# Explanation of errata

An erratum tells you where to find an error and what correction should be applied. Details are provided below using an example from Generalized Linear Models and Extensions.

The erratum below shows that for the first printing of Generalized Linear Models and Extensions, a space needs to be removed from the equation logit (z) = ... to produce logit(z) = .... You can find the error on page 107, equations 10.6 and 10.7.

 (1) Chapter 10, p. 107, section 10.4, equation numbers 10.6 and 10.7
 logit (z) = ... logit(z) = ... = -logit (y) = -logit(y)

An erratum has two parts.

1. The first line of the entry tells you where to find the error.
• The first item of the first line (in parentheses) tells the printing number(s) for which this erratum applies. (Click here to learn how to determine the printing number of a book.) If your book is a later printing number than that mentioned, you can ignore the entry. The word “all” will appear instead of a number if the erratum applies to all printings of the book.
• The second item on the first line tells you which chapter the erratum applies to. Above, the error is in chapter 10 of Generalized Linear Models and Extensions.
• The third item on the first line gives the page number for the correction (p. 107 in the example above).
• The first line of an erratum entry ends with more information to indicate where the error can be found. The example above directs you to section 10.4, equation numbers 10.6 and 10.7.
2. The second part of an erratum entry is below the first line of the entry and tells you what correction should be made. This information can appear in several formats depending on the error.
• The most common form of an erratum is for changes. These are shown with the error in the left box and the correction in the right box. The example above follows this format, and you can see that an extra space was put between logit and the opening parenthesis. Sometimes a clarifying note will precede the listing of the change.
• If something is to be deleted, a note to that effect will be shown.
• If something is to be added, a note will indicate where to make the addition, which will be shown in a box.
• If a correction is complicated or large, a note will provide a link to the correction.
• If there are many corrections in the same section and on the same page, the corrections will appear one after another within the same erratum entry.