I have an assignment over surveys and I am having trouble with a question. Any help would be appreciated.

Question;
How can one work to ensure the participants of a survey will have their responses kept private and the information gained is unbiased?

First, don't identify the participants by name, address, phone number, etc. Using an objective check list or rating scale, rather than the respondents' actual words will also help ensure their privacy and the information gained is unbiased. Probably the most objective form of a survey is a rating scale, rather than open-ended answers.