====== Personalized Links and Participation Codes ======

You can provide a questionnaire either via a non-personalized, public link on the internet, or you can use personalized links.


==== Public URL ====

Any Person (or bot) who knows the link to the survey can access and complete it. 

  * Public links are suitable for convenience samples and for
  * surveys where the link is shared within a small group, and where, for example, due to the short survey period, there is little risk that third parties will influence or disrupt the study. For example:
      * Feedback immediately after an event or a seminar, or
      * collecting ideas for an event at a daycare center or preschool.

You can find the public URL of the questionnaire in the **Project Settings** (gear icon in the top right corner) under the tab “Publish questionnaire”.

==== Public URL with Access Restrictions ====

Under **Create Questionnaire** in the “Access” tab, you can restrict access to the questionnaire ([[:en:create:access]]).

If respondents are not known by name in advance (e.g., via email addresses), two restrictions are available:

  * Restriction to specific IP ranges, for example, to the intranet of a university or a company.
  * Restriction via campus/company login (Single Sign-On). When accessing the questionnaire, users are redirected to a login platform (Identity Provider, IdP), and completion is only possible after a successful login.

**Note:** The Single Sign-On login option can only be selected if you are also logged into SoSci Survey via Single Sign-On.

The use cases for Single Sign-On (SSO) are similar to those for logging in with an email address and password (below).


==== Personalized Links =====

Common reasons for using personalized links include:

  * Restricting access to predefined individuals.
  * Reliably preventing multiple participation by individuals or bots ([[:en:survey:unique-respondents]]).
  * Longitudinal studies ([[:en:create:waves]]).
  * Importing external data ([[:en:create:functions:paneldata]] -> Import data).

**Important:** Depending on configuration, the use of personalized links may result in the collection of personal data, which entails specific obligations under EU law. Please read the notes in the [[:en:general:dsgvo]] guide.


===== Types of Personalized Links =====

SoSci Survey offers numerous options for personalized participation for various purposes.

For a better understanding of how personalized links are structured, please read the first paragraphs of the guide [[:en:survey:url]].

==== Link Tagging ====

When you send a survey link to a group or an individual, you can add a tag to the link. For example, if the survey is accessible at %%https://www.soscisurvey.de/example/%%, you can tag the link with the parameter ‘'r’':

%%https://www.soscisurvey.de/example/?r=Code001%%

The text ‘'Code001’' is chosen arbitrarily here and appears as the variable REF in the data record when the link is accessed.

**Important:** If the link to the questionnaire already contains other parameters, the ‘'r’' parameter is appended with an ampersand (&) instead of a question mark (?), e.g.

%%https://www.soscisurvey.de/example/?act=VSG4KK74SD85DG72&r=Code001%%

**Important:** Set the access mode to “public” under **Compile Questionnaire** (this is the default setting) so that the links work.

**Important:** A tag does not constitute access protection; third parties can access and complete the questionnaire regardless of the tag if they know the link.

  * Uses
    * Assigning cases to individual people or groups of people
    * Multiple entries allowed
  * Limitations
    * When used for individual people, likely to involve personal data
    * Multiple entries allowed
    * Participants can manipulate the tags
    * No access restrictions
    * Cannot pause and resume while filling out the form (at least not via the link)

If you expect that people might try to see if other codes work (they do), then do not use codes that are easy to guess; instead, use random codes. For example, you can generate random alphanumeric codes under **Send Invitations** -> **Participation Codes**.
 

==== Participation URLs ====

A participation URL supplements the link to the questionnaire with a long random code consisting of letters and numbers (“token”), which is included as the parameter ‘'d’' in the link, e.g.

%%https://www.soscisurvey.de/example/?d=AMHJYCSH6NYVWRDU%%
    
SoSci Survey maintains a list of tokens that grant access to the questionnaire. You can create valid links under **Send Invitations** -> **Participation Links**. You will then receive the links as an Excel list. You can create multiple link lists and specify for each one which questionnaire (if there are multiple in the project) the link leads to and whether single or multiple participation is allowed.

