The School Committee began a voluntary training program last month that is designed to help school officials improve student achievement through more cooperation. According to the Massachusetts Association of School Committees, a number of districts were invited to participate and the program helps streamline boards and administration. Committee chairman Paul Samargedlis said he decided to have the committee participate during the next 18 months as an exercise of self-evaluation. “I thought it would help us be a more efficient committee and better serve our constituents and students,’’ he said.