Finding duplicate users

In hroot, administrators can identify and manage duplicate participant profiles using built-in duplicate detection rules. This helps prevent participants from creating multiple accounts to bypass recruitment limits or restrictions.

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1. Where to Access Duplicate Search

There are two primary locations in hroot to manage duplicates:

1. Duplicate Users Settings: Navigate to Site Settings -> Duplicate Users (Doppelte Benutzer / /admin/options/duplicate_checks under Participants & Master Data). This allows administrators to customize, enable/disable, and configure the duplicate detection rules.
2. User Search Filters: Go to Users (/admin/users). In the filter sidebar under the Duplicate accounts (Doppelte Benutzer) section, check the respective options to filter the user list directly.

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2. Types of Duplicate Checks

The system performs three automated default matching queries (which can be customized in Site Settings):

Match Type A: Identical First & Last Names (name)

• Query Condition: Matches accounts where the First Name AND the Last Name are identical (firstname and lastname).
• Use Case: Catching simple re-registrations under the same name but using a different email address.

Match Type B: Identical Last Name & Date of Birth (birthday)

• Query Condition: Matches accounts where the Last Name AND the Date of Birth (lastname and birthday custom field) are identical.
• Use Case: Catching users who register with a slightly different first name (e.g., "John" vs. "Johnny" or "Jon") but share the same family name and birth date.

Match Type C: Identical Bank Details (iban)

• Query Condition: Matches accounts with an identical IBAN (iban).
• Use Case: Catching users who attempt to create multiple participant accounts to participate multiple times while utilizing the same bank account for payouts.

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3. Managing Duplicate Accounts

When duplicates are listed:

• Visual Indicators: Matching profiles display warning icons in the user list. Hovering over the icon displays the specific duplicate detection reason.
• Merging Accounts: Select the suspected accounts using the checkboxes in the Users overview, click Aktionen (Current result), and select Benutzer zusammenführen... (Merge Users) to inspect profile data side-by-side and merge them into a single primary account.
• Exclusion: Users who are marked as permanently deleted (anonymized/inactive) or pairs explicitly marked as "ignored duplicates" are excluded from duplicate matching.