Truncation

Truncation refers to the act of shortening something by removing a part. The term is used across disciplines to describe processes that reduce length, size, or scope, often to fit constraints, simplify analysis, or model observations that are inherently limited.

In mathematics and statistics, numerical truncation means discarding digits beyond a chosen point in a number rather than rounding. Truncated distributions arise when data are observed only within a bounded range and are renormalized; for example, a truncated normal distribution is a normal distribution restricted to an interval.

In geometry, truncation is a construction that cuts off the vertices of a polyhedron with a plane, producing a new face at each cut; the resulting solids are called truncated polyhedra and often have regular polygon faces, with famous examples such as the truncated tetrahedron and the truncated icosahedron.

In computing, truncation commonly refers to shortening a string to a maximum length, often by removing characters from the end. It can occur due to fixed field lengths, file system limits, or data type constraints, and may lead to loss of information. Database systems also use truncation when values exceed defined column widths.

In biology and genetics, truncating mutations introduce premature stop codons, yielding shortened proteins and often loss of function.

In linguistics, truncation may describe clipping or shortening a word, though clipping is the more common term.