My son will has a summer internship in the state of Mass. And will earn somewhere between $7850 and $8700. He will be residing in a dorm as he is working for a lab associated with one of the colleges near Boston. His only other source of income for the year will be about $100 in interest income. He is 20 years old and for federal tax purposes, is still a dependent of his parents who pay for his college education. Regarding MA state income taxes, he is considered a Non-Resident. Is he also considered a Part-Year Resident since he will reside near there during the 2-months he is earning this income?? Also, I assume he still qualifies for the $4400 exemption for a single taxpayer even though he is a dependent of his parents; is this correct?

Assuming your son's residence with his parents is OUTSIDE of Massachusetts, by law, he is considered to be a non-resident of the state of Massachusetts due to his status as a college student.

Yes, he will qualify for the reduced standard deduction.