traditional schools where students took the ACT, Signal Mountain Middle/High School ranked the highest, with a 23.9 composite score for the year. The Howard School ranked lowest, posting a 14.3 composite score. Though Howard posted the worst ACT score, it wasn't the only one to score lower than the minimum ACT score needed to get into the Volkswagen Academy, which is a 19 in reading and math and an 18 in English, according to an application packet from Chattanooga State.
Across the board, the county received a 1 overall — the lowest score possible out of 5, indicating that the county is showing less-than-expected academic progress — on the Tennessee Value-Added Assessment system, which uses various sources of data to measure school systems in comparison to one another.
That ranking put Hamilton County dead last among major metro areas. Knox, Davidson and Shelby counties all received scores of 5 overall, indicating that they are exceeding academic expectations.
Around the region, Bledsoe, Marion and Sequatchie counties also scored a 1, Meigs and Rhea counties scored a 3 overall, McMinn County scored a 4 and Bradley County scored a 5,
Tennessee also released information on Hamilton County's graduation rates, which rose slightly to 85.4 percent from 84.5 percent in 2013, after dipping to 82.6 percent in 2014. That's still lower than the statewide average of 87.8 percent.
Knox County graduation rates were much higher at 90 percent, while graduation rates in Davidson County were lower, at 81.6 percent in 2015, and in Shelby County the graduation rate was just 75 percent for the year.
Hamilton County's ACT scores climbed two decimal points to 18.9 in 2015, but still lag the state average of 19.4. But that state average isn't bolstered much by Shelby County, which has just a 16.9 average ACT composite, or by Davidson County, which at 18.7 is just under Hamilton County's average score. Knox County scored above the average, posting a 20.7 composite score.
Per-pupil expenditures in Hamilton County also rose from that same period, to $9,728,80 per student this year from $9,444.44 in 2013, though expenditures peaked in 2014 at $9,752.30.
Knox County, for comparison, spent $9,043 per student, while Shelby County and Davidson County spent much more: $11,221 per student in Shelby County, and $11,496 per student in Davidson County in 2015.
Though Knox County handily outperformed Hamilton County in several categories, some experts say that poverty can play a role in students' learning outcomes. Hamilton County has a much higher percentage of students — 60 percent — than the 40 percent who are economically disadvantaged Knox County.
Hamilton County's percentage of disadvantaged students is just 2.3 above the state average, balanced out by a lower percentage of students with disabilities, 12.7 percent, than the state average, which is 14 percent.
Hamilton County did have a slightly higher number of students who are classified as "English learners," at 5 percent, than the state average of 4.6 percent.
In terms of demographics, the state's report card revealed that 31.1 percent of Hamilton County students in 2015 were classified as black or African American, while 9.6 were classified as Hispanic or latino, compared to 24.1 percent and 8.5 percent, respectively, statewide. 56.5 percent of Hamilton County students are classified as white, a number that rises to 64.9 percent statewide.
The state released district-wide scores on Thursday, including individual scores for each school.
This story was updated on Oct. 23, 2015 to remove misinformation about UTC and Volkswagen standards.