The judgment of the Superior Court upholding the arbitration award is vacated.1 The matter is recommitted to the arbitrator for further proceedings.
So ordered.
Separate opinions of Justice Cordy, with whom Chief Justice Marshall and Justice Sosman join; Justice Ireland, with whom Justice Cordy joins; and Justice Cowin, with whom Justice Gre-aney and Justice Spina join.
We acknowledge an amicus brief filed by the Massachusetts Association of School Superintendents and one on behalf of Massachusetts Teachers Association/NEA; Massachusetts Federation of Teachers, AFT, AFL-CIO; Council 93, American Federation of State, County and Municipal Employees, AFL-CIO; and Massachusetts AFL-CIO.