How can faculty researchers avoid undue influence of student subjects?

Avoid using their own students in their research in the first place

Explanation:

Due to high amount of interaction that they might possess, the students might form some sort of personal relationships with members of the researchers team.

When this happen, there would be a motive for the students to behave exactly in a way that the researchers want and make the research become invalid.

i heard they are taking it off i hope this isn't true but otherwise if it doesn't get taken off it will probably be in early december or early january of 2018-2019