Definition
Data carries two distinct meanings in legal contexts, one historical and one modern.
1. (Historical — Old Practice and Conveyancing) The date of a deed or other instrument; the time when it was given, that is, formally executed. In early practice, data referred specifically to the dating clause of a legal document — the moment of legal delivery or execution, not merely its calendar inscription. The word appears in formal Latin instruments, including the dating formula of Magna Carta itself.
2. (Modern — General Legal Usage) Facts, figures, recorded observations, or digital information from which conclusions may be drawn or upon which legal rights, duties, or liability may rest. In contemporary law, data operates across an expanding range of legal contexts: evidence law (facts or data underlying expert opinion), privacy and cybersecurity law (personal and sensitive information held by organizations), regulatory compliance (data retention, data localization, data minimization requirements), and intellectual property (database protections). No single statutory definition governs across all of these areas; the operative definition of data shifts depending on the legal framework in question.
Common Language
Modern common usage (Wiktionary): Plural of datum; a collection of facts or measurements.
Historical common usage (Webster's 1913): See datum — a given fact or starting point for reasoning.
The gap between common and legal meaning is not one of opposition but of precision and consequence. Ordinary usage treats data as a neutral plural noun — collected information. Legal usage increasingly attaches rights, duties, and liabilities to data as a category. Whether a particular type of information qualifies as "data" under a given statute or regulation — and what protections or obligations follow — is a legal question that the common definition does not resolve.
Common Confusion
The historical legal meaning (data as the date of a deed) is entirely distinct from the modern legal meaning (information as a legal asset or subject of regulation). Researchers encountering data in pre-modern legal instruments, particularly in Latin-language documents, should read it as referring to execution date, not to information. The two meanings share only etymology, not function.
Data and datum occasionally cause confusion in evidence contexts. Federal Rule of Evidence 703 uses the phrase "facts or data" as a term of art governing the bases of expert opinion. In that context, data is not a technical term of art separate from facts but serves alongside it to capture the full range of information an expert may rely upon.
Why It Matters in Research
The historical meaning is a trap for the unwary. A researcher encountering data per manum in a medieval or early modern instrument is reading a dating clause, not a reference to information. Burrill's entry is the most useful guide here, preserving the full Latin formula and its translation. Missing this distinction can produce misreadings of instrument execution dates.
The modern legal meaning, by contrast, is a rapidly evolving area where no single corpus entry or dictionary definition can be relied upon without checking the governing statutory or regulatory framework. The definition of data under a state breach notification statute may differ materially from the definition under a federal privacy regulation or an evidence rule. Researchers should treat each occurrence of data in a modern legal instrument as requiring definition-checking within that instrument's framework.
In evidence research, the Rule 703 context is the most structurally precise: facts or data is a paired term of art, and the distinction between admissible facts and inadmissible data (data the expert relied on but which is not itself admissible) is a recurring litigation issue. The Civil Procedure & Evidence Encyclopedia entry on Rule 703 addresses this directly.
For employment and cybersecurity researchers, data is the load-bearing term in breach notification law. State statutes vary substantially on what categories of personal information constitute protected data triggering notification obligations — name plus financial account number, biometric information, health records, and similar combinations each carry different treatment across jurisdictions.
Historical Dictionary Support
All three historical sources agree precisely on the old practice meaning: data is the date of a deed, the time of its execution. Black's (both editions) and Burrill are consistent. Burrill adds the most value by reproducing the Magna Carta formula — DATA per manum nostram — demonstrating the term in authoritative use and translating it as "given by our hand." This grounds the word in its Latin origin (dare, to give) and explains why the dating clause of a deed was called the data: the deed was given, delivered, at that moment.
All three sources also note the secondary meaning — grounds whereon to proceed; facts from which to draw a conclusion — in identical or near-identical language. This secondary meaning is the ancestor of the modern usage, though none of the historical sources anticipates the digital and regulatory dimensions that now dominate the term's legal significance. Historical dictionaries are of limited use for modern data law research beyond confirming the term's pre-digital baseline.
Jurisdictional Note
In U.S. data breach and privacy law, no uniform federal definition of data governs all contexts. State breach notification statutes — all fifty states have enacted them — vary in their definitions of protected personal information, triggering thresholds, and notification timelines. Researchers cannot assume a definition drawn from one state's statute applies in another.
Encyclopedia Cross-Reference
Data Breach and Cybersecurity Torts — The Law Mind Torts & Personal Injury Encyclopedia
Data Breach Notification and Employee Personal Information — The Law Mind Employment & Labor Law Encyclopedia
Rule 703 (Facts or Data Not Admissible) — The Law Mind Civil Procedure & Evidence Encyclopedia