Participant metadata

This page lists what an interview records about its participant: the fields Pillow captures automatically and the custom values you pass in the study link. All of them appear in the interview’s Metadata panel. To add custom values to a link, see Pass participant data in the link.

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Fields Pillow records automatically

A field Pillow can’t determine shows Unknown.

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Custom parameters

Any link parameter that starts with meta_ is saved as a custom field. Pillow removes the prefix and keeps the rest of the key as you typed it, so meta_user_id=usr_48213 becomes user_id with the value usr_48213. The prefix is not case-sensitive: META_source also works. Values are stored as text. If a key appears twice, the last value wins.

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When metadata is captured

• Metadata is saved once, when the participant starts the interview. It can’t be edited afterwards.
• A participant who reopens the link in the same browser within 30 days returns to their existing interview, which keeps the metadata from their first visit, whatever parameters the second link carries.

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Other link parameters

pillow_locale sets the interview language, for example pillow_locale=fr-FR. See Supported languages. Parameters that start with dp_ or pillow_ are reserved for Pillow. Use meta_ for your own data.