<s>
Google	B-Library
Scholar	I-Library
is	O
a	O
freely	O
accessible	O
web	B-Application
search	I-Application
engine	I-Application
that	O
indexes	O
the	O
full	O
text	O
or	O
metadata	O
of	O
scholarly	O
literature	O
across	O
an	O
array	O
of	O
publishing	O
formats	O
and	O
disciplines	O
.	O
</s>
<s>
Released	O
in	O
beta	O
in	O
November	O
2004	O
,	O
the	B-Application
Google	I-Application
Scholar	O
index	O
includes	O
peer-reviewed	O
online	O
academic	O
journals	O
and	O
books	O
,	O
conference	O
papers	O
,	O
theses	O
and	O
dissertations	O
,	O
preprints	O
,	O
abstracts	O
,	O
technical	O
reports	O
,	O
and	O
other	O
scholarly	O
literature	O
,	O
including	O
court	O
opinions	O
and	O
patents	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
uses	O
a	O
web	O
crawler	O
,	O
or	O
web	O
robot	O
,	O
to	O
identify	O
files	O
for	O
inclusion	O
in	O
the	O
search	B-Application
results	I-Application
.	O
</s>
<s>
For	O
content	O
to	O
be	O
indexed	O
in	O
Google	B-Library
Scholar	I-Library
,	O
it	O
must	O
meet	O
certain	O
specified	O
criteria	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
has	O
been	O
criticized	O
for	O
not	O
vetting	O
journals	O
and	O
for	O
including	O
predatory	O
journals	O
in	O
its	O
index	O
.	O
</s>
<s>
The	O
University	O
of	O
Michigan	O
Library	O
and	O
other	O
libraries	O
whose	O
collections	O
Google	B-Application
scanned	O
for	O
Google	B-Application
Books	I-Application
and	O
Google	B-Library
Scholar	I-Library
retained	O
copies	O
of	O
the	O
scans	O
and	O
have	O
used	O
them	O
to	O
create	O
the	O
HathiTrust	O
Digital	O
Library	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
arose	O
out	O
of	O
a	O
discussion	O
between	O
Alex	O
Verstak	O
and	O
Anurag	O
Acharya	O
,	O
both	O
of	O
whom	O
were	O
then	O
working	O
on	O
building	O
Google	B-Application
's	I-Application
main	O
web	O
index	O
.	O
</s>
<s>
This	O
goal	O
is	O
reflected	O
in	O
the	B-Application
Google	I-Application
Scholar	O
's	O
advertising	O
slogan	O
"	O
Stand	O
on	O
the	O
shoulders	O
of	O
giants	O
"	O
,	O
which	O
was	O
taken	O
from	O
an	O
idea	O
attributed	O
to	O
Bernard	O
of	O
Chartres	O
,	O
quoted	O
by	O
Isaac	O
Newton	O
,	O
and	O
is	O
a	O
nod	O
to	O
the	O
scholars	O
who	O
have	O
contributed	O
to	O
their	O
fields	O
over	O
the	O
centuries	O
,	O
providing	O
the	O
foundation	O
for	O
new	O
intellectual	O
achievements	O
.	O
</s>
<s>
One	O
of	O
the	O
original	O
sources	O
for	O
the	O
texts	O
in	O
Google	B-Library
Scholar	I-Library
is	O
the	O
University	O
of	O
Michigan	O
's	O
print	O
collection	O
.	O
</s>
<s>
In	O
2006	O
,	O
a	O
citation	O
importing	O
feature	O
was	O
implemented	O
supporting	O
bibliography	B-Application
managers	I-Application
,	O
such	O
as	O
RefWorks	B-Library
,	O
RefMan	B-Application
,	O
EndNote	B-Library
,	O
and	O
BibTeX	B-Language
.	O
</s>
<s>
In	O
2007	O
,	O
Acharya	O
announced	O
that	O
Google	B-Library
Scholar	I-Library
had	O
started	O
a	O
program	O
to	O
digitize	O
and	O
host	O
journal	O
articles	O
in	O
agreement	O
with	O
their	O
publishers	O
,	O
an	O
effort	O
separate	O
from	O
Google	B-Application
Books	I-Application
,	O
whose	O
scans	O
of	O
older	O
journals	O
do	O
not	O
include	O
the	O
metadata	O
required	O
for	O
identifying	O
specific	O
articles	O
in	O
specific	O
issues	O
.	O
</s>
<s>
In	O
2011	O
,	O
Google	B-Application
removed	O
Scholar	O
from	O
the	O
toolbars	O
on	O
its	O
search	O
pages	O
,	O
making	O
it	O
both	O
less	O
easily	O
accessible	O
and	O
less	O
discoverable	O
