Flanked by the city’s top education officials, Mayor Muriel E. Bowser (D) held a news conference Thursday to celebrate the District’s progress in performances on a national standardized test.

Black and Hispanic children citywide improved. Elementary schools in low-income neighborhoods showed promise. And middle schools made big gains.

But little was said at the news conference about the city’s neighborhood high schools — campuses that have received increased scrutiny after a city investigation found that one-third of 2017 graduates received their diplomas in violation of city law.

At some of those high schools, fewer than 5 percent of teenagers who took the test were declared ready for college or careers, according to results released this week.

The scores portray an education system where modest improvements at the lower grades haven’t caught up to the upper grades.

Frank W. Ballou Senior High School — which was at the center of the graduation imbroglio — reported a six-percentage-point decrease in students passing the English portion of the exam. In 2018, about 3 percent of students passed the English exam at the Southeast Washington school, and fewer than 1 percent passed the math section.

At Calvin Coolidge High School — another neighborhood school in the traditional public system — fewer than 5 percent of students taking the test passed English, which represented a 10-percentage-point drop from the previous year.

“We are seeing a lot of improvements in elementary schools, which are starting to translate to middle,” said Josh Boots, executive director of EmpowerK12, a nonprofit education data analytics firm. “Will we in three or four years start to see that in high school?”

City leaders announced Thursday the results of the computerized Partnership for Assessment of Readiness for College and Careers test — widely known by the acronym PARCC and administered in the spring. The test evaluates students on a five-point scale, with those who earn fours and fives meeting or exceeding expectations and considered “college and career ready.”

Students are tested each year in grades three through eight and once in high school, as required by federal law.

Students at Abram Simon Elementary and John Hayden Johnson Middle — two schools that feed into Ballou — made significant improvements on their tests.

But officials warned that significant progress is still needed, with only about one-third of students citywide meeting expectations on math and English exams.

Those averages are lower in the high school: About 30 percent of high schoolers passed the English exam in 2018, while 14 percent passed the math one.

At Ron Brown College Preparatory High, an all-boys campus in the traditional public school system that opened in 2016, 1 percent of students passed the math exam and about 14 percent passed English.

Shawn Stover, interim chief of secondary schools for D.C. Public Schools, noted that many high school students improved on the test even if they didn’t pass it. More than 10 high schools in the traditional public system had fewer students earning ones and twos on the math and English tests.

“The 2018 PARCC results help us get a better picture of our students’ readiness for college and career, and we look forward to digging deeper into the data to help us focus on the areas that need improvement,” Stover wrote in an email.

Standardized test scores are controversial measures of student achievement because students from wealthier families tend to perform better on the tests. In the District, neighborhood high schools that primarily serve students from low-income families — including Ballou, Anacostia, Roosevelt and Coolidge — recorded decreases in scores or remained stagnant.

Woodrow Wilson High School, the neighborhood institution with the most students from upper-income families, performed better than its peers, with 55 percent of students passing the English test and 33 percent passing math. Application high schools, including Benjamin Banneker and McKinley Technology, scored well above city averages and made vast improvements this year.

Kevin Welner, director of the National Education Policy Center at the University of Colorado at Boulder, said the public should be wary of reading too much into the test scores because they tend to heavily favor wealthier children.

Some charter schools that serve large populations of children from low-income families — including KIPP, Thurgood Marshall Academy, Friendship Tech Prep and Washington Leadership Academy — recorded big increases in scores.

“People want to read into these test scores lessons about what the schools are doing. But these scores, even the growth scores, depend a great deal on students’ opportunities to learn outside of school,” Welner said. “If we address the poverty and racism, then we will see these test scores increase.”

Many charter high schools also reported decreases in test scores. Richard Wright Public Charter School for Journalism and Media Arts saw a nine-percentage-point decrease on its English test, and a two-point increase on math. E.L. Haynes Public Charter School experienced a 14-point drop in math.

Hilary Darilek, chief executive at E.L. Haynes, said the test is just one metric of students’ progress.

“We believe that PARCC is an important assessment, and it is only one measure of our high school students’ performance each year,” Darilek wrote in an email. “Last year, we also saw increases in both PSAT and SAT scores, and our students earned 43 passing scores on Advanced Placement exams — a significant increase over the year before.”