PHOENIX — Arizona students will still have to take — and pass — the AIMS test to graduate, at least for the foreseeable future.

Maricopa County Superior Court Judge Kenneth Fields refused to block the state from using the test as a condition of getting a diploma. He said its foes have not convinced him he should intervene now.

Fields' ruling does not end the case. The challengers still have the opportunity to prove at a full trial — possibly next year — their argument that the test is unfair and discriminatory.

But the chances the judge will side with them appear minimal at best: Fields said the more he hears about the issue, the less he believes that any judge has the right to overrule the Legislature on this issue.

The new ruling is not a total defeat for the challengers. Fields did agree to certify the case as a class-action lawsuit.

That allows Ellen Katz, attorney for the William E. Morris Institute for Justice, to legally represent the thousands of students who she argues are less likely to be able to pass the math, reading and writing portions of the test, formally known as Arizona's Instrument to Measure Standards. That includes economically disadvantaged students, racial- and ethnic-minority students and students classified as English-language learners because they are not proficient in the language.

The lawsuit cites statistics showing that these groups — comprising about one of every six of the state's 62,000 high school seniors — pass the math, reading and writing sections of AIMS at a lower rate than those not in the same categories. And it says the state should be providing more funding for these students for everything from smaller classes to tutoring.

State Superintendent of Public Instruction Tom Horne didn't dispute the figures. But he said there are additional state and federal funds for many of these students.

But Fields' ruling is based on Horne's other argument, that how much extra money to provide for these students is a "policy matter" solely within the purview of the Legislature.

The judge noted that Katz is arguing that the failure of lawmakers to adopt the recommendations of a funding study shows that the state is failing to meet its constitutional obligation to educate its children.

But Fields said that puts him in the position of deciding what level of funding — and what programs — are more appropriate than those now offered. And he would have to enforce that by forbidding implementation of the Legislature's requirement that students pass AIMS to graduate, something he said "exceeds the court's powers."