Interviews for a new Norton superintendent of schools should begin in December or January, School Committee member Margaret Werner said. Specific dates have not been scheduled. The search committee’s roster was being finalized last week. The school system received about 20 applications as of Thanksgiving week, according to School Committee chairman Andrew Mackie, with the application period ending Nov. 30. Interim Superintendent Chris Martes, formerly superintendent in Foxborough, has been “very well received” in Norton, but cannot accept the permanent job because he is retired, Mackie said.