> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pollandroll.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Launch

> Get the URLs per sample source, understand pre-filled variables and open fieldwork.

The Launch tab brings together the URLs of all your sample sources and steers the survey status. This is where you open fieldwork.

## The URL builds itself

The launch URL is built **automatically** from the pre-filled variables present in the survey. Adding or removing a pre-filled variable updates the link. This lets you pass those variables in the link (sociodemographic data from social networks, variables from a contact file).

<Note>
  "**Pre-filled variable**" designates a **variable status**: the variable is passed in the URL and picked up on the panel side. Not to be confused with "hide the variable from the respondent", a setting specific to recodes.

  Best practice: keep the **same name** for the URL variable and the platform variable. Otherwise you create a duplicate name and the questionnaire becomes impossible to test.
</Note>

To turn a question into a pre-filled variable and understand the distinction with "hidden from the respondent", see **[Pre-filled variables](/en/questionnaire/variables-recodes-scoring)** in the Questionnaire part.

### Pre-fill answers in the URL

The **URL parameters** section of the Launch tab lists each pre-filled variable and lets you choose the value or values to pass. The **link to the live questionnaire with selected parameters** updates automatically: handy for testing a path with answers already filled in. In that link, the values to personalize for each respondent are flagged **in purple**.

The value passed is the item's **Rank** (e.g. `2`) or its **exact Label**. Depending on the question type:

* a **Single choice** question passes a single value: `NOM=2`;
* a **Multiple choice** question passes several values, chained with the syntax `NOM[]=1&NOM[]=2`.

## Open fieldwork

<Steps>
  <Step title="Check the prerequisites">
    Make sure the sample sources, the quotas and the redirections are in place.
  </Step>

  <Step title="Get the URLs">
    In the **Launch** tab, get the URL of each sample source: as many URLs as there are sample sources.
  </Step>

  <Step title="Move the status forward">
    The survey goes from **Draft** → **Pending** → **Fieldwork**. The fields to personalize per survey are flagged in purple.
  </Step>
</Steps>

## The soft launch

A soft launch means launching a small batch first, checking it, then opening fieldwork fully. It is the moment to check question bases, filters and screen outs in the [interview list](/en/collecte/liste-des-interviews).

<Note>
  In Draft and Pending, an option lets you **delete the interviews permanently** (useful for live tests). Move the survey to **Fieldwork** once it is really launched, so that you do not delete real interviews by mistake.
</Note>


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