for	O
users	O
not	O
already	O
aware	O
of	O
its	O
existence	O
.	O
</s>
<s>
Around	O
this	O
period	O
,	O
sites	O
with	O
similar	O
features	O
such	O
as	O
CiteSeer	B-Application
,	O
Scirus	B-Application
,	O
and	O
Microsoft	O
Windows	B-Application
Live	I-Application
Academic	I-Application
search	I-Application
were	O
developed	O
.	O
</s>
<s>
Some	O
of	O
these	O
are	O
now	O
defunct	O
;	O
in	O
2016	O
,	O
Microsoft	O
launched	O
a	O
new	O
competitor	O
,	O
Microsoft	B-Application
Academic	I-Application
.	O
</s>
<s>
A	O
feature	O
introduced	O
in	O
November	O
2013	O
allows	O
logged-in	O
users	O
to	O
save	O
search	B-Application
results	I-Application
into	O
the	O
"	O
Google	B-Library
Scholar	I-Library
library	O
"	O
,	O
a	O
personal	O
collection	O
which	O
the	O
user	O
can	O
search	O
separately	O
and	O
organize	O
by	O
tags	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
allows	O
users	O
to	O
search	O
for	O
digital	O
or	O
physical	O
copies	O
of	O
articles	O
,	O
whether	O
online	O
or	O
in	O
libraries	O
.	O
</s>
<s>
Because	O
many	O
of	O
Google	B-Library
Scholar	I-Library
's	O
search	B-Application
results	I-Application
link	O
to	O
commercial	O
journal	O
articles	O
,	O
most	O
people	O
will	O
be	O
able	O
to	O
access	O
only	O
an	O
abstract	O
and	O
the	O
citation	O
details	O
of	O
an	O
article	O
,	O
and	O
have	O
to	O
pay	O
a	O
fee	O
to	O
access	O
the	O
entire	O
article	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
Google	B-Library
Scholar	I-Library
does	O
n't	O
allow	O
to	O
filter	O
explicitly	O
between	O
toll	O
access	O
and	O
open	O
access	O
resources	O
,	O
a	O
feature	O
offered	O
Unpaywall	O
and	O
the	O
tools	O
which	O
embed	O
its	O
data	O
,	O
such	O
as	O
Web	B-Library
of	I-Library
Science	I-Library
,	O
Scopus	B-Library
and	O
Unpaywall	O
Journals	O
,	O
used	O
by	O
libraries	O
to	O
calculate	O
the	O
real	O
costs	O
and	O
value	O
of	O
their	O
collections	O
.	O
</s>
<s>
Through	O
its	O
"	O
cited	O
by	O
"	O
feature	O
,	O
Google	B-Library
Scholar	I-Library
provides	O
access	O
to	O
abstracts	O
of	O
articles	O
that	O
have	O
cited	O
the	O
article	O
being	O
viewed	O
.	O
</s>
<s>
It	O
is	O
this	O
feature	O
in	O
particular	O
that	O
provides	O
the	O
citation	O
indexing	O
previously	O
only	O
found	O
in	O
CiteSeer	B-Application
,	O
Scopus	B-Library
,	O
and	O
Web	B-Library
of	I-Library
Science	I-Library
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
also	O
provides	O
links	O
so	O
that	O
citations	O
can	O
be	O
either	O
copied	O
in	O
various	O
formats	O
or	O
imported	O
into	O
user-chosen	O
reference	B-Application
managers	I-Application
such	O
as	O
Zotero	B-Application
.	O
</s>
<s>
Individuals	O
,	O
logging	O
on	O
through	O
a	O
Google	B-Application
account	O
with	O
a	O
bona	O
fide	O
address	O
usually	O
linked	O
to	O
an	O
academic	O
institution	O
,	O
can	O
now	O
create	O
their	O
own	O
page	O
giving	O
their	O
fields	O
of	O
interest	O
and	O
citations	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
automatically	O
calculates	O
and	O
displays	O
the	O
individual	O
's	O
total	O
citation	O
count	O
,	O
h-index	O
,	O
and	O
i10-index	O
.	O
</s>
<s>
According	O
to	O
Google	B-Application
,	O
"	O
three-quarters	O
of	O
Scholar	O
search	B-Application
results	I-Application
pages	O
...	O
show	O
links	O
to	O
the	O
authors	O
 '	O
public	O
profiles	O
"	O
as	O
of	O
August	O
2014	O
.	O
</s>
<s>
Through	O
its	O
"	O
Related	O
articles	O
"	O
feature	O
,	O
Google	B-Library
Scholar	I-Library
