AYER — The Ayer-Lunenburg-Shirley School District Regionalization Planning Board received a presentation on two assessment models the board will need to choose from to form a regional district.

“There is a challenge tonight,” consultant Mark Abrahams said. “You’re going to get overwhelmed by a lot of numbers, but the key is to get the big picture at the end.”

“Fundamentally, there are four things that go into the assessments,” Abrahams explained. “Transportation, capital, required district contribution and excess of net school spending.”

“The goal of the presentation is not to give numbers to the board or the public,” Chairman Milree Keeling said. “The goal is to see what the assessment models are and how we will come to create ours.”

There are two assessment models — statutory and alternative. In both models, there are several options on how the transportation and excess net spending assessments are calculated.

The options for transportation include: Net transportation costs, the number of bus runs in each town, the number of students using transportation in each town, the number of students using transportation for more than 1.5 miles, and an average of the previous four options.

The five assessment options for excess of net school spending include: Foundation enrollment, which represents all students that live in the communities regardless of which school they attend; head count enrollment, which represents students attending school in one of the three communities; residential enrollment, which is based on students who live in one of the three communities and attend school in one of the three communities; average enrollment, which is an average of the first three options; and direct assessment, which is the difference between total eligible net school spending and the local required district contribution.

“We need a model we believe is fair to present to our towns,” said Keeling. “We want it to be explainable and also for it to be able to be tracked back to each town.”

The model chosen must be voted annually at town meeting. The difference is that statutory requires a two-third vote while the alternative assessment requires 100 percent.

“What that means is for statutory, only two of the towns have to be in favor of the assessment,” Abrahams said. “With the alternative, all three towns have to pass it each year.”

The board is meeting Dec. 13 at the Lunenburg High School library from 8 a.m. to 12:30 p.m. to go over the different options.

“I would like us to at least tackle the transportation assessment and come to a conclusion on which option we want to use.”

Keeling said the savings the different School Departments would see by having only one central office would stay with the school.