datum
Low (largely restricted to academic, technical, and formal registers).Formal, Technical, Academic
Definition
Meaning
A single piece of information, fact, or statistic; a given.
In technical contexts (e.g., surveying, engineering, geodesy), a reference point, line, or surface used as a basis for measurements or calculations.
Linguistics
Semantic Notes
While the singular is 'datum', in modern English the word is overwhelmingly used in its plural form 'data', which is now commonly treated as a mass noun (e.g., 'the data is'). The singular 'datum' is rarely encountered outside specific technical fields.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. The singular form is equally rare and technical in both varieties.
Connotations
Highly formal, academic, or precise; can sound pedantic or archaic if used in general contexts where 'data point' or 'piece of data' would be more natural.
Frequency
Extremely low frequency in both varieties. More likely to be found in British academic writing in fields like philosophy or classical studies, but this is marginal.
Vocabulary
Collocations
Grammar
Valency Patterns
serve as a datum for + NOUNuse X as a datumestablish a datumbased on the datum that + CLAUSEVocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “[No common idioms for this rare singular form]”
Usage
Context Usage
Business
Virtually never used. 'Data point' or 'metric' is preferred.
Academic
Used occasionally in technical writing in geography, surveying, engineering, and classical studies to denote a single reference value or fact.
Everyday
Extremely rare and unnatural. 'Piece of data' or 'fact' is used.
Technical
The primary domain of use, specifically in surveying, cartography, geodesy, and engineering to mean a reference for measurement.
Examples
By Part of Speech
verb
British English
- [The verb form does not exist for 'datum']
American English
- [The verb form does not exist for 'datum']
adverb
British English
- [No adverbial form]
American English
- [No adverbial form]
adjective
British English
- [No direct adjectival form. 'Datum' is used attributively, e.g., 'datum point'.]
American English
- [No direct adjectival form. 'Datum' is used attributively, e.g., 'datum line'.]
Examples
By CEFR Level
- [Too rare and technical for A2 level]
- The scientist recorded every single datum carefully in her notebook.
- This fact is an important datum for our report.
- The surveyor established a permanent datum from which all subsequent elevations were measured.
- Each interview transcript provided a valuable datum for the qualitative analysis.
- The geodetic datum for the map, based on the 1984 World Geodetic System, ensures global positional accuracy.
- Critiquing the theory, he argued that the author's entire premise rested on one unverified historical datum.
Learning
Memory Aids
Mnemonic
Think of 'datum' as the 'atom' of data – a single, indivisible unit of information.
Conceptual Metaphor
INFORMATION IS A BUILDING / A datum is a FOUNDATION STONE (a fixed point upon which other measurements/knowledge are built).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating Russian 'данные' (which is plural) as 'datum'. Use 'data'.
- The Latin plural '-a' ending can be misleading. 'Datum' is singular, 'data' is plural, but 'data' is now commonly used as a singular mass noun.
Common Mistakes
- Using 'datum' in everyday speech (sounds stilted).
- Treating 'data' as exclusively plural and forcing agreement with plural verbs in all contexts (now considered overly formal by many).
- Using 'datums' as a plural (acceptable but rare; 'data' is the standard plural).
Practice
Quiz
In which context is the singular noun 'datum' MOST likely to be used correctly?
FAQ
Frequently Asked Questions
Almost never. In general contexts, people say 'a piece of data', 'a data point', or simply 'data' (treated as a mass noun). 'Datum' is highly technical.
The traditional plural is 'data', from Latin. In technical fields, the Anglicized plural 'datums' is sometimes used, especially when referring to multiple reference points (e.g., 'several geodetic datums'), but 'data' remains far more common.
This is a stylistic choice. In modern English, especially in IT, science, and general use, 'the data is' (treating 'data' as a mass noun) is standard. 'The data are' (treating it as a plural) is more formal and traditional, and is still preferred in some academic disciplines.
In technical fields like surveying, a 'datum' is a foundational reference. In statistics and general use, a 'data point' is one individual observation or measurement in a collection of data. They are often used interchangeably in non-technical contexts, but 'data point' is the much more common term.