When determining how to administer the survey, you should consider the number of people in your organization available to help administer it, the length of the survey, the number of people you are targeting to complete the survey, and accessibility to the survey respondents.
If your goal is to survey a large number of people or ask a higher volume of questions, it may be most efficient to administer the survey online. Using an online survey, however, may limit the respondents to only those with online access. Phone and in-person surveys will require staff or volunteers to administer the survey.
In all cases, data security must be considered to protect private information gathered over the internet, telephone or in-person.