How to ensure anonymity in an online employee survey?

In employee surveys, there is often the possibility that respondents will not answer honestly, because of the fear that their responses will not remain anonymous. Employers can provide anonymity in various ways:

• We use trusted software. Employees must trust, that the tool through which they are filling in the survey will not allow linking between identifiers and responses (ID and responses must be stored in different files).
• We avoid individualized URLs in the survey, as the respondents can notice it. In case that we do not use individualized URLs, it is reasonably also to emphasize it in the survey invitation, for example: ''We ensure you complete privacy of your responses, so the survey URLs are not individualized …'' This can contribute to a significantly higher level of responses, since many respondents are increasingly disturbed by the fact that they receive an individualized URL, knowing that this in principle allows also insights into individual's responses.
• Through a trusted person (courier, secretaries) that delivers envelopes with access code to the employees in the offices (or they are prepared at the central administrative desk – e.g. at the secretary's office) where the employees can pick them up). This makes it an elegant way to avoid duplicated or uninvited responses, while still ensuring complete anonymity, as the URL is also unified for all respondents. More >>

Additionally, it is necessary to ensure that IP addresses and other paradata are not archived.