\documentclass{article}
\usepackage{url}
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\author{Ben Bolker}
\title{Ecological Detective: errata}
\date{\today}
\begin{document}
\maketitle
\newcommand{\Iobs}{I_{\mbox{\small obs}}}
\newcommand{\Ipre}{I_{\mbox{\small pre}}}
\newcommand{\Aest}{A_{\mbox{\small est}}}
\newcommand{\Best}{B_{\mbox{\small est}}}
\newcommand{\Cest}{C_{\mbox{\small est}}}
\newcommand{\impt}{{\color{red}\large\textbf{*}}}
\includegraphics[width=2.64cm,height=0.93cm]{cc-attrib-nc.png}
\begin{minipage}[b]{3in}
{\tiny Licensed under the Creative Commons
attribution-noncommercial license
(\url{http://creativecommons.org/licenses/by-nc/3.0/}).
Please share \& remix noncommercially,
mentioning its origin.}
\end{minipage}
\emph{Last substantive change:} 10 October 2001
These range from fussy typographical details (e.g., whether particular
variables should be italicized) to fairly significant and/or confusing
errors.
Particularly important or confusing errors are marked \impt.
See the
%ED website
ED web site
\url{http://www2.ucsc.edu/people/msmangel/ED.html}
for more details.
Thanks to Marc Mangel and Ray Hilborn for writing a great book that
has relatively few errors, and to Tom Hobbs for pointing out several
of the errors below.
Please contact me at {\tt bolker@mcmaster.ca} if you know of any
other errors in the text, or if you find mistakes in this list.
\begin{itemize}
\item{p. 25 eq. 2.1, model B: uppercase $A$ should be lowercase $a$ for consistency}
\item{p. 28 eq B2.1: first equals sign is spurious}
\item{p. 38 para. 2 l. 2 read ``model'' for ``mode''}
\item{p. 53 second to last displayed equation, LHS should be
$Q(t+\Delta t)$ rather than $Q(t+dt)$}
\item{p. 58 eq. 3.30: first $m_1$ in equation should be italicized}
\item{p. 58 eq. 3.31: last $z$ (second line of equation, squared term)
should be uppercase}
\item{p. 61, ll. 2-3 after (3.41): uppercase $A$ should be lowercase $a$}
\item{pp. 66-68, (3.47-3.48, 3.50) and pseudocodes 3.1,3.3: all $p$ before open
parenthesis [$p($] should be uppercase ``$P($'' [or ``Pr(''
to match earlier notation)}
\item{p. 68, (3.51): $k$ in exponent should be italic}
\item{\impt p. 73, first line of (3.65): sum should run from 1, not $X$}
\item{p. 81, (3.84): $a$ in denominator of last fraction should be italic}
\item{p. 84, (3.91): $s$ and $r$ should be italic}
\item{p. 90, pseudocode 3.4: $\sigma_N$ doesn't need to be specified
(it's a function of $\sigma_W$ and $\sigma_V$).}
\item{\impt p. 103, (4.9) et seq.:
The correct formula for the Pearson $\chi^2$ test
should be in terms of numbers, not frequencies:
\newcommand{\Ntow}{N_{\mbox{\small tow}}}
$$
\chi^2 = \sum_{c=0}^{17} \frac{[ n(c) - p(c) \Ntow]^2}{p(c) \Ntow}
$$
(alternately, one can multiply the entire RHS of the formula given
by $\Ntow$).
