Sunderland Elementary, Readsboro Central, Bennington Elementary and Catamount Elementary schools were among the worst performing in the county.
Meanwhile, students at Dorset Elementary, Manchester Elementary/Middle, Mount Anthony Union Middle and Shaftsbury Elementary schools did especially well on the New England Common Assessment Program test, according to the Vermont Department of Education.
The NECAP replaces a previous examination and was administered to all Vermont public school students in grades three through eight last fall. Students tested in three areas: reading, mathematics and writing.
Statewide, 67 percent of Vermont students tested were proficient or higher in reading. In mathematics, 63 percent of students were proficient or higher. In writing, 53 percent of students tested were proficient or higher.
A majority of students at 10 of 16 schools in the county tested below the state average in reading. In mathematics, 12 of the schools had fewer students scoring proficiently than the state average.
Of the 14 schools with results on the writing segment, half had fewer students than the state average scoring proficiently.
Sunderland Elementary had just 44 percent of students testing proficiently in reading, and only 24 percent proficient in math.
Readsboro Elementary had 63 percent of its students proficient in reading but only 43 percent proficient in math. Just 20 percent of students were proficient in writing, the lowest percentage in the county for that category.
Principal David Switz said he was taking the news in stride.
"Overall, the numbers didn't look that great," he said. "We were surprised."
Switz said he would analyze the results in the coming weeks to determine a plan of attack.
Students in the Southwest Vermont Supervisory Union, overall, fared better than the state in writing, with 58 percent scoring proficiently or higher.
But the math and reading results were less than flattering.
About 62 percent of SVSU students scored proficiently in reading, 5 points below the state average. Only 53 percent of students scored proficiently on mathematics, 10 percentage points below the state average.
SVSU Superintendent Wesley L. Knapp said the math scores, in particular, were disappointing. He said officials will be making changes to classroom curriculum, textbooks and other materials to improve results.
"It's an area of weakness we're already working (to address)," he said of the math scores.
Two SVSU schools - Bennington Elementary and Catamount Elementary - each had fewer students testing proficiently than the state average in all categories.
Knapp said that the supervisory union's schools are "moving forward," noting that scores have been on the rise for five years. He said there were some "pockets of brilliance" among the testing schools this year.
Among the SVSU schools that fared particularly well were Monument Elementary School, Mount Anthony Union Middle and Shaftsbury Elementary. All three did well on reading and writing compared to the state average.
Outside the SVSU, Dorset Elementary and MEMS, both part of the Bennington-Rutland Supervisory Union, fared better than the state average across all testing categories.
The former had the highest scores in all categories for the county.
"I'm extremely pleased with the results," said Dorset Elementary Principal James Merryman, whose school had more than 80 percent of students testing proficiently. "We try to hold to best practices and it seems to have fared well so far."
MEMS Co-principal Jacqueline A. Parks was equally impressed with her students, saying the results are due, in part, to math and reading initiatives school officials implemented in the last 12 months.
"Those have been a focus for us over the past year," she said. "We were thrilled with the results, particularly in mathematics."
On the old exam taken the previous year, the school had a little more than half its students proficient in math. Now, about three-quarters of the students fit that category.
Because the state is only getting the results to school districts now, Knapp said officials will be hard pressed to make adjustments before the next round of testing.
But Education Commissioner Richard Cate said the idea is for school administrators to use the information to make modifications next academic year, not just before the test is given.
Cate said he was pleased with the statewide results overall but noted there were clear achievement gaps between boys and girls, and between students from low-income families and their peers. Girls and students not eligible for free and/or reduced lunch generally outperformed their counterparts.
The tests are required under the federal No Child Left Behind Act.
State leaders will use the results to determine which schools have achieved yearly progress standards and which will be included on a list of schools needing improvement under the federal law.
AYP determinations will be announced in early May. Mount Anthony Union High School is expected to make AYP because the determination will be based solely on its good graduation rate.
Sunderland Elementary School Principal Susan Hackett didn't return a phone message seeking comment.