If you ask a question to people in a group who are already clearly for a certain topic then it is biased. For survey to not be biased, the people need to be chosen at random. Ask students what their favorite class is, or ask flight attendants where their favorite destination to travel to is. Dont use a group who has any relation to the survey at hand. Asking band students about funding for band is biased, as well as asking people who are at a SOCCER GAME what their favorite sport is.
