Identity Resolution vs. Identity Graph: Process vs. Asset
The difference between identity resolution and an identity graph, how resolution works step by step, and what to ask when a vendor offers either one.
The short answer
Identity resolution is the process of deciding which records refer to the same person, household, or business. An identity graph is the stored result of that process: the map of linked identifiers. Vendors often use the terms together, but buyers should evaluate both: how good the matching process is (rules, thresholds, validation) and how good the resulting graph is (coverage, accuracy, freshness, and sourcing).
"Identity resolution" and "identity graph" are often used as if they mean the same thing. They are related but different, and confusing them leads to buying the wrong thing or asking the wrong questions.
Definitions
- Identity resolution: a process. Take records from different sources and decide which ones refer to the same entity.
- Identity graph: an asset. The stored network of links between identifiers, built and updated by resolution.
A customer data platform might resolve identity across a brand's own records. A data company might maintain a large graph and sell access to it.
How identity resolution works
- Standardize. Clean names, addresses, emails, and phone numbers into consistent formats.
- Match. Compare records using rules or models. Exact matches on strong keys (hashed email, NPI) are deterministic. Similar-but-not-identical records require probabilistic scoring.
- Score and threshold. Decide how confident a match must be to link records.
- Link. Assign a persistent ID to the resolved entity.
- Maintain. Update as new data arrives and remove stale links.
Evaluating the process
| Question | Why it matters |
|---|---|
| Which match keys are used? | Strong keys produce reliable links |
| How are thresholds set? | Low thresholds raise match rates and errors |
| How is accuracy measured? | Against what truth data, how often |
| How are conflicts resolved? | Same email on two people, two NPIs for one person |
| How are links removed? | Stale links create waste |
Evaluating the graph
| Question | Why it matters |
|---|---|
| Coverage | Share of your audience that can be matched |
| Freshness | How recently links were confirmed |
| Sourcing and consent | Legal and reputational risk |
| Sensitive data handling | Especially for health |
See what an identity graph is for more on graph quality.
For HCP data
HCP identity resolution usually starts from the NPI, which is a strong key. The challenge is linking an NPI to digital identifiers. The HCP identity matching article explains how an NPI becomes addressable.
Questions to ask vendors
- Are you offering a resolution service, a graph, or both?
- Which keys and thresholds do you use for my data?
- How do you measure precision and recall of matches?
- How often is the graph refreshed?
- What data sources feed the graph, and under what consent?
Common mistakes
- Comparing vendors only on match rate.
- Not asking about thresholds.
- Assuming a CDP's resolution covers media identifiers.
- Forgetting to remove stale links.
Practical takeaway
Send the same test file to two identity vendors and ask each to report matches split by match key and confidence level. Where they disagree on the same records is where you learn which process is more careful.
Frequently asked questions
Is identity resolution the same as an identity graph?
No. Identity resolution is the matching process. The identity graph is the database of links that process produces and maintains.
Do customer data platforms do identity resolution?
Many do, mostly on a brand's own first-party data. They may connect to third-party graphs to extend matching.
What is a match key?
The identifier used to join records, such as a hashed email, postal address, or NPI.
Sources
External guidance and platform documentation change. Links were current at publication; check them again before relying on them for a decision.
Editorial note. Analysis and frameworks are the author's own and do not represent Acxiom or any current or former employer, client, or named platform. Examples labeled hypothetical or illustrative are not results from real campaigns. Nothing here is legal, regulatory, or medical advice.
New pharma programmatic breakdowns, occasionally
One email when I publish something worth reading. Benchmarks, measurement teardowns, and case studies with the caveats attached. No cadence promises, no reselling your address.
Unsubscribe any time. See the privacy policy.
Working through this decision on a real plan?
I work on health and pharma data, identity, and activation, after five years running HCP and DTC programmatic agency-side. Happy to talk through how this applies to your situation.