goodness-of-fit
UK[ˌɡʊdnəs əv ˈfɪt]US[ˌɡʊdnəs əv ˈfɪt]
n
a measure of how well a statistical model matches the data it is intended to represent.
n
the degree to which a theoretical distribution or a set of predicted values corresponds to observed data.
Morpheme Breakdown
goodness
of
fit
goodness
of
fit
Etymology
the compound term "goodness-of-fit" is a modern statistical construction built entirely from native english lexical elements. the core concept, "fit," meaning suitability or correspondence, was joined with the abstract noun "goodness," denoting the quality or degree of being good, via the relational preposition "of." this syntactic phrase was lexicalized in the early 20th century within the specialized field of statistics to name a precise quantitative measure. its logic is transparently literal: it describes the "goodness" (quality or degree) "of" the "fit" (correspondence) between a model and observed data, translating an abstract mathematical assessment into familiar english terms.
Analysis
Structure: goodness + of + fit
goodness: from old english 'gōdnes' (goodness, virtue, excellence), derived from 'gōd' (good). functions as a noun-forming suffix '-ness' added to the adjective 'good'.
of: from old english 'of', a preposition indicating origin, separation, or relation.
fit: from middle english 'fitten' (to be suitable, to arrange), of uncertain origin, possibly from old norse or middle low german. functions as a noun in this compound.
Examples
the chi-squared test is commonly used to assess the goodness-of-fit of a model.
a high p-value indicates a good goodness-of-fit between the observed frequencies and the expected distribution.
researchers evaluated the goodness-of-fit indices before accepting the proposed structural equation model.