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Transcript of Aprotocolfordataexploraonto · PDF fileNeil J. Walker Anatoly A. Saveliev Graham M. Smith ed...
![Page 1: Aprotocolfordataexploraonto · PDF fileNeil J. Walker Anatoly A. Saveliev Graham M. Smith ed Effects Models and Extensions in Ecology with R Springer . 3 Formulate bio ogical hypothesis](https://reader031.fdocuments.net/reader031/viewer/2022022422/5a8f65437f8b9a78648d98d3/html5/thumbnails/1.jpg)
A protocol for data explora.on to avoid common sta.s.cal problems
Zuur et al (2010) Methods in Ecology and Evolu.on
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Zuur et al 2009 (Mixed Effects Models and Extensions in Ecology with R)
• Appendix A – A.1 The data – A.2 Data Explora.on
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Protocol for data explora.on
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Step 1: Are there outliers in Y and X?
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Step 2: Do we have homogeneity of variance?
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Step 3: Are the data normally distributed?
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Step 4: Are there lots of zeros in the data?
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Step 5: Is there collinearity among the covariates?
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Step 6: What are the rela.onships between Y and X variables?
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Step 7: Should we consider interac.ons?
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Step 8: Are observa.ons of the response variable independent?
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What about the code?
• All the code needed to make all the figures that are presented here is part of the supplementary material of the paper!
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The next step: Model selec.on
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