Glossary /
Data Dictionary
Efficiency & cost
Data Dictionary
One agreed definition for every metric and dimension—so the same number means the same thing to everyone.
Attribution & Measurement
Unit Economics
Data Governance & Nomenclature
Creative & Delivery
Audiences & Targeting
Mobile & Privacy
A data dictionary is a shared, governed registry of definitions for every metric and dimension in your reporting—what each one means, how it's calculated, and which inputs it draws on. It's the source of truth that keeps numbers consistent across teams.
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What is Data Dictionary?
Most reporting disputes aren't about math—they're about definitions. Does "conversion" include view-throughs? Is "ROAS" gross or net of fees? Which region does "EMEA" actually contain? When those answers live in people's heads, two correct reports can show two different numbers and nobody can say which is right. A data dictionary writes the answers down. For every metric and dimension, it records the agreed definition, the formula, the source fields, and any caveats. Once it exists, "blended CPA" or "funnel stage" means exactly one thing across the marketing org, finance, and leadership. This matters most across channels. Google, Meta, and TikTok each define conversions and values their own way, so a cross-channel number is only trustworthy if there's an agreed standard sitting above the platforms. The data dictionary is that standard—the contract everyone reports against.
How Data Dictionary differs across ad platforms
Google Ads
Google has its own definitions for conversions, conversion value, and attribution windows. Taken alone, those become the de facto "truth" for Google data—but they don't match how Meta or TikTok define the same words, so a shared dictionary is needed to reconcile them.
Meta
Meta counts and names conversions differently and uses its own attribution model. Without a dictionary that maps Meta's terms to your agreed definitions, "conversions" silently means something different the moment you cross from Google into Meta.
TikTok
TikTok adds a third vocabulary for events, values, and dimensions. Three platforms means three native glossaries; a data dictionary is what forces them into one agreed set of definitions you can report against consistently.
Common Data Dictionary misconceptions
A data dictionary is just documentation nobody reads.
A passive doc is documentation. A governed data dictionary is enforced—definitions are wired into how metrics are calculated, so the agreed meaning is what actually shows up in reports, not just what's written down.
We don't need one because everyone already knows what the metrics mean.
"Everyone knows" is exactly how you get three versions of CPA. Definitions drift quietly across teams and platforms—the dictionary makes the agreement explicit and catches the divergence before it reaches a deck.
Related Terms
Frequently Asked Questions
What is Data Dictionary in simple terms?
A data dictionary is a shared list that spells out exactly what every metric and dimension means—how it's calculated and what counts. It's so that when someone says "conversions" or "ROAS," everyone is talking about the same number.
How does Data Dictionary work?
Why does Data Dictionary differ across ad platforms?
How does Clarisights report on Data Dictionary?
Attribution & Measurement
Unit Economics
Data Governance & Nomenclature
Creative & Delivery
Audiences & Targeting
Mobile & Privacy
A data dictionary is a shared, governed registry of definitions for every metric and dimension in your reporting—what each one means, how it's calculated, and which inputs it draws on. It's the source of truth that keeps numbers consistent across teams.
?
?
What is Data Dictionary?
Most reporting disputes aren't about math—they're about definitions. Does "conversion" include view-throughs? Is "ROAS" gross or net of fees? Which region does "EMEA" actually contain? When those answers live in people's heads, two correct reports can show two different numbers and nobody can say which is right. A data dictionary writes the answers down. For every metric and dimension, it records the agreed definition, the formula, the source fields, and any caveats. Once it exists, "blended CPA" or "funnel stage" means exactly one thing across the marketing org, finance, and leadership. This matters most across channels. Google, Meta, and TikTok each define conversions and values their own way, so a cross-channel number is only trustworthy if there's an agreed standard sitting above the platforms. The data dictionary is that standard—the contract everyone reports against.
How Data Dictionary differs across ad platforms
Google Ads
Google has its own definitions for conversions, conversion value, and attribution windows. Taken alone, those become the de facto "truth" for Google data—but they don't match how Meta or TikTok define the same words, so a shared dictionary is needed to reconcile them.
Meta
Meta counts and names conversions differently and uses its own attribution model. Without a dictionary that maps Meta's terms to your agreed definitions, "conversions" silently means something different the moment you cross from Google into Meta.
TikTok
TikTok adds a third vocabulary for events, values, and dimensions. Three platforms means three native glossaries; a data dictionary is what forces them into one agreed set of definitions you can report against consistently.
Common Data Dictionary misconceptions
A data dictionary is just documentation nobody reads.
A passive doc is documentation. A governed data dictionary is enforced—definitions are wired into how metrics are calculated, so the agreed meaning is what actually shows up in reports, not just what's written down.
We don't need one because everyone already knows what the metrics mean.
"Everyone knows" is exactly how you get three versions of CPA. Definitions drift quietly across teams and platforms—the dictionary makes the agreement explicit and catches the divergence before it reaches a deck.
Related Terms
Frequently Asked Questions
What is Data Dictionary in simple terms?
A data dictionary is a shared list that spells out exactly what every metric and dimension means—how it's calculated and what counts. It's so that when someone says "conversions" or "ROAS," everyone is talking about the same number.
How does Data Dictionary work?
Why does Data Dictionary differ across ad platforms?
How does Clarisights report on Data Dictionary?
See Viewable Impression across every channel in one report
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