BANGOR — Many school districts have a lot of work to do before they will be ready to implement a new education system that, by law must be in place by 2018, according to the results of a Maine Department of Education survey that was released Wednesday.

Participation in the survey was voluntary, and only 73 of the 242 school districts answered the Department of Education’s questions, but Education Commissioner Jim Rier said the results gave his department a general sense of where districts are in the implementation of the proficiency-based diploma law.

“It drives home the point, for me anyway, about how much work we have to do,” Rier said Thursday.

According to the law, high schools will graduate students not after they’ve earned enough credits, but because they’ve demonstrated they’ve met the state’s knowledge and learning standards. The knowledge standards hit on eight subject areas, including math, English, science and social studies, but other standards tackle skills such as communication and critical thinking.

In May, the Department of Education announced that districts would be able to apply for one- or two-year extensions on the implementation of the new education system, called proficiency based education.

Seventy-five percent of the school districts that responded to the survey said they would apply for an extension.

On the whole, most districts indicated that they were ready to demonstrate that their students are proficient in the more traditional content areas — English, math, social studies and science.

But only 18 of the 73 districts that participated said they would be ready to show their students are proficient in the other content areas — physical education, health, visual and performing arts, world languages and career and education development — by 2018.

The Bangor School Department is one of the districts that will apply for an extension, according to Superintendent Betsy Webb.

She said some departments will be ready to implement the new system, but others will need more time, particularly to create the new assessments that teachers will use to determine whether their students have met the state’s standards.

Ninety percent of the districts that responded to the survey said they did not have a plan in place for how they would communicate the new changes in their education system to the general public.

At a superintendents conference held by the Department of Education this week, Rier said members of his department spent significant amounts of time relating how districts should be communicating with the public about what a proficiency-based education means.

The department and school districts need to be able to “answer some questions that the public has about why are we doing this anyway,” Rier said.

He acknowledged that proficiency-based education is a complicated topic but stressed that it is crucial that parents, students and educators understand the changes underway in Maine’s education system.

“This transition is extremely important,” he said. “It isn’t going to be accomplished in a year or two.”