# Introduction to Information Retrieval: Errata

This page lists errata for Introduction to Information Retrieval by Christopher D. Manning, Prabhakar Raghavan and Hinrich Schütze.

Entries are of the form: p. x, line y, change "A" to "B"
Page numbers are with respect to the printed book = irbookprint.pdf.
Line counts ignore figures, equations and other displayed material.
Negative line counts are from the bottom of the page.

## CORRECTIONS MADE IN THE 2ND PRINTING OF IIR

FRONT MATTER

p.xix Insert in list of Acknowledgments in the paragraph beginning "We are very grateful ..."
Björn Andrist
Miklós Erdélyi
Marek Kowalkiewicz
Karthik Raghunathan

p.xx Insert in list of Acknowledgments in the paragraph beginning "Many people gave us ..."
Valentin I. Spitkovsky

CHAPTER 3

p.48, end of 3rd paragraph "A walk down the reverse B-tree then enumerates all terms $R$ in the vocabulary with
a given prefix." Should be "A walk down the reverse B-tree then enumerates
all terms $R$ in the vocabulary with a given postfix."
p.48, towards end of 4th paragraph Immediately before the sentence "Finally, we use the standard ...",
insert the following new sentence: We scan and filter out any terms that match the prefix as well as
the suffix because these two strings overlap (for instance, the query
\query{ba*ba} would result in the term \term{ba} being in $W\cap R$; this
would be filtered out).  FIXING THIS ALSO CHANGED p.49 OF PRINTED BOOK.

p.55, line 2: "given a set ${\cal S}$ of strings" should be "given a set $V$ of strings"

CHAPTER 6

pp.100-123: Throughout Chapter 6, change all occurrences of "non-relevant" to "nonrelevant".

p.103, line 5: "maps the presence of query terms in a zone to ${0,1}$."
should be "maps the presence of query terms in a zone to $\{0,1\}$." i.e.,
the curly braces should be made to print.

p.109, line 2: "gives an example of idfs" should be "gives an example of idf's"

p.112: Figure 6.12: "and" before "Pride and Prejudice" should not be italicized

p.114, Example 6.4 final sentence "Invoking (6.9) ..." should be "Invoking (6.12) ..."

p.115, line 8: change "the the" to "the" before "array Scores"
p.115, lines 9-10: "When the scores are finally computed in Step 11, all that remains
in Step 12 is to pick off the $K$ documents with the highest scores." should
be "When the scores are finally computed in Step 9, all that remains in Step
10 is to pick off the $K$ documents with the highest scores."
p.115, line 17: "it seems appear necessary to store" - delete "appear"

CHAPTER 7

p.125, Figure 7.1, line 5: \mbox{calculate }\mbox{w}_{t,q}\mbox{ and fetch postings list for }t\\
Should be \mbox{ fetch postings list for }t\\
p.125, line 5: "with line 8 altered since we take" should be "with line 7 altered since we take"

p.132, line 13: "A common solution to this issue is the user of" should be "A
common solution to this issue is the use of"

p.134 "Rank them by vector space ..." should be "Rank the results by vector space ..."

CHAPTER 10

p.191, figure 10.10, lower the starting point of the three arrows
(the starting point should be on the lower line of
the box, not in the box)
p.191, figure 10.10, lower the end point of the second arrow
(its end position should be at
about 50% of the second box)
p. 191, figure 10.10, lower the end point of the third arrow
(its end position should be at
about 50% of the third box)

CHAPTER 11

p.208, line 10, change "the the" to "the"

CHAPTER 13

p.244, line 5, change "Bernoulli NB models" to "Bernoulli NB model models"

CHAPTER 14

p.273, line 3, change "Theta(|D|V|)" to "Theta(|D||V|)"

p.280, figure 14.10, continue the non-straight solid line
all the way to the left bounding line (i.e., to the vertical line at
coordinate 0)

CHAPTER 16

p.324, caption of figure 16.2, line 3, change "Cluster" (in italics) to "cluster" (in roman)

p.337, figure 16.8, the figure should depict 9 connected little circles, but
it only shows 8. In other words, add a little circle at the end of the last
line above 10

p.338, line 19, change "2MK" (roman) to "2MK" (math mode = italics)

CHAPTER 17

p.357, line 9, change "implimentations" to "implementations"

CHAPTER 20

p.415, line 9, exercise 20.3: change "number back queues" to "number of back queues"

CHAPTER 21

p.427, line 6, change "the its states" to "its states"

p.437, line 9, "inclusion of pages points to" should be
"inclusion of pages pointing to"

INDEX

p.471, change page list for "Document-partitioned index" to "68, 70, 415"
p.471, delete entry for "Document!partitioning"

p.473, change page list for "Indexes!document-partitioned" to  "68, 70, 415"
p.473, change page list for "Indexes!term-partitioned" to  "68, 70, 415"

p.480, change page list for "Term-partitioned index" to "68, 70, 415"
p.480, delete entry for "Terms!partitioning"


## CORRECTIONS MADE IN THE 3RD PRINTING OF IIR

FRONT MATTER

p.xix-xx: Insert in list of Acknowledgments in the paragraph beginning
"We are very grateful ..."
Marek Kowalkiewicz
Juha Makkonen
Dell Zhang

CHAPTER 2

p. 36, line -4, insert comma after "For example"