presents	O
a	O
list	O
of	O
closely	O
related	O
articles	O
,	O
ranked	O
primarily	O
by	O
how	O
similar	O
these	O
articles	O
are	O
to	O
the	O
original	O
result	O
,	O
but	O
also	O
taking	O
into	O
account	O
the	O
relevance	O
of	O
each	O
paper	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
's	O
legal	O
database	O
of	O
US	O
cases	O
is	O
extensive	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
embeds	O
clickable	O
citation	O
links	O
within	O
the	O
case	O
and	O
the	O
How	O
Cited	O
tab	O
allows	O
lawyers	O
to	O
research	O
prior	O
case	O
law	O
and	O
the	O
subsequent	O
citations	O
to	O
the	O
court	O
decision	O
.	O
</s>
<s>
While	O
most	O
academic	B-Library
databases	I-Library
and	I-Library
search	I-Library
engines	I-Library
allow	O
users	O
to	O
select	O
one	O
factor	O
(	O
e.g.	O
</s>
<s>
relevance	O
,	O
citation	O
counts	O
,	O
or	O
publication	O
date	O
)	O
to	O
rank	O
results	O
,	O
Google	B-Library
Scholar	I-Library
ranks	O
results	O
with	O
a	O
combined	O
ranking	O
algorithm	O
in	O
a	O
"	O
way	O
researchers	O
do	O
,	O
weighing	O
the	O
full	O
text	O
of	O
each	O
article	O
,	O
the	O
author	O
,	O
the	O
publication	O
in	O
which	O
the	O
article	O
appears	O
,	O
and	O
how	O
often	O
the	O
piece	O
has	O
been	O
cited	O
in	O
other	O
scholarly	O
literature	O
"	O
.	O
</s>
<s>
Research	O
has	O
shown	O
that	O
Google	B-Library
Scholar	I-Library
puts	O
high	O
weight	O
especially	O
on	O
citation	O
counts	O
,	O
as	O
well	O
as	O
words	O
included	O
in	O
a	O
document	O
's	O
title	O
.	O
</s>
<s>
In	O
searches	O
by	O
author	O
or	O
year	O
,	O
the	O
first	O
search	B-Application
results	I-Application
are	O
often	O
highly	O
cited	O
articles	O
,	O
as	O
the	O
number	O
of	O
citations	O
is	O
highly	O
determinant	O
,	O
whereas	O
in	O
keyword	O
searches	O
the	O
number	O
of	O
citations	O
is	O
probably	O
the	O
factor	O
with	O
the	O
most	O
weight	O
,	O
but	O
other	O
factors	O
also	O
participate	O
.	O
</s>
<s>
Some	O
searchers	O
found	O
Google	B-Library
Scholar	I-Library
to	O
be	O
of	O
comparable	O
quality	O
and	O
utility	O
to	O
subscription-based	O
databases	O
when	O
looking	O
at	O
citations	O
of	O
articles	O
in	O
some	O
specific	O
journals	O
.	O
</s>
<s>
The	O
reviews	O
recognize	O
that	O
its	O
"	O
cited	O
by	O
"	O
feature	O
in	O
particular	O
poses	O
serious	O
competition	O
to	O
Scopus	B-Library
and	O
Web	B-Library
of	I-Library
Science	I-Library
.	O
</s>
<s>
A	O
study	O
looking	O
at	O
the	O
biomedical	O
field	O
found	O
citation	O
information	O
in	O
Google	B-Library
Scholar	I-Library
to	O
be	O
"	O
sometimes	O
inadequate	O
,	O
and	O
less	O
often	O
updated	O
"	O
.	O
</s>
<s>
The	O
coverage	O
of	O
Google	B-Library
Scholar	I-Library
may	O
vary	O
by	O
discipline	O
compared	O
to	O
other	O
general	O
databases	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
strives	O
to	O
include	O
as	O
many	O
journals	O
as	O
possible	O
,	O
including	O
predatory	O
journals	O
,	O
which	O
may	O
lack	O
academic	O
rigor	O
.	O
</s>
<s>
Specialists	O
on	O
predatory	O
journals	O
say	O
that	O
these	O
kinds	O
of	O
journals	O
"	O
have	O
polluted	O
the	O
global	O
scientific	O
record	O
with	O
pseudo-science	O
"	O
and	O
"	O
that	O
Google	B-Library
Scholar	I-Library
dutifully	O
and	O
perhaps	O
blindly	O
includes	O
in	O
its	O
central	O
index.	O
"	O
</s>
<s>
Google	B-Library
Scholar	I-Library
does	O
not	O
publish	O
a	O
list	O
of	O
journals	O
crawled	O
or	O
publishers	O
included	O
,	O
and	O
the	O
frequency	O
of	O
its	O
