Serial numbers

Serial numbers are short codes that entitle you to fill out a questionnaire once. They have the following functions:

• Restriction of the group of participants.
• Prevent Multiple Submissions by the Same Respondent
• Assignment of survey data to an external data set.

Note: Under certain conditions, it is possible to fill out the questionnaire multiple times with one serial number (see Pause and Continue Questionnaire Completion). Multiple cases with the same serial number can be identified and deleted in the data cleanup using the SERIAL variable.

Note: Resuming a previously interrupted interview works regardless of whether the access restriction “serial number” was selected in the questionnaire. On the other hand, the correct access restriction must be set for the restriction of the participants and the display of a serial number query (if the serial number is not transmitted in the link).

So that SoSci Survey knows which codes (serial numbers) are valid, there are two possibilities:

1. SoSci Survey creates a list of valid serial numbers under Send Invitations → Serial Numbers.
2. One creates (outside of the program) a list of serial numbers and imports it into SoSci Survey under Send invitations → Serial numbers.

If the access restriction “serial number” (not to be confused with “serial mail”) is set for a questionnaire, then a serial number must be present in order to fill it out.

• The respondent can either type in this serial number manually,
• or the respondent will receive a link with serial number right away.

If you want to send the serial number directly in the link, it must be added as parameter “s” in the link. For more information see URL to the Questionnaire. This does not require any changes in SoSci Survey, you just need to send a supplemented link.

Serial numbers can – depending on the application – lead to obtaining personal data or to ensuring maximum anonymity.

The serial number is noted directly in the record, as a SERIAL variable.

So if you have a list of names and sent links (with serial number), then it is possible to unambiguously assign which addressee belongs to a data record based on this list.

Important: As soon as you send the links with serial numbers via e-mail, the assignment will at least be evident from the sent e-mails. It is also possible that copies of the e-mails are stored on the mail server. This data must be avoided or reliably deleted if anonymity is to be guaranteed.

Serial numbers can also be printed out – for example, on stickers that are then stuck on letters (without remembering or noting the assignment) or on slips of paper that are subsequently placed in a lottery drum.

Slips of paper in a lottery drum are particularly suitable for surveys in companies (employee surveys, customer surveys) where the addressees of the survey are personally on site. If each person draws a slip of paper from the lottery drum, anonymity is guaranteed (provided that the questionnaire does not ask for any characteristics that may indicate identity), and at the same time the following is ensured:

• Each person can fill in the questionnaire only once (unless they draw several slips from the lottery drum).
• The completion of the questionnaire can be interrupted and continued later.