Multivariate
Statistics for Wildlife and Ecology Research
(NRC
631)
Lab
Projects
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The Multivariate Statistics for Wildlife and Ecology Research (NRC 631)
Lab includes several major projects corresponding to the major statistical
techniques covered in this course (see Schedule).
Each of these projects are briefly described below and include links to
detailed descriptions of each assignment and downloads of all required
data and scripts. All documents in pdf format require Adobe
Acrobat Reader to view.
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| Mvstats Pseudo-R-Library |
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Mvstats.R is suite of R functions written to facilitate the analysis
of multivariate data sets in this course. This suite of functions is written
in the spirit of growing up to become a fully fledged library in R, but
for now it is just a humble set of functions that must be sourced before
using. This library will be updated constantly, possibly for each lab,
so it will need to be downloaded and sourced each lab. In addition, the
corresponding help file contains all the supporting documentation for the
functions and is written in the spirit of the standard R function help
pages (for better or worse).
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| Lab 1: Introduction to R |
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The first lab will introduce students to the R programming and statistical
computing environment. Students will gain only a preliminary working understanding
of how to work in R. The purpose of this lab is to give students enough
understanding and working skills to successfully complete the remaining
lab projects, not teach students to become R experts.
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| Lab 2: Data screening and
adjustment |
| This lab is designed to give students hands-on experience
using R to prepare, screen and potentially adjust a multivariate data set
in preparation for analysis. Students will not be expected to evaluate the
data set from every possible angle and using every possible analytical procedure
available. Rather, the purpose of this project is to give students some
basic experience in screening and adjusting data using R.
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| Project 1: Unconstrained
ordination |
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This project is designed to give students hands-on experience using a
variety of unconstrained ordination techniques, including Principal Components
Analysis (PCA), Correspondence Analysis (CA), Detrended Correspondence
Analysis (DCA), Principal Coordinates Analysis (PCO) and Nonmetric Multidimensional
Scaling (NMDS) to analyze a multivariate data set. As such, students will
not be expected to analyze the data set from every possible angle and using
every possible analytical procedure available. Rather, the purpose of this
project is to give students some basic experience in how unconstrained
ordination techniques work and how R an be used to do the analysis.
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| Project 2: Cluster analysis |
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This project is designed to give students hands-on experience using Cluster
Analysis (CA) to analyze a multivariate data set. As such, students will
not be expected to analyze the data set from every possible angle and using
every possible analytical procedure discussed in class. Rather, the purpose
of this project is to give students some basic experience in how CA works
and how R can be used to do the analysis.
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| Project 3: Discrimination
among groups |
| This project is designed to give students hands-on experience
using Discriminant Analysis (DA), Classification and Regression Trees (CART)
and Multi-response Permutation Procedures (MRPP) to analyze one of several
available multivariate data sets. The purpose of this project is to expose
students to DA, CART and MRPP procedures for exploration, description and
prediction of grouped data. As such, students will not be expected to analyze
the data set from every possible angle and using every analytical procedure
available. Rather, the purpose of this project is to give students some
basic experience in how various discrimination techniques work and how R
can be used to do the analysis.
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| Project 4: Constrained Ordination (CCA and
RDA) |
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This project is designed to give students hands-on experience using constrained
ordination (CCA/RDA/CAP) to analyze a multivariate data sets. Specifically,
students will learn how to conduct Canonical Correspondence Analysis (CCA)
or Redundancy Analysis (RDA) using R. Constrained Analysis of Principal
Coordinates (CAP) is similar but will not be done here. Students will learn
how to screen and adjust the data set (e.g., select species and explanatory
variables) and conduct the constrained ordination. In addition, students
will learn how to evaluate the performance of the model and interpret the
relationships among species, samples and environmental variables. Finally,
students will learn how to do a simple 2- or 3-part variance decomposition.
Students will not be expected to analyze the data set from every possible
angle and using every possible analytical procedure available. Rather,
the purpose of this project is to give students some basic experience in
how CCA/RDA work and how R can be used to do the analysis.
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