Rate of genetic improvement for milk yield has been increasing in recent years. Cows born in 1986 were about 135 kg superior in breeding value for milk yield to those born in 1985. Over 2.2 million cows contribute new data to genetic evaluations for production traits annually. These evaluations are computed with an animal model that provides best linear unbiased predictions of transmitting abil...

In this paper we present a series of item response models of data collected using the Force Concept Inventory. The Force Concept Inventory (FCI) was designed to poll the Newtonian conception of force viewed as a multidimensional concept, that is, as a complex of distinguishable conceptual dimensions. Several previous studies have developed single-trait item response models of FCI data; however,...

The usefulness of genetic progress for litter size in pig breeding is limited by mothering ability and piglets survival. It is a critical aspect for breeds used as dam lines, in which litter weight (LW) at weaning could be an alternative selection goal. Our objective was to investigate the genetic basis of LW at 21days for the six first parities in 1,449 Iberian sows with available records from...

Correct and, hence, valid classifications of individuals are of high importance in the social sciences as these classifications are the basis for diagnoses and/or the assignment to a treatment. The via regia to inspect the validity of psychological ratings is the multitrait-multimethod (MTMM) approach. First, a latent variable model for the analysis of rater agreement (latent rater agreement mo...

To explain diversity in forests, niche theory must show how multiple plant species coexist while competing for the same resources. Although successional processes are widespread in forests, theoretical work has suggested that differentiation in successional strategy allows only a few species stably to coexist, including only a single shade tolerant. However, this conclusion is based on current ...

One of the key interests in the social sciences is the investigation of change and stability of a given attribute. Although numerous models have been proposed in the past for analyzing longitudinal data including multilevel and/or latent variable modeling approaches, only few modeling approaches have been developed for studying the construct validity in longitudinal multitrait-multimethod (MTMM...

Forty subjects served in a study investigating the characteristics of experimental pain measures. Subjects indicated when their pain threshold and tolerance levels had been reached with each of three stressors: cold, pressure, and electrical shock. Using the multitrait-multimethod matrix procedure, the measures of threshold and tolerance were found to show both generality and discriminant valid...