Diversity and host assemblage of avian haemosporidians in different terrestrial ecoregions of Peru.

Characterizing the diversity and structure of host-parasite communities is crucial to understanding their eco-evolutionary dynamics. Malaria and related haemosporidian parasites are responsible for fitness loss and mortality in bird species worldwide. However, despite exhibiting the greatest ornithological biodiversity, avian haemosporidians from Neotropical regions are quite unexplored.

The problem of measurement bias in comparing selected subgroups.

Estimates of subgroup differences are routinely used as part of a comprehensive validation system, and these estimates serve a critical role, including evaluating adverse impact. Unfortunately, under direct range restriction, a selected mean ( ) is a biased estimator of the population mean as well as the selected true score mean . This is due partly to measurement bias.

Estimating Incremental Validity Under Missing Data.

A common form of missing data is caused by selection on an observed variable (e.g., Z).

Model Conditioned Data Elasticity in Path Analysis: Assessing the "Confoundability" of Model/Data Characteristics.

Much research has been directed at the validity of fit indices in Path Analysis and Structural Equation Modeling (e.g., Browne, MacCallum, Kim, Andersen, & Glaser, 2002 ; Heene, Hilbert, Draxler, Ziegler, & Bühner, 2011 ; Hu & Bentler, 1999 ; Marsh, Hau, & Wen, 2004 ).

What counts as evidence for working memory training? Problems with correlated gains and dichotomization.

The question of whether computerized cognitive training leads to generalized improvements of intellectual abilities has been a popular, yet contentious, topic within both the psychological and neurocognitive literatures. Evidence for the effective transfer of cognitive training to nontrained measures of cognitive abilities is mixed, with some studies showing apparent successful transfer, while others have failed to obtain this effect. At the same time, several authors have made claims about both successful and unsuccessful transfer effects on the basis of a form of responder analysis, an analysis technique that shows that those who gain the most on training show the greatest gains on transfer tasks.

Revisiting Case IV: a reassessment of bias and standard errors of Case IV under range restriction.

In 2004, Hunter and Schmidt proposed a correction (called Case IV) that seeks to estimate disattenuated correlations when selection is made on an unmeasured variable. Although Case IV is an important theoretical development in the range restriction literature, it makes an untestable assumption, namely that the partial correlation between the unobserved selection variable and the performance measure is zero. We show in this paper why this assumption may be difficult to meet and why previous simulations have failed to detect the full extent of bias.

Bootstrapping to test for nonzero population correlation coefficients using univariate sampling.

This article proposes 2 new approaches to test a nonzero population correlation (rho): the hypothesis-imposed univariate sampling bootstrap (HI) and the observed-imposed univariate sampling bootstrap (OI). The authors simulated correlated populations with various combinations of normal and skewed variates. With alpha set=.