Don't give New York City's schools a standing ovation just yet.

Certainly, the city's overall improvement in state English Language Arts and math tests are significant because the gains closed the gap with statewide scores.

But don't applaud mediocrity. Only 30% of city students scored "proficient" -- either a 3 or 4 -- in reading, and 35% did so in math. There's a long way to go when a third of students meet state and national standards.

Set up an account, if you haven't already, and see your children's scores at the city's new portal, mystudent.nyc.

Even small gains are good signs when more difficult tests and tougher standards are still in their infancy. Score increases for black and Hispanic students are promising, though incremental. Still, NYC outperformed the other "Big 5" districts: Buffalo, Rochester, Syracuse and Yonkers.

What's more, NYC students deserve an A-plus for simply taking the exams amid a furor that led 20% statewide to opt out. Less than 2% refused in NYC.

City officials note that the changes they've made to high-need schools, known as Renewal Schools, in everything from lengthening the school day to improving school-community ties, won't start in earnest until September. Next year's results, therefore, will be even more telling.

But city officials also should watch what high-performing schools, including charters, are doing right.

In the Bronx, nearly every school where 70% or more of students reached proficiency were charters, with Success Academy and Icahn schools at the top. There's something to learn from a Success Academy fourth-grade class where 97% of students score a 3 or 4.

At the same time, the data also show charters struggle, too. Across NYC, the percentage of charter students maintaining a 3 or 4 in ELA stood just below the 30% mark, and some charters, just like some traditional public schools, saw proficiency rates at 10% or lower..

The city can't take a bow yet for its state test performance. But officials can build on it by learning from the best, and by focusing on those that need the most help.