CHAPTER 3

p.54: Figure 3.5: line 8 is missing a space before the closing "fi."

p.60, line 2: "candidate mismatches" should be "candidate matches"

CHAPTER 4

p.64, Table 4.2, last line: add the symbol T in math mode
($T$) in the first
column. The last line should then read:
T        tokens            100,000,000

p.66, line -17: Insert space between "SPIMI." and
"SPIMI". (The first SPIMI should be set as "SPIMI\@.")

p.66, line -12: The hyphen in "term-docID" needs to be
longer. (That is, set this as "term--docID" as was done for
other hyphenated expressions.)

p.68, line -10: Replace "shouldn't" with "should not"

p.72, footnote: Replace "ch. 19" with "Chapter 19"

CHAPTER 5

p.81, Figure 5.1
p.83, Figure 5.2
"least squares fit" vs "least-squares fit"
Change the caption of Figure 5.1 on p.81 to include
a hyphen between "least" and "squares"

p.89, Figure 5.8, line 3 of caption: Change "Preprend" to "Prepend"

p.90, section heading of 5.3.2: change "Codes" to "codes"

p.96, line 9: change "Codes" to "codes"

CHAPTER 11

p.204, line 5: Change "the cost of retrieval of a relevant document"
to "the cost of not retrieving a relevant document"

p.204, eqn (11.7), on both sides of comparison, swap order of terms
and join with minus:
C_0\cdot P(R=0|d) - C_1\cdot P(R=1|d) \le C_0\cdot P(R=0|d') -  C_1\cdot
P(R=1|d')

p.209, numbered item 3:  Replace the last two lines of text starting
not observed empirically: as might be expected, $p_t$ is shown to rise
with $\docf_t$.  Based on
his data analysis, a plausible proposal would be to use the estimate
$p_t =\frac{1}{3} + \frac{2}{3}\docf_t/N$.

CHAPTER 13

p.237, line -3: add a prime sign (or apostrophe) after d in
gamma(d). The line should then read: gamma(d')=China, which ...

p.240, line -14: replace "we're" with "we are"

p.240, line -7: replace "occuring" with "occurring"

p.242, line -9: after "Finally," add "assuming that the
length of test documents is bounded,"

p.252, table above footnote: The numbers in two table cells are
reversed.
In upper right corner of the table, replace the number after equals sign
with: 27,652
In lower left corner of the table, replace the number after equals sign
with: 141
Set the two occurrences of poultry and the two occurrences
of export in the same fonts as in the table in Example 13.4
on page 255. That is, set "poultry" in italics and set
"export" in textsf (sans serif).

p.252, footnote, replace Equation (13.17) with Equation (13.18)

p.253, formula below line 1: replace the number after the
approx sign with: 0.0001105 (that is, there should be two
1s, not one 1)

p.255, table above line -6: The numbers in two table cells are reversed.
In upper right corner of table, replace the number after equal sign with
27,652 and
the number after approx sign with 27,694.4.
In left lower corner of table, replace the number after equal sign with
141 and
the number after approx sign with 183.4

p.258, table in Exercise 13.5: Set the four words brazil,
council, producers, and roasted using textsf (the same way
all terms are set, e.g., the terms london, british, britain
in Table 13.7).

p.264, line -14: replace "the two \chi^2 formulas" with "the
two X^2 formulas". Use the same symbol as is
displayed as the first symbol of the two equations that the
exercise refers to (13.18 and 13.19).

CHAPTER 15

p.298, line 11: Change "will be helpful to" to "will be helpful in"

p.314, line -1: Change "Figure ??" to "Table 15.3"

p.315, line -13: Change "Becuase" to "Because"

CHAPTER 16

p.330, line 12: insert "of" after "maximum". The sentence
then should read "reaches its maximum of log N"

p.338, line -2: insert "and covariance is spherical" after
"distributed". The sentence should then read "If the noise
is normally distributed and covariance is spherical, this
procedure will result in clusters of spherical shape."

CHAPTER 17

p.348, Figure 17.1: Align the document title "Backtoschool
spending is up" with the other document titles. Remove the
period from "Ag trade reform." and also align this title with the
other document titles.

p.349, Figure 17.2, line 5: change "collects" to "assembles"

p.352, Figure 17.5: Align the document title "Backtoschool
spending is up" with the other document titles. Remove the
period from "Ag trade reform." and also align this title with the
other document titles.

p.361, line 5: change "over" to "on" (sentence should then
read: by induction on the number of clusters K)

CHAPTER 19:

p.387, first line of Section 19.2: "growth of the web" – replace ‘web’
by ‘Web’

p. 388, lines 10 and 11: “content creation on the web” and “the web
contained truth” - replace ‘web’ by ‘Web’

p. 388 bottom line: "as show in" should be “as shown in”

CHAPTER 20:

p.412, line 12: change "the designers of Mercator recommend of the
order of five attempts" to “Mercator's designers recommend roughly
five attempts”

p.415, line 5 of Section 20.3: "also know as local index" -> “also known
as local index”

p.426, fourth line from the bottom: "such the visit frequency converges”
should be “the visit frequency converges”

p.426, line -3: Insert "a" before "fixed, steady-state quantity".

p.428: Beginning of the page: move the footnote 2 to be at the end of
the sentence after "steady state." (so it's not confused with the math
material).