Within a few years, school districts in most states will have to have enough computers to allow students to take multiple tests online throughout the school year.

With new online tests being designed to reflect the Common Core standards adopted by 45 states and the District of Columbia, school districts in these states will have to replace pencil-and-paper testing with the new online exams as soon as the 2014-15 school year. But school leaders are unsure how the computers and software needed for such a move will be funded.

Last year, the federal Education Department doled out more than $300 million in Race to the Top funding to two groups of states to create next-generation assessments tied to the Common Core standards.

One of these groups, the Partnership for Assessment of Readiness for College and Careers (PARCC), includes 23 states and the District of Columbia. The other group, the SMARTER Balanced Assessment Consortium, includes 28 states. For now, Alabama, Colorado, Kentucky, North Dakota, Pennsylvania, and South Carolina belong to both consortia—and Alaska, Minnesota, Nebraska, Texas, and Virginia belong to neither.

A hallmark of these new next-generation state assessments is that students will take them online.

The tests will be a major change from how things traditionally have been done in many states. Rather than fill in bubbles on a multiple choice test or write answers in a blue book or on loose leaf paper, students will sit in front of computer screens several times a year answering questions online. Some questions will include the use of video.

The tests are designed to measure students’ 21st-century skills and ensure they are ready for college or a career. Testing students via computer offers many advantages, its proponents say: It allows states to design more rigorous assessments that include computer-based tasks, measuring students’ abilities in ways that a pencil-and-paper exam cannot. What’s more, the new tests are intended to be formative rather than summative in nature, meaning students will take them several times per year—and teachers will get immediate feedback they can use to inform their instruction.

But it’s unclear how much the transition to computerized testing will cost participating states or their school districts. School districts must have enough computers to allow a large number of students to take multiple tests throughout the school year.