State school officials confirmed Tuesday that percentages of students passing new, more rigorous English and math tests could drop by nearly half at some grade levels, cutting success rates to as low as 35 percent statewide.

Declines of that magnitude would mean that hundreds of thousands of students statewide and tens of thousands on Long Island would be added to the lists of those notified by local school districts that they have failed to attain academic "proficiency" and qualify for remedial tutoring.

Last year's proficiency rates for grades 3-8 ranged from 50 percent to 69 percent statewide and from 62 percent to 79 percent on the Island, depending on subject and grade level.

State testing for those grades is scheduled from April 16 through 26. Tests are scored on a range of 1 to 4, with 4 signifying excellence, 3 proficiency and 1 and 2 below proficiency.

For the first time, test questions will be based on national Common Core standards, which emphasize sophisticated English and math skills.

Top administrators in the state Education Department, who held a two-hour briefing for reporters Tuesday in Manhattan, reiterated past statements that the more difficult tests are largely meant to ensure that students can enter college without being placed in remedial courses -- a problem now.

advertisement | advertise on newsday

Most of Tuesday's briefing was on background, meaning those administrators could not be quoted by name. The session marked the first time that state officials have acknowledged to the news media just how steep the decline in test scores might be, though officials have made similar statements in closed meetings with local school superintendents.

At the end of the briefing, state Education Commissioner John B. King Jr. gave a short on-the-record interview.

"Certainly, the tests will be more challenging this year, because they're based on higher standards," King said. "We expect the numbers of students earning 3s and 4s initially will be less, but we expect that to improve over time."

The commissioner said exact passing rates won't be known until the department collects test results and arranges for setting of cutoff scores.

State testing experts have taken pains in recent weeks to emphasize that lower scores will be due to higher academic standards, not to greater failure on students' part.

Many local school administrators and teachers have objected that the state is rushing the new tests, and that many students who score poorly will feel stigmatized.

"My immediate concern is: Will our parents understand what's happening?" said Henry Grishman, superintendent of Jericho schools and a past president of the New York State Council of School Superintendents.