Analyzing Developmental Trajectories with Mixture Models: A Second Generation of Models and Software

发展轨迹描述了一种行为随着年龄或时间的变化过程。该项目建立在美国国家科学基金会先前资助的研究(SES-9511412)的基础上，该研究开发了一种半参数、基于组的方法来识别感兴趣人群中独特的个体轨迹组，并制作了用于估计轨迹模型的基于SAS的软件。该项目将在几个重要方面扩展研究。首先，单变量弹道模型和软件将被扩展，以包括随机效果分量。该软件还将进行扩展，以纳入先前开发的非参数弹道模型。第二，将开发下一代关节轨迹模型。到目前为止，工作的重点是开发适合于分析单一行为的发展过程的基于群体的模型。这项研究的一个关键目标是推广单变量轨迹模型，以允许联合估计两种不同但相关的行为的轨迹，例如童年的身体攻击和青春期的暴力犯罪。在这里，关节弹道估计的能力将被纳入现有的软件包中。第三，将探索评估模型拟合优度的替代方法。这些措施旨在补充贝叶斯信息标准(BIC)作为模型选择的基础。这一方法论研究计划是由犯罪学、发展心理学和精神病学的实质性问题推动的，如共病和异型连续性。共病是指儿童时期同时发生两种或两种以上不良情况，如身体攻击和多动。异型连续性是指一种潜在的个体特征以不同但相似的行为形式在时间上的跨期表现。例如，潜在的暴力倾向可能表现为幼儿时期踢咬兄弟姐妹，青春期帮派打架，成年后虐待配偶。攻击的形式和目标不同，但不变的是身体暴力。由于表现形式的变化，在生命的不同阶段使用相同的测量尺度来捕捉这种趋势是不合适的。将在对来自世界各地的主要前瞻性纵向数据集的分析中探讨共发病和异型连续性的主题。

A developmental trajectory describes the course of a behavior over age or time. This project builds upon prior NSF funded research (SES-9511412) that developed a semi-parametric, group-based approach for identifying distinctive groups of individual trajectories within the population of interest, and also produced "canned" SAS-based software for estimation of the trajectory models. This project will extend the research in several important ways. First, the univariate trajectory models and software will be extended to include a random effect component. The software also will be expanded to incorporate a previously developed non-parametric trajectory model. Second, a next generation of joint trajectory models will be developed. Work to date has focused on developing group-based models appropriate for analyzing the developmental course of a single behavior. A key goal of this research is to generalize univariate trajectory models to allow the joint estimation of trajectories of two distinct but related behaviors, for example, physical aggression in childhood and violent delinquency in adolescence. Here again the capacity for joint trajectory estimation will be incorporated into the already available software package. Third, alternative measures for evaluating model goodness of fit will be explored. Such measures are intended to complement the Bayesian Information Criterion (BIC) as a basis for model selection.This methodological research program is motivated by substantive problems from criminology, developmental psychology, and psychiatry, such as co-morbidity and heterotypic continuity. Co-morbidity refers to the contemporaneous occurrence of two or more undesirable conditions such as physical aggression and hyperactivity during childhood. Heterotypic continuity refers to the inter-temporal manifestation of a latent individual trait in different but analogous behavioral forms. For example, a latent propensity for violence may reveal itself as kicking and biting siblings during early childhood, gang fighting during adolescence, and spouse abuse during adulthood. The form and target of the aggression is different but the constant is physical violence. Because of the changing form of the manifestation, use of the same measurement scale at different stages of life is inappropriate for capturing such a tendency. The themes of co-morbidity and heterotypic continuity will be explored in analyses of major prospective longitudinal data sets from around the world.