See:
https://www.irs.gov/individuals/international-taxpayers/fulbright-grants
which says, in part:
For tax purposes, a scholarship/fellowship may be defined as an amount given to an individual which has the following characteristics:
- It is paid to aid the individual's pursuit of study, training, or research;
- It does not constitute compensation for personal services - past, present, or future; and
- It is paid more for the benefit of the grantee than the grantor.
For tax purposes, compensation for personal services represents an amount paid to an individual in exchange for his performance of personal services - past, present, or future. Compensation for personal services usually takes the form of either wages or self-employment income.