Furthermore, the discussion is slightly misleading:
$p(c)$ is rarely zero for most probability models,
the problem is actually with expected counts $< 5$ (see any
elementary statistics book for discussion of the Pearson test;
one heuristic for this rule of thumb is that the Poisson distribution
is reasonably close to Normal for expected means $> 5$).}
\item{\impt p. 111: The parameter $A$ ranges from -1 to 3.}
\item{\impt p. 112, (5.5): in first eq., $\Aest$ should be $A$; in second eq.,
$\Best$ should be $B$; in third eq., $\Cest$ should be $C$}
\item{p. 115, l. -7: replace ``$n$ parameters'' by ``$m'$ parameters''
[ed: arguably, you could just change this sentence to
``More generally, how do we compare models with different
numbers of parameters?''];
just below eqn. 5.11, add ``where $n$ is the number of data points and
$m$ is the number of parameters''
}
\item{p. 126, l. 5 and -8 of main text, p. 129 l. 2:
in each case the denominator of the fraction
should have parentheses around it to be technically correct
(and less confusing); so,
$\mbox{SSQ}^*/N_c-6 \to \mbox{SSQ}^*/(N_c-6)$,
$\mbox{SSQ}^*/N_c-10 \to \mbox{SSQ}^*/(N_c-10)$, and
$\mbox{SSQ (single switch)}/N_c-6 \to \mbox{SSQ (single switch)}/(N_c-6)$.}
\item{p. 137, one line after eq. 7.12: ``negative log-likelihood for
10 of the ten heights'' should be ``negative log-likelihood for
$n$ of the ten heights''}
\item{p. 138, Figure 7.2: x axis label should be ``Mean height (cm)'' (not m)}
\item{p. 154, l. 5 after eq. 7.42 ``ratio of the logarithm'' should be
``logarithm of the ratio''}
\item{\impt p. 156, first paragraph and pseudocode 7.4: the
description of how Poisson variability is added disagrees with
common sense and with Figure 7.7/Table 7.1. The book says:
\begin{quote}
Suppose that the number of individuals observed,
$\Iobs$, is the true number plus an observation uncertainty
$V$ that is Poisson distributed. Thus, $\Iobs=I+V$ will always equal
or exceed the true number because $V \ge 0$.
\end{quote}
In Figure 7.7/Table 1.1, $\Iobs$ (black dots in figure; third column
in table) is \emph{not} $\ge$ the true number $I$ (dashed line in
figure; second column in table). Furthermore, following this
interpretation makes it hard to figure out what the mean of the
Poisson distributed term should be.
What is probably meant is that the
observed value, $I_{\mbox{obs}}$, is drawn from a Poisson distribution
with a mean of $I$.
Following this interpretation:
\begin{itemize}
\item{change ``plus an observation uncertainty $V$ that is Poisson
distributed'' on p. 156, ll. 5 ff. to ``with an observation
uncertainty that is Poisson distributed'';}
\item{delete the next sentence, beginning ``Thus, \ldots'';}
\item{step 4 in pseudocode 7.4 should
read: ``4. Calculate the actual observation by drawing a random number
from a Poisson distribution whose mean is equal to the result from
step 3.''.}
\end{itemize}
The negative log-likelihood in Pseudocode 7.5, step 3c is
$\mbox{Pr}(I=\Iobs|I \sim \mbox{Pois}(\lambda=\Ipre))$---the
probability of drawing a sample $\Iobs$
from a Poisson distribution with mean $\Ipre$.
[ed: I haven't checked this error with the authors, there
is some possibility that I'm just confused---but I don't think so]
}
\item{\impt p. 159, eqn 7.45: The definition of AIC should be
$A_i = 2 L(Y|M_i^*) + 2 p_i$
where $L(Y|M_i^*)$ is the minimum value of the negative log-likelihood,
evaluated at the best choice of parameters for
model $M_i$}
\item{p. 202, l. 21: ``Haddad'' is misspelled}
\item{\impt p. 217, l. -8: $r+1$ should be $a+1$}
\item{p. 277, l. -15: ``systems'' should be singular}
\item{p. 277, l. -13: S-PLUS\textsuperscript\textregistered\ (not S+)
is a registered trademark of Insightful (this is picayune, but all the other
commercial packages are listed with \texttrademark)
[ed.: R
(\url{http://www.r-project.org}}
is a public-domain clone that's just as good]
\end{itemize}
\end{document}