Fitting

Fitting is a term used in several disciplines to describe the process of making something suitable or properly matched for a purpose. It can refer to tailoring and garment construction, hardware and piping connections, and the statistical or computational process of aligning a model with data.

In clothing, a fitting is a session in which a dressmaker or tailor tries a garment on the client, takes measurements, and makes adjustments to size, shape, drape, or length. It may involve altering seams, adding darts, letting out fabric, or adjusting zippers. Fitting is iterative and may require multiple fittings before completion. Patterns are adjusted to better reflect the wearer’s measurements and style preferences.

In construction and plumbing, a fitting is a component used to join pieces of pipe or tubing, such as elbows, tees, couplings, or adapters. Fittings come in various materials and connection methods (soldered, threaded, compression). In mechanical engineering, fit also describes the clearance or interference between mating parts, governed by tolerances: clearance fits provide space, interference fits require deformation to assemble.

In statistics and data analysis, fitting means estimating the parameters of a model to best explain observed data. Common methods include least squares for linear relationships and maximum likelihood for probabilistic models. Curve fitting aims to discover a function that approximates the data. Issues include overfitting, underfitting, and validating model performance with new data.

The term fitting is also used more broadly to denote suitability or appropriateness, as in a fitting tribute, or a fitting choice, depending on context.