How personalization and authentication affect Internet surveys
Internet surveys are an efficient way of collecting information. They have been shown to increase self-disclosure for sensitive questions, and also reduce “good” answers (more socially acceptable responses).
An interesting dilemma occurs when the participant comes across a question they might not want to answer, such as, “What is your salary?”
They can choose to passively not answer (no response, or the default choice), or they can actively not answer (selecting the option “I prefer not to answer”).
Authentication is when the participant needs to log in to take the survey, as opposed to going to a URL that encodes the participant’s information in the address. One of the studies shows that “I prefer not to answer” was chosen more often when authentication (log in) was used, versus when the URL encoded the information.
Personalization is when the email inviting the participant to do the survey had a salutation that identified the participant. The salutation would be something like “Dear Napoleon” instead of “Dear Student”. In the study, surveys where the invitation email had a personalized salutation did not generate a significant difference in non-responses to sensitive questions. However, it did ratio of active non-responses (“I prefer not to answer”) to passive non-responses (skip the question) increased.
To conclude, reduction of anonymity reduced responses to sensitive questions. However, it also encouraged participants to answer questions “better”. It’s interesting that such a minute detail would have a significant effect on responses to sensitive questions.
Joinson, A. N., Woodley, A., & Reips, U. (2007). Personalization, authentication, and self-disclosure in self-administered Internet surveys. Computers in Human Behavior 23(1), 275-285. [PDF]