Glossary
What is identity resolution? Deterministic vs probabilistic
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Identity resolution is the process of recognising that different identifiers, such as an email, a phone's advertising ID and a TV ID, belong to the same person or household. Deterministic resolution links IDs through shared, verified signals like a login. Probabilistic resolution infers links from patterns, extending reach where no verified signal exists.
How it works
- 1
Gather identifiers
Consented identifiers are collected from logins, apps, browsers and connected TVs.
- 2
Match deterministically
IDs that share a verified signal, such as the same hashed email, are linked with high confidence.
- 3
Extend probabilistically
Models link remaining IDs from signals such as shared networks and usage patterns, each with a confidence score.
Why it matters for advertisers
- Higher match rates when onboarding first-party data into media.
- A clear trade-off between precision (deterministic) and scale (probabilistic), chosen per campaign.
- Consistent reach and frequency across web, app and CTV.
How ROQAD does it
ROQAD runs identity resolution as infrastructure rather than a black box. Signal Boost onboards and matches your customer data; ROQAD Graph combines deterministic and probabilistic links to connect devices, IDs and households; and Zeotap Data enriches the resolved IDs with consented audience data.
Frequently asked questions
Which is better, deterministic or probabilistic?
Neither is better in every case. Deterministic links are more precise; probabilistic links add scale. Most advertisers use deterministic links as the core and probabilistic links to extend reach.
What signals are used in deterministic matching?
Typically hashed emails, logins or other verified identifiers that appear on more than one device. Because the same signal appears on each device, the link is treated as confirmed.
How is probabilistic matching kept accurate?
Models are trained and validated against deterministic links, and each inferred link carries a confidence score. Low-confidence links can be excluded for precision-sensitive campaigns.
Is identity resolution allowed under GDPR?
It can be, when it relies on consented, pseudonymised data and a documented lawful basis. ROQAD's graph is built on TCF-consented data.
How often should an identity graph be refreshed?
Frequently. IDs reset, devices change and people move, so a daily refresh keeps links current and avoids targeting stale identifiers.