Lost Opportunities: Why We Need a Variety of Statistical Languages

To the worker who only has a hammer, we are told, everything looks like a nail. Solutions to applied statistical problems are framed by the limitations imposed by statistical computing packages and languages. For better or worse, we can do what the packages do; we cannot do what the packages won't do. Statistical languages like R have basic tools that allow the analyst to design new hammers, but even in R we cannot build an arbitrary hammer, only ones within the limits imposed by the R language. XLISP-STAT imposes different limitations, so we can produce different hammers. In this article, I look at some of the tools in XLISP-STAT that allow the user to think about graphics in ways that cannot be easily replicated in other statistical languages. The interactive graphical methods available in XLISP-STAT lead to very different methodology than would be developed without the tools that XLISP-STAT provides. The general approach to graphics and indeed to data analysis in general is quite different in a package like Arc that is built on top of XLISP-STAT, than it is in other statistical packages. We discuss why that might be true, and why this depends on design options created by XLISP-STAT

A Statistic for Allocating Cp to Individual Cases

1 online resource (PDF, 21 pages

A New Method for the Statistical Analysis of Dual Labeled Isotope Polypeptides Separated by Gel Electrophoresis

1 online resource (PDF, 20 pages

Some Principles for Regression Diagnostics and Influence Analysis: Comments on "Developments in Linear Regression Methodology: 1959-1982"

1 online resource (PDF, 15 pages

Two-Way Order Statistics

1 online resource (PDF, 19 pages

A Linear Model Approach to Backcalculation of Fish Length

1 online resource (PDF, 26 pages

Use of cranial characters in taxonomy of the Minnesota wolf (\u3ci\u3eCanis\u3c/i\u3e sp.)

Minnesota wolves (Canis sp.) sometimes are reported to have affinity to a small, narrow-skulled eastern form (Canis lupus lycaon Schreber, 1775) and sometimes to a larger, broader western form (Canis lupus nubilus Say, 1823). We found that pre-1950 Minnesota wolf skulls were similar in size to those of wolves from southeastern Ontario and smaller than those of western wolves. However, Minnesota wolf skulls during 1970–1976 showed a shift to the larger, western form. Although Minnesota skull measurements after 1976 were unavailable, rostral ratios from 1969 through 1999 were consistent with hybridization between the smaller eastern wolf and the western form. Our findings help resolve the different taxonomic interpretations of Minnesota skull morphology and are consistent with molecular evidence of recent hybridization or intergradation of the two forms of wolves in Minnesota. Together these data indicate that eastern- and western-type wolves historically mixed and hybridized in Minnesota and continue to do so. Our findings are relevant to a recent government proposal to delist wolves from the endangered species list in Minnesota and surrounding states. On associe les loups (Canis sp.) du Minnesota quelquefois avec une forme de l’est de petite taille et à crâne étroit (Canis lupus lycaon Schreber, 1775) et d’autres fois à une forme de l’ouest (Canis lupus nubilus Say, 1823) plus grande et à crâne plus large. Nous observons que les crânes de loups du Minnesota récoltés avant 1950 sont de taille semblable à ceux de loups du sud-est de l’Ontario et plus petits que ceux des loups de l’ouest. Cependant, les crânes de loups du Minnesota durant la période de 1970–1976 montrent un déplacement de taille vers la forme plus grande de l’ouest. Bien qu’aucune mesure de crânes du Minnesota ne soit disponible après 1976, les rapports des rostres de 1969 jusqu’à la fin de 1999 sont compatibles avec une hybridation entre le loup plus petit de l’est et la forme de l’ouest. Nos données aident à résoudre les différences d’interprétation taxonomique de la morphologie des crânes du Minnesota et concordent avec les preuves moléculaires d’une hybridation récente ou d’une intégration des deux formes de loups du Minnesota. Conjointement, ces données indiquent que les loups des types est et ouest se sont mêlés et hybridés dans le passé au Minnesota et continuent de le faire. Nos résultats sont pertinents compte tenu d’une proposition gouvernementale récente de retirer les loups de la liste des espèces en péril au Minnesota et dans les états adjacents

Log-Linear Models for Dyad Formations

1 online resource (PDF, 26 pages

Visualizing Fit and Lack of Fit in Complex Regression Models with Predictor Effect Plots and Partial Residuals

Predictor effect displays, introduced in this article, visualize the response surface of complex regression models by averaging and conditioning, producing a sequence of 2D line graphs, one graph or set of graphs for each predictor in the regression problem. Partial residual plots visualize lack of fit, traditionally in relatively simple additive regression models. We combine partial residuals with effect displays to visualize both fit and lack of fit simultaneously in complex regression models, plotting residuals from a model around 2D slices of the fitted response surface. Employing fundamental results on partial residual plots along with examples for both real and contrived data, we discuss and illustrate both the strengths and limitations of the resulting graphs. The methods described in this paper are implemented in the effects package for R