Pseudoreplication is defined. as the use of inferential statistics to test for treatment effects with data from experiments where either treatments are not replicated (though samples may be) or replicates are not statistically independent. In ANOVA terminology, it is the testing for treatment effects with an error term inappropriate to the hypothesis being considered. Scrutiny of 176 experi- mental studies published between 1960 and the present revealed that pseudoreplication occurred in 27% of them, or 48% of all such studies that applied inferential statistics. The incidence of pseudo- replication is especially high in studies of marine benthos and small mammals. The critical features of controlled experimentation are reviewed. Nondemonic intrusion is defined as the impingement of chance events on an experiment in progress. As a safeguard against both it and preexisting gradients, interspersion of treatments is argued to be an obligatory feature of good design. Especially in small experiments, adequate interspersion can sometimes be assured only by dispensing with strict random- ization procedures. Comprehension of this conflict between interspersion and randomization is aided by distinguishing pre-layout (or conventional) and layout-specifit alpha (probability of type I error). Suggestions are offered to statisticians and editors of ecological j oumals as to how ecologists' under- standing of experimental design and statistics might be improved.

/pdf/pseudoreplication-and-the-design-of-ecological-field-44o8kzdaoi.pdf

Pseudoreplication and the Design of Ecological Field Experiments

https://files.eric.ed.gov/fulltext/ED045723.pdf

Comparison of Bayesian and Regression Approaches to the Study of Information Processing in Judgment.

Maize silage is a significant energy source for animal production operations, and the efficiency of the conversion of forage into animal mass is an important consideration when selecting cultivars for use as feed. Fiber and lignin are negatively correlated with digestibility of feed, so the development of forage with reduced levels of these cell-wall components (CWCs) is desirable. While variability for fiber and lignin is present in maize germplasm, traditional selection has focused on the yield of the ear rather than the forage quality of the whole plant, and little information is available concerning the genetics of fiber and lignin. The objectives of this study were to map quantitative trait loci (QTLs) for fiber and lignin in the maize stalk and compare them with QTLs from other populations. Stalk samples were harvested from 191 recombinant inbred lines (RILs) of B73 (an inbred line with low-to-intermediate levels of CWCs) x De811 (an inbred line with high levels of CWCs) at two locations in 1998 and one in 1999 and assayed for neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL). The QTLs were detected on nine chromosomes, mostly clustered in concordance with the high genetic correlations between NDF and ADF. Adjustment of NDF for ADF and ADF for ADL revealed that most of the variability for CWCs in this population is in ADF. Many of the QTLs detected in this study have also been detected in other populations, and several are linked to candidate genes for cellulose or starch biosynthesis. The genetic information obtained in this study should be useful to breeding efforts aimed at improving the quality of maize silage.

Quantitative trait loci for cell-wall components in recombinant inbred lines of maize (Zea mays L.) I: stalk tissue.

Social perceivers process selected aspects of the stimulus array presented by another person. This article argues that such selectivity is based on the informativeness of person attributes. Properties of the attribute itself—its evaluative extremity (distance from the scale midpoint) and its evaluative valence (positive or negative)—can make it informative. Informative attributes attract selective attention at input and also carry extra weight in the final impression. In the present research, negativity and extremity were manipulated across two separate behavioral dimensions, sociability and civic activism, and over 16 stimulus persons. Perceivers saw two prescaled behavior photographs for each stimulus person and controlled a slide changer switch—this provided a measure of attention as looking time. Perceivers also rated each stimulus person's likability, providing a measure of relative weight for each slide. Weights were derived from Anderson's information integration model. Perceivers preferentially weighted behaviors that were extreme or negative, and the behavioral measure of attention (looking time) replicated the predicted pattern. The results are discussed in light of controversies over the rationality of social information processing.

Attention and weight in person perception: The impact of negative and extreme behavior.

https://pubag.nal.usda.gov/download/21951/PDF

Gertrude M. Cox

Papers

Experimental designs, 2nd ed.

Experimental Designs, Second Edition.

Disproportionate subclass numbers in tables of multiple classification

Calcium, phosphorus and nitrogen metabolism of young college women.

Enumeration and Construction of Balanced Incomplete Block Configurations