The growth curve model in statistics is a specific multivariate linear model, also known as GMANOVA (Generalized Multivariate Analysis-Of-Variance). [1] It generalizes MANOVA by allowing post-matrices, as seen in the definition.
Growth curve model: [2] Let X be a p×n random matrix corresponding to the observations, A a p×q within design matrix with q ≤ p, B a q×k parameter matrix, C a k×n between individual design matrix with rank(C) + p ≤ n and let Σ be a positive-definite p×p matrix. Then
defines the growth curve model, where A and C are known, B and Σ are unknown, and E is a random matrix distributed as Np,n(0,Ip,n).
This differs from standard MANOVA by the addition of C, a "postmatrix". [3]
Many writers have considered the growth curve analysis, among them Wishart (1938), [4] Box (1950) [5] and Rao (1958). [6] Potthoff and Roy in 1964; [3] were the first in analyzing longitudinal data applying GMANOVA models.
GMANOVA is frequently used for the analysis of surveys, clinical trials, and agricultural data, [7] as well as more recently in the context of Radar adaptive detection. [8] [9]
In mathematical statistics, growth curves such as those used in biology are often modeled as being continuous stochastic processes, e.g. as being sample paths that almost surely solve stochastic differential equations. [10] Growth curves have been also applied in forecasting market development. [11] When variables are measured with error, a Latent growth modeling SEM can be used.
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