**Errata for Analysis of Ecological Communities**

**2nd Printing (August 2006); check back of title page to determine printing.**

Please don't hesitate to contribute to the list!

p. 56, The Sorensen distance between Plot 4 and Plot 2 should be 81.8, not 83.3

p. 117, Replace "A is the original data matrix" with "B is the centered and standardized data matrix"

p. 117, Equation for Score1, replace each a with b.

p. 197, the calculation of the factorial sums of squares was incorrectly abbreviated from Anderson's (2001)original (correct) treatment. The text on p. 197 can be corrected as follows:

SSw(A) = within-group sum of squares for A

SSw(B) = within-group sum of squares for B

SSA = SST - SSw(A)

SSB = SST - SSw(B)

The remaining equations (SSR, SSAB) are correct

p. 204, first line, the sentence beginning "Either the highest average p-value..." should read "Either the lowest average p-value..."

**1st Printing (2002)**

p. 56, The Sorensen distance between Plot 4 and Plot 2 should be 81.8, not 83.3

p. 108, first equation should be alpha = arccos(r_x * |r_x| / h). The h was omitted.

p. 117 middle of left column, X = A Y should be X = B Y (assuming the data were standardized). B is the standardized data matrix.

p. 121, first complete paragraph. Negative eigenvalues are not always obtained with principal coordinates analysis but they should be expected if non-Euclidean distance measures are used. Change first sentence of this paragraph from "At least one of the resulting eigenvalues is always negative" to "One or more of the resulting eigenvalues can be negative".

p. 136, Under "What to report" add the following: "Final stress for the best run."

p. 136, the last line in the second column is missing. Please insert: "forget to describe the gradients in species" at the bottom of that column.

p. 173, 4th paragraph, line 3, exponent should be -13, not -10.

p. 197. See correction listed above for 2nd printing.

Appendix 1. p. 259, upper right corner: The third term in determinant should be: a13a21a32 not

a13a23a32

p. i. (inside front cover): Duke University is in Durham, not Chapel Hill. Dean Urban's information on the back cover is correct.