curvilinear trend


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curvilinear trend

Etymology: L, curvus, bent, linea, line; AS, trendan, to turn
(in statistics) a trend in which a graphic representation of the data yields a curved line. The value of the independent variable may be expressed as a polynomial coefficient; by a more complete mathematic expression, such as a logistic curve; or by a smoothing process, such as a moving average.
References in periodicals archive ?
Regression models were used to estimate the two separate portions of the overall curvilinear trend.
Trends based on the stronger of three or four years of history diminish linear effects, as do polynomials that establish curvilinear trends.
So will using a polynomial trending that will seek out curvilinear trends.
The current paper demonstrates that when multicollinearity exists and the true model does not include curvilinear trends, adding quadratic terms does increase the probability of type II error in detecting interaction.
The 11 averages (1 average/yr) for each treatment in each field were analyzed to determine whether there were linear or curvilinear trends between average PS and time.