A theoretical evaluation of linearity.

M H Kroll; K Emancipator

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PubMed · 8448849

A theoretical evaluation of linearity.

M H Kroll·K Emancipator

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Abstract

The measure of linearity is an important part of the evaluation of a method. According to the NCCLS guidelines (Document EP6-P), results of a linearity experiment are fit to a straight line and judged linear either by visual evaluation, which is subjective, or by the lack-of-fit test. This approach depends on the precision of the method, is not necessarily conclusive, and fails to be quantitative. We define linearity as a measure of how well a first-order (linear) polynomial fits the data compared with a higher-order (nonlinear) polynomial. The major property of a linear polynomial is that the first derivative is a constant. The nonlinearity of a method can be measured by the difference between these two polynomials (first-order and higher-order) at specific values or, as an average, the root-mean difference. This approach is independent of the precision of the assay and is conclusive, quantitative, and objective.

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M H Kroll, K Emancipator. 1993. A theoretical evaluation of linearity.. https://pubmed.ncbi.nlm.nih.gov/8448849/

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