One must also use language that will not offend persons providing the data. Some groups and individuals may express a preference. Good approach to have members of the group help design the study. Collecting Data cost - collecting data can be expensive. Choose a method that meets with your budget.
Subjects have a right to privacy and confidentiality.
They should be told who has access to the data. In general, research data do not have privileged status. There are some situations when the participants may want to be identified. Care must be taken to ensure the survey is the same in each case. Different versions of the survey will make data analysis much more difficult.