Tennessee will move ahead with its plan to give schools a single letter grade after lawmakers shot down an effort on Wednesday to roll back the requirement.

With a 4-4 split and one pass, a proposal to replace letter grades with terms like “priority school” effectively died in the Senate Education Committee after a successful run through all House committees.

That means that debate will rage on over whether school quality can be summed up by a single letter grade. It also means that Tennessee will start a grading system in 2018 just as the idea is falling out of favor in many of the 18 states that have instituted them in recent years.

Last year, a bill requiring all schools to get an A-F grade sailed through the legislature. Supporters said parents needed an easy tool to understand how their child’s school is performing, even as critics — including many educators — argued that one letter grade would oversimplify school performance.

The bill would have given schools an overall rating ranging from “exemplary” to “priority.” It also would have given schools multiple letter grades highlighting how much students’ test scores improved, how high the scores were, and other measures “deemed appropriate” by the State Department of Education.

The bill was drafted by the state’s superintendent organization, whose members asked for a revised grading system that would illuminate where schools are struggling and to highlight successes. They compared the current grading system to giving students a single grade on their report cards, rather than separate grades for each subject.

“I just don’t think it gives a fair picture,” said Sen. Jim Tracy of Shelbyville, who sponsored the bill to change the current policy.

But committee chairwoman Dolores Gresham spoke passionately about the need for simplicity, saying that revising the system would be “a mistake.”

“Parents are not looking for nuance; they are looking for clarity. The bill in front of us will take us backwards by replacing A-F with a series of words full of nuance and words,” said the Somerville Republican. “The average parent doesn’t understand ‘priority school’ but they understand an F when they see it.”