**Important:** To ensure that participation is only possible via valid links, select the “Mass email / Participation URL” option under **Create Questionnaire** in the “Access” tab.

**Important:** Participation URLs are designed to ensure a high degree of anonymity. It is not possible to determine which link corresponds to which data record. Even if you allow multiple submissions, you cannot (!) identify in the dataset which cases were completed via the same link.

  * Uses
    * Prevent multiple participation
    * Anonymity
    * Allows for pausing and resuming while filling out the survey
    * External data can be imported using [[:en:create:databank]]
  * Limitations
    * Not suitable for longitudinal studies
    * No linkage to individuals or email addresses possible


==== Mass Emails ====

If you provide SoSci Survey with a list of email addresses, the program can automatically generate a participation URL for each address and send it to that address.

A detailed description of this feature can be found in the guide [[:en:survey:mailing:sosci]].

Unlike participation URLs (above), the mass email feature also optionally allows for personally identifiable participation and/or pseudonymous assignment in longitudinal studies. Please read [[:en:survey:mailing:privacy]] for more information.

**Important:** To ensure that participation is only possible with valid links, select the O option under **Compile Questionnaire** in the “Access” tab.

   * Uses
    * Prevent multiple participation
    * Longitudinal studies
    * Anonymous, pseudonymous, or personally identifiable participation (depending on settings)
    * Allows for pausing and resuming while filling out the survey
    * External data can be imported using ‘’[[:en:create:functions:paneldata]]''
  * Limitations
    * Respondents’ email addresses required


==== Participation Codes ====

Participation codes are (relatively short) random combinations of letters and numbers, e.g., TK573855.

Respondents can either type these codes in or they can be included as part of a personalized link.

  * Option 1: You send a letter to respondents containing the link %%https://www.soscisurvey.de/example/%% and the (unique) participation code. Respondents access the link and then enter the code.
  * Option 2: You print the participation codes on small slips of paper, distribute them, and communicate the questionnaire link centrally. When accessing the link, respondents type it in from the slip of paper. This option ensures a very high degree of anonymity, for example, when surveying employees.
  * Option 3: You integrate the participation codes directly as the parameter “s” in the link and send the personalized links to the target group, e.g., %%https://www.soscisurvey.de/example/?s=TK573855%%

**Tip:** Whenever you need to share links, you can also include them as QR codes, for example in letters. Word, for instance, can also embed individual QR codes in mail merges.

**Important:** Under **Compile Questionnaire** in the “Access” tab, select one of the options “Participation Code (Save in Record)” or “Participation Code (Anonymous)” so that the questionnaire can only be completed with a valid participation code.

**Important:** Depending on access settings, direct linkage between distributed codes and dataset entries may be possible, meaning you may be dealing with personal data.

  * Uses
    * Exclude or control multiple participation
    * Depending on settings and distribution of participation codes
      * Ensuring a very high degree of anonymity __or__
      * Individual assignment of data to individuals
      * Importing external data possible via [[:en:create:databank]]
  * Limitations
    * Not suitable for longitudinal studies
    * Multiple participation depends on settings in the questionnaire


By default, it is not possible to submit the same questionnaire multiple times when using participant codes, or it is only possible if most of the questions were left unanswered during the first submission (MISSING > 50). However, the exact behavior depends on the settings under **Compile Questionnaire** in the “Access” tab under //Handling of Personalized URLs//.


====  Login with Email Address and Password ====

You can create a password for respondents in advance, or you can ask them via email to set a password. They can then use this password to access one or more questionnaires.

Participants are managed via the **Address List**, just as with mass email campaigns.

Links for initial password setup are sent via mass emails.

  * Use Cases
    * Exclude or allow multiple participation
    * Longitudinal studies
    * Access to data from previous participations
    * Entering and updating data (e.g., contact or account information)
  * Limitations
    * Handling of personal data

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Keywords: personalized links, employee survey, anonymity, multiple participation, longitudinal studies.