YORK — The York High School Class of 2021 has an unusual distinction.

As freshman, they were expected to be the first graduating class with a proficiency-based diploma as required by Maine law at the time. That included the implementation of a 1-4 grading system that many parents found confusing and problematic.

By the end of their freshman year, the law requiring a proficiency-based diploma was repealed. YHS almost immediately instituted the old 0-100 grading system familiar to everyone. But the Class of 2021 used that 1-4 system in the 2017-2018 school year. The challenge for administrators, said Principal Karl Francis, was how to deal with those freshmen grades.

“We were faced with the fact of what do we do? The reporting piece was problematic to parents and staff. Parents didn’t understand it and teachers were learning the system as they were implementing it. It was extremely difficult for teachers teaching 0-100 for many years to just switch,” he said.

At the same time that teachers were acquainting themselves with the new reporting system during that freshman year of 2017-18, many were also implementing a standards-based system of teaching. In this system, teachers set individual standards that students are expected to understand, as well as benchmarks to reach the standard.

That work has paid off in big dividends, said Francis, even though he admits it was a hard slog for some teachers to switch to not only the new grading system but the new teaching system as well. Today, all classes 9-12 are being taught using a standards based approach, he said.

“We built a strong framework of academics as a result. There’s so much value and clarity in the alignment to the standards. We all saw the value in that,” he said. “We have systems in place to monitor student progress, and we have remediation and support systems in place for students not progressing. And it’s clearer to students and to teachers about what we want our students to learn.”

When the class of 2021 returned to school as sophomores last fall, they were graded on a 0-100 scale like all the other students. But that still left those freshmen grades. “We had to figure out what to do for these kids, to reflect the learning that they received their freshman year. What were we going to do with those 17-18 academic records?”

The idea behind the 1-4 system is to show how students are progressing in a fluid way throughout the year. In a 0-100 system, students receive a grade per quarter that indicates their knowledge for that particular quarter. They are very different systems, said Francis.

A committee formed last fall that included students because “they had a stake on how it would be handled and be a fair representation of their work.” The committee also sought feedback from parents, college admissions officers and from other students in that class.

It was decided to convert the records, a process that was “hard because we wanted to do it right. It was hard because we had two different systems. What was the fairest way that would do right by the Class of 2021?”

To make the conversion, Francis took on the task of looking at freshman courses for the three years prior to the 17-18 year, and broke down how many students received an A+, A, A- and so on based on that 0-100 scale. He then came up with an average percentage of numbers of students receiving each of those grades. These were used as the baseline in the conversion.

Assistant Principal Ellen Connell then developed an algebraic equation that further determined where students would fall between, say, an A, or 97, and an A-, or 93. The student could then convert a 93, 94, 95, 96 or 97 based on their specific 1-4 year-end average.

The system was then vetted by the University of New Hampshire mathematics department, which confirmed “that we had developed a system that would accomplish our goal and that it had mathematical and statistical validity and reliability.”

Last week, YHS administrators were finishing the conversations, with the goal of sending the grades out this week. Francis said he knows that some parents may continue to have questions, and he encourages them to call him at the high school.