Explore the vast range of titles available.

In statistical modeling, we strive to specify models that resemble data collected in studies or observed from processes. Consequently, distributional specification and parameter estimation are central to parametric models. Graphical procedures, such as the quantile-quantile (Q-Q) plot, are arguably the most widely used method of distributional assessment, though critics find their interpretation to be overly subjective. Formal goodness of fit tests are available and are quite powerful, but only indicate whether there is a lack of fit, not why there is lack of fit. In this article, we explore the use of the lineup protocol to inject rigor into graphical distributional assessment and compare its power to that of formal distributional tests. We find that lineup tests are considerably more powerful than traditional tests of normality. A further investigation into the design of Q-Q plots shows that de-trended Q-Q plots are more powerful than the standard approach as long as the plot preserves distances in x and y to be the same. While we focus on diagnosing nonnormality, our approach is general and can be directly extended to the assessment of other distributions.

The complexity of linear mixed-effects (LME) models means that traditional diagnostics are rendered less effective. This is due to a breakdown of asymptotic results, boundary issues, and visible patterns in residual plots that are introduced by the model fitting process. Some of these issues are well known and adjustments have been proposed. Working with LME models typically requires that the analyst keeps track of all the special circumstances that may arise. In this article, we illustrate a simpler but generally applicable approach to diagnosing LME models. We explain how to use new visual inference methods for these purposes. The approach provides a unified framework for diagnosing LME fits and for model selection. We illustrate the use of this approach on several commonly available datasets. A large-scale Amazon Turk study was used to validate the methods. R code is provided for the analyses. Supplementary materials for this article are available online.

Graphics are very effective for communicating numerical information quickly and efficiently, but many of the design choices we make are based on subjective measures, such as personal taste or conventions of the discipline rather than objective criteria. We briefly introduce perceptual principles such as preattentive features and gestalt heuristics, and then discuss the design and results of a factorial experiment examining the effect of plot aesthetics such as color and trend lines on participants' assessment of ambiguous data displays. The quantitative and qualitative experimental results strongly suggest that plot aesthetics have a significant impact on the perception of important features in data displays. Supplementary materials for this article are available online.

In the classroom, we traditionally visualize inferential concepts using static graphics or interactive apps. For example, there is a long history of using apps to visualize sampling distributions. The lineup protocol for visual inference is a recent development in statistical graphics that has created an opportunity to build student understanding. Lineups are created by embedding plots of observed data into a field of null (noise) plots. This arrangement facilitates comparison and helps build student intuition about the difference between signal and noise. Lineups can be used to visualize randomization/permutation tests, diagnose models, and even conduct valid inference when distributional assumptions break down. This article provides an overview of how the lineup protocol for visual inference can be used to build understanding of key statistical topics throughout the statistics curriculum. Supplementary materials for this article are available online.

See generally John J. Ensminger, Tadeusz Jezierski & Michael McCulloch, Scent Identification in Criminal Investigations and Prosecutions: New Protocol Designs Improve Forensic Reliability (Oct. 19, 2010) (unpublished manuscript), available at http://tinyurl.com/cp7dudr (summarizing cases in the thus far definitive analysis in the twenty-first century of the case law and science of dog scent lineups).) [...]in this brief piece I have only touched on some of the many complex issues that can arise with dog scent lineups. [...]important is it that counsel be properly trained in the science to be effective crossexaminers and overall advocates that the National Association of Criminal Defense Lawyers, pursuant to a United States Department of Justice grant, presented a panel in 2009 specifically on dog scent lineups-a panel on which I and Dr. Larry Myers were the principal speakers.

Vancouver senior says she's disgusted with city's lack of snow removal VANCOUVER _ Residents and officials are struggling to deal with that most Canadian of inconveniences _ snow _ following near-record snowfall in this West Coast city in recent weeks. Job losses expected to mount, but silver lining shows in economy's black cloud OTTAWA _ Just as the Canadian and United States economies appear at their weakest in years, many private sector economists say they spot the beginnings of a silver lining peaking through the gloom.