[4th corner Icon] Le Quatrième Coin/The 4th-Corner

Pierre Legendre
May 1996
Département de sciences biologiques
Université de Montréal
The 4th-corner method, which was presented at the NT-95 meeting, offers a way of analyzing relationships between the supplementary variables associated with the rows and columns of a binary (presence-absence) data table (Legendre et al., 1997). The problem which motivated the development of the method is the following: How does one relate the biological and behavioral characteristics of animals (matrix B) to habitat characteristics of the locations at which they are found (matrix C), given the distribution of animals across sampling sites (matrix A)? Statistical parameters in matrix D are estimated by the following matrix operation: D = C A' B. They are tested for significance using a permutation procedure. Random permutations of matrix A can be obtained under four different permutational models. Documents available for distribution include: The program documentation files have been designed to be printed in either US Letter or A4 formats. Reference:
Legendre, P., R. Galzin & M. L. Harmelin-Vivien. 1997. Relating behavior to habitat: solutions to the fourth-corner problem. Ecology 78: 547-562.

Last updated on Saturday, March 30, 2013 by Philippe Casgrain
Created on Friday, October 03, 1997