What does categorisation mean?
Categorisation is the process of sorting things — objects, ideas, people, data — into groups or classes according to features they share. As a noun, it can mean the activity itself, as in 'the categorisation of species,' or a specific resulting scheme, as in 'a useful categorisation of learning styles.' It is a workhorse word in academic writing, information science, business, and everyday organisation: libraries rely on it, machine-learning systems perform it automatically, and tax authorities require careful categorisation of expenses. Its connotations are neutral to positive, suggesting order, clarity, and systematic thinking, though critics sometimes warn that over-eager categorisation flattens nuance. British English spells it with an s (categorisation), while American English prefers z (categorization). Derived forms include the verb categorise and the adjective categorical, which carries a distinct, stricter meaning of absolute or unqualified. Understanding categorisation helps in reading research, policy documents, and any text that organises the world into named kinds.
The action or process of classifying things according to shared characteristics.
"Careful categorisation of the specimens took the researchers several weeks."
Often followed by 'of' to specify what is being classified.
A particular classification, or a system of categories, produced by this process.
"Her paper proposes a new threefold categorisation of urban neighbourhoods."
In this sense it frequently appears with modifiers such as 'simple', 'binary', or 'five-fold'.
The plural refers to multiple acts of classifying or multiple distinct classification schemes; it is relatively uncommon outside academic and technical writing.
"Different disciplines favour different categorisations of the same phenomena."
Every time you sort your inbox or shelve a book by genre, you're performing an act that philosophers from Aristotle onward have treated as one of the foundations of human thought.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of categorisation
Categorisation derives ultimately from the Greek katēgoria, meaning 'accusation' or 'predicate,' formed from kata ('against' or 'down') and agoreuein ('to speak in the assembly'). Aristotle used katēgoriai to name his fundamental classes of being, giving the root its enduring philosophical sense. The term passed into Latin as categoria and entered English in the late Middle Ages, with the noun category established by the early modern period. Categorisation itself is a much later formation, combining category with the Latinate suffix -isation, and its sibling spellings reflect the broader British -ise versus American -ize divide.
Related word forms
How categorisation is actually used
Categorisation is the standard spelling in British English; American English typically uses categorization. The word is neutral in tone and common in academic, technical, and organisational contexts. It is often used with 'of' (the categorisation of documents) and can refer either to the activity or to a particular resulting scheme.
Easily confused with categorisation
Categorisation is simply the British spelling with -s-, while categorization is the American spelling with -z-; the meanings are identical.