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

# Recontact Respondents

> Target specific prior respondents for follow-up surveys using RDUD lists.

**Recontact Respondents** lets you reach eligible respondents from a prior study for follow-up questions. Only specified RDUDs are allowed to participate.

This feature is separate from [sample exclusions](/research-desk/guides/06-sample-exclusions), which block prior participants from entering.

## Finding RDUDs to target

### From Research Desk

1. Open the original project that collected the respondents you want to recontact
2. Export the **Traffic Report**
3. Filter to the desired respondents
4. Copy the list of RDUDs

### From your survey platform

1. Confirm the variable that captured `[%RDUD%]` from the survey URL
2. Export respondent data including that variable
3. Filter to the desired respondents
4. Copy the list of RDUDs

## Configuring recontact targeting

1. Open the **Qualifications** panel in your new source
2. Search for **Recontact** or scroll to **Advanced Recruitment Methodology**
3. Select **Recontact Respondents**
4. Paste your RDUD list
5. Click **RDUD Lookup** to validate eligibility

### RDUD lookup statuses

| Status                                          | Meaning                                                                          |
| ----------------------------------------------- | -------------------------------------------------------------------------------- |
| **Eligible**                                    | Respondent confirmed; recontact information available                            |
| **Ineligible — Unavailable for recontact**      | Respondent found but recontact data unavailable                                  |
| **Ineligible — Respondent with multiple RDUDs** | Multiple RDUDs map to one individual; most recent is Eligible, others Ineligible |
| **Ineligible — RDUD not found**                 | RDUD does not exist or is outside the permitted time frame                       |

6. Confirm the eligible count and launch when ready

## Passing the original RDUD (ORDUD)

You must always pass a **new** RDUD on the entry link, even when recontacting. To link back to the original session, also pass the original RDUD as **ORDUD**.

Example entry link:

```
https://your-survey.com/start?rdud=[%RDUD%]&ordud=[%ORDUD%]
```

On Decipher, you might capture ORDUD as a separate embedded data field from the recontact qualification.

## Post-field verification

The traffic report for a recontact study includes an **ORDUD** column, making it easy to match responses across surveys even if ORDUD was not passed in the survey URL.

## Related guides

* [Exporting and Reporting](/research-desk/guides/12-exporting-and-reporting)
* [Entry Links and Redirects](/research-desk/guides/04-entry-links-and-redirects)