While online surveys have distinct advantages, their use in the general population presents several difficulties.
On the one hand, they share the advantages of self-administered questionnaire surveys:
- collection costs are lower essentially because no interviewers are needed,
- respondents can fill the questionnaires whenever it is most convenient for them,
- the absence of interviewers also allows for more personal questions (health, sexuality, etc.).
Online surveys also have their own particular advantages:
- they enable new question formats that integrate video, sound and interactive applications,
- moreover, the collection period can be reduced since there are no (or almost no) limits on the number of people who can be interviewed at the same time. In addition, answers are saved as they are being collected.
However, using the Internet to survey the general population also raises issues about the representativeness of the sample and the extrapolation of results:
- online surveys are conducted on the basis of volunteer samples, that is, nonprobability surveys,
- people without access to the Internet are effectively excluded. Yet in France in 2012, one out of every five people did not have Internet access at home (Gombault, 2013).
One way of overcoming these biases is to build an online panel from a random sample of the population. This means recruiting people offline, including people who do not have Internet access, and equipping them with a connection if needed. For the ELIPSS panel this is achieved by using a random sample of addresses drawn by the national institute of statistics and by providing touchscreen tablets with a 3G/4G connection to all the panel members.