Because this was done during the interview, the participants just spoke out their rating rather than marked it done on the paper: they sometimes say "I think it is between 2 and 3" or "I give it 4 or 5". I want the rating to fully represent their thinking, and that's why I put 2.5 and 4.5. I don't know whether it is legitimate though.
So the question is:
In the cases when participants gave rating of 2.5 or 4.5 on a 1-5 scale, shall I change it to an integer when performing non-parametric test? If so, how shall I do the adjustment? 2.5->3?? or 2.5->2??