AUSTIN - Hundreds of thousands of Texas high school students continued to struggle on state English exams this year, potentially delaying their graduations, though their scores on less rigorous math and science tests improved.

Officials with the Texas Education Agency, which released the test results Wednesday, applauded the gains in some areas but acknowledged the comparatively poor performance in reading and writing.

"We must work together to assure our students are in a position to express themselves beyond 140 characters after they leave high school," state education Commissioner Michael Williams said in a statement, referring to the space limit on the social media site Twitter.

Several suburban Houston districts - including those in Clear Creek, Conroe, Fort Bend and Klein - surpassed the state average in every subject.

Scores in the Houston Independent School District, however, fell short in every area, with the biggest gaps in English. On the ninth-grade English exams, 61 percent of HISD students passed, versus 72 percent statewide. The sophomore English results had a 9-point gap.

"We've got to change the mind-set and the culture in our high schools to make sure our best English teachers are teaching ninth- and 10th-grade English," HISD Superintendent Terry Grier said. "I was a high school principal and, at least in the schools I worked, it's more prestigious to be an English 4 honors teacher."

Teachers have expressed concern about teaching in the tested grade levels, however, because of the high stakes for students and for them. In HISD, teachers' job evaluations are based in part on their students' test scores, and dozens of other districts this year will pilot a new test-based evaluation system developed by the state.

Grier said district officials are considering offering "boot camps" the summer before ninth and sixth grades to help strengthen students' language and math skills. The program, he said, would include classes with proven teachers and small group or online tutoring sessions.

On the algebra test, HISD's passing rate was 80 percent, six points lower than the state average.

Some area districts, including Alief, Katy, Spring and Spring Branch, declined to release their scores or did not respond to an email request.

Texas public high school students must pass end-of-course exams in five subjects to graduate: English I, English II, Algebra I, biology and U.S. history. State lawmakers originally required students to pass 15 exams, known as the State of Texas Assessments of Academic Readiness, but they scaled back last year after outcry from parents and educators.

Science, math results

Students took the STAAR exams, designed to be harder than the state's prior battery of standardized tests, for the first time in the 2011-12 school year.

Lawmakers are expected to wrangle over requirements again next session.

Statewide scores on the science and math exams reflected a sizable bump over previous years. In biology, 93 percent of students passed on the first try, up from 87 percent last year. The passing rate in algebra grew to 86 percent, a 4 percentage point increase.

The results on the English exams were not comparable to last year. The old STAAR exams included separate reading and writing tests, but lawmakers ordered them combined.

The higher scores on the math and science exams may also be attributed to easier standards. Students had to answer fewer questions correctly on those tests than on the English exams to pass. In algebra and biology, students had to answer 37 percent of questions correctly to meet the standard.

Holly Eaton of the Texas Classroom Teachers Association said she believes the lower English scores are attributable to recent changes, most notably shifting from separate four-hour reading and writing exams to one five-hour test.

"I think that has more to do with the length of the test - that they combined them and kids had trouble with it," Eaton said, adding the gains in science and math should not be ignored. "These scores are a real tribute to the remarkable ability of teachers and students to rise to the challenges the state sets for them even in these times of increasingly limited resources and support."

Results on the U.S. history exam, which most students take as juniors, exceeded expectations. The passing rate statewide was 92 percent.

Schools offer summer school for students who failed the exams, but getting them enrolled was difficult in some cases. In HISD, the state's largest district, high schools didn't receive students' scores until the last or second-to-last day of school.

In the subject with the poorest results, ninth-grade English, more than 177,000 students statewide failed the exam given this spring. That includes students who took the test for the first time and those who tried again after failing.

Tests also need work

State Rep. Jimmie Don Aycock, R-Killeen, who heads the education committee, has expressed concerns over whether the tests themselves need to be revamped. Monty Exter, lobbyist for the Association of Texas Professional Educators, agreed that the test needs work.

The idea of end-of-course exams had drawn support from some educators when lawmakers debated changes to the testing program. The state's prior high school exams covered general subject matter, so in some cases students were tested on material taught in earlier grade levels. The STAAR exams were supposed to cut down on the time teachers spent reviewing old concepts in class, but the tests also were designed to be harder - with more complex questions and a time limit.

Because STAAR results have not improved as quickly as expected in some areas, Commissioner Williams has left easier passing standards in place. He will decide whether to raise them after additional results come in this year, according to his staff.