Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Use of the score test as a goodness-of-fit measure of the covariance structure in genetic analysis of longitudinal data | 185 Genet Sei. Evol. 35 2003 185-198 INRA EDP Sciences 2003 DOI gse 2003003 Original article Use of the score test as a goodness-of-fit measure of the covariance structure in genetic analysis of longitudinal data Florence Jaffrezica b Ian . Whitea Robin Thompson0 a Institute of Cell Animal and Population BiologY UniversitY of Edinburgh West Mains Rd. Edinburgh EH9 3JT UK b Station de génétique quantitative et appliquée Institut national de la recherche agronomique 78352 JouY-en-Josas Cedex France c Rothamsted Experimental Station IACR Harpenden Herts AL5 2JQ UK and Roslin Institute Edinburgh Roslin Midlothian EH25 9PS UK Received 13 MaY 2002 accepted 7 August 2002 Abstract - Model selection is an essential issue in longitudinal data analysis since many different models have been proposed to fit the covariance structure. The likelihood criterion is commonly used and allows to compare the fit of alternative models. Its value does not reflect however the potential improvement that can still be reached in fitting the data unless a reference model with the actual covariance structure is available. The score test approach does not require the knowledge of a reference model and the score statistic has a meaningful interpretation in itself as a goodness-of-fit measure. The aim of this paper was to show how the score statistic may be separated into the genetic and environmental parts which is difficult with the likelihood criterion and how it can be used to check parametric assumptions made on variance and correlation parameters. Selection of models for genetic analysis was applied to a dairy cattle example for milk production. genetic longitudinal data analysis score test goodness-of-flt measure covariance structure 1. introduction The analysis of longitudinal data in genetic studies is attracting increasing attention. Examples in plant and animal breeding are growth curve analyses 12 or production curves for daily lactation yields for dairy cattle 10 . .
