Boker S M, McArdle J J
Department of Psychology, University of Virginia, Charlottesville 22903, USA.
Exp Aging Res. 1995 Jan-Mar;21(1):77-93. doi: 10.1080/03610739508254269.
Combined cross-sectional and longitudinal data often present complex patterns of change. Growth functions representing the change in some measure as a function of chronological age can be a function of initial values of the measurement. Individual differences in developmental age with respect to chronological age tend to distort attempts to fit a single growth curve through combined cross-sectional and longitudinal data. We present a method by which these data can be visualized along with several examples from a data set comprising measurements of intellectual abilities with respect to aging. We call this new method a statistical vector field (svf) plot. An svf plot simultaneously allows the visualization of cross-sectional information summarizing sampling densities and longitudinal information summarizing how individuals at each particular age and ability are likely to change over time. The C source code for the svf software described in this paper may be obtained free from the University of Virginia anonymous ftp archive server (ftp. Virginia.EDU), or from the authors.
横断面数据和纵向数据相结合时，常常呈现出复杂的变化模式。将某种测量值的变化表示为实足年龄函数的生长函数可能是该测量初始值的函数。相对于实足年龄的发育年龄个体差异往往会扭曲通过横断面数据和纵向数据相结合来拟合单一生长曲线的尝试。我们提出了一种方法，通过该方法可以将这些数据可视化，并给出了一个数据集的几个示例，该数据集包含了关于衰老的智力能力测量。我们将这种新方法称为统计向量场（svf）图。svf图同时允许可视化总结抽样密度的横断面信息以及总结每个特定年龄和能力的个体随时间可能如何变化的纵向信息。本文所述svf软件的C源代码可从弗吉尼亚大学匿名ftp存档服务器（ftp.Virginia.EDU）免费获取，也可从作者处获得。
