Threshold model

(or bell-shaped curve) where each band has a width of 1 standard deviation. If the threshold is 2 standard deviations above the mean of the latent variable, then about 2.4% of the population would have the trait. In mathematical or statistical modeling a threshold model is any model where a threshold value, or set of threshold values, is used to distinguish ranges of values where the behaviour predicted by the model varies in some important way. A particularly important instance arises in toxicology, where the model for the effect of a drug may be that there is zero effect for a dose below a critical or threshold value, while an effect of some significance exists above that value. Certain types of regression model may include threshold effects.

(or bell-shaped curve) where each band has a width of 1 standard deviation. If the threshold is 2 standard deviations above the mean of the latent variable, then about 2.4% of the population would have the trait.]] In mathematical or statistical modeling a threshold model is any model where a threshold value, or set of threshold values, is used to distinguish ranges of values where the behaviour predicted by the model varies in some important way. A particularly important instance arises in toxicology, where the model for the effect of a drug may be that there is zero effect for a dose below a critical or threshold value, while an effect of some significance exists above that value. Certain types of regression model may include threshold effects. ==Segmented regression analysis== The models used in segmented regression analysis are threshold models. ==Fractals== Certain deterministic recursive multivariate models which include threshold effects have been shown to produce fractal effects. ==Time series analysis== Several classes of nonlinear autoregressive models formulated for time series applications have been threshold models. ==Toxicology== A threshold model used in toxicology posits that anything above a certain dose of a toxin is dangerous, and anything below it safe. This model is usually applied to non-carcinogenic health hazards. Edward J. Calabrese and Linda A. Baldwin wrote: The threshold dose-response model is widely viewed as the most dominant model in toxicology. An alternative type of model in toxicology is the linear no-threshold model (LNT), while hormesis correspond to the existence of opposite effects at low vs. high dose, which usually gives a U- or inverted U-shaped dose response curve. ==Global boiling== The proposition that global temperature will rise in a non-linear mode once it crosses a hypothetical threshold value has been made in several studies Lynch & Walsh 1998, Genetics and Analysis of Quantitative Traits, "Ch25, Threshold Characters" Rijsdijk & Sham 2002, "Analytic approaches to twin data using structural equation models" Visscher & Wray 2015, "Concepts and Misconceptions about the Polygenic Additive Model Applied to Disease", Hilker et al. 2017, "Heritability of schizophrenia and schizophrenia spectrum based on the nationwide Danish Twin Register" (downward biases in liability threshold model heritability estimates due to censoring measurement error) ==References==

Text derived from https://en.wikipedia.org/w/index.php?oldid=1351320956 under CC BY-SA 4.0; modifications have been made.