updates	O
is	O
uncertain	O
.	O
</s>
<s>
Bibliometric	O
evidence	O
suggests	O
Google	B-Library
Scholar	I-Library
's	O
coverage	O
of	O
the	O
sciences	O
and	O
social	O
sciences	O
is	O
competitive	O
with	O
other	O
academic	B-Library
databases	I-Library
;	O
as	O
of	O
2017	O
,	O
Scholar	O
's	O
coverage	O
of	O
the	O
arts	O
and	O
humanities	O
has	O
not	O
been	O
investigated	O
empirically	O
and	O
Scholar	O
's	O
utility	O
for	O
disciplines	O
in	O
these	O
fields	O
remains	O
ambiguous	O
.	O
</s>
<s>
Elsevier	O
journals	O
have	O
been	O
included	O
since	O
mid-2007	O
,	O
when	O
Elsevier	O
began	O
to	O
make	O
most	O
of	O
its	O
ScienceDirect	O
content	O
available	O
to	O
Google	B-Library
Scholar	I-Library
and	O
Google	B-Application
's	I-Application
web	B-Application
search	I-Application
.	O
</s>
<s>
However	O
,	O
a	O
2014	O
study	O
estimates	O
that	O
Google	B-Library
Scholar	I-Library
can	O
find	O
almost	O
90%	O
(	O
approximately	O
100	O
million	O
)	O
of	O
all	O
scholarly	O
documents	O
on	O
the	O
Web	O
written	O
in	O
English	O
.	O
</s>
<s>
Large-scale	O
longitudinal	O
studies	O
have	O
found	O
between	O
40	O
and	O
60	O
percent	O
of	O
scientific	O
articles	O
are	O
available	O
in	O
full	O
text	O
via	O
Google	B-Library
Scholar	I-Library
links	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
puts	O
high	O
weight	O
on	O
citation	O
counts	O
in	O
its	O
ranking	O
algorithm	O
and	O
therefore	O
is	O
being	O
criticized	O
for	O
strengthening	O
the	O
Matthew	O
effect	O
;	O
as	O
highly	O
cited	O
papers	O
appear	O
in	O
top	O
positions	O
they	O
gain	O
more	O
citations	O
while	O
new	O
papers	O
hardly	O
appear	O
in	O
top	O
positions	O
and	O
therefore	O
get	O
less	O
attention	O
by	O
the	O
users	O
of	O
Google	B-Library
Scholar	I-Library
and	O
hence	O
fewer	O
citations	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
effect	O
is	O
a	O
phenomenon	O
when	O
some	O
researchers	O
pick	O
and	O
cite	O
works	O
appearing	O
in	O
the	O
top	O
results	O
on	O
Google	B-Library
Scholar	I-Library
regardless	O
of	O
their	O
contribution	O
to	O
the	O
citing	O
publication	O
because	O
they	O
automatically	O
assume	O
these	O
works	O
 '	O
credibility	O
and	O
believe	O
that	O
editors	O
,	O
reviewers	O
,	O
and	O
readers	O
expect	O
to	O
see	O
these	O
citations	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
has	O
problems	O
identifying	O
publications	O
on	O
the	O
arXiv	O
preprint	O
server	O
correctly	O
.	O
</s>
<s>
Interpunctuation	O
characters	O
in	O
titles	O
produce	O
wrong	O
search	B-Application
results	I-Application
,	O
and	O
authors	O
are	O
assigned	O
to	O
wrong	O
papers	O
,	O
which	O
leads	O
to	O
erroneous	O
additional	O
search	B-Application
results	I-Application
.	O
</s>
<s>
Some	O
search	B-Application
results	I-Application
are	O
even	O
given	O
without	O
any	O
comprehensible	O
reason	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
is	O
vulnerable	O
to	O
spam	O
.	O
</s>
<s>
Researchers	O
from	O
the	O
University	O
of	O
California	O
,	O
Berkeley	O
and	O
Otto-von-Guericke	O
University	O
Magdeburg	O
demonstrated	O
that	O
citation	O
counts	O
on	O
Google	B-Library
Scholar	I-Library
can	O
be	O
manipulated	O
and	O
complete	O
non-sense	O
articles	O
created	O
with	O
SCIgen	B-Application
were	O
indexed	O
within	O
Google	B-Library
Scholar	I-Library
.	O
</s>
<s>
These	O
researchers	O
concluded	O
that	O
citation	O
counts	O
from	O
Google	B-Library
Scholar	I-Library
should	O
be	O
used	O
with	O
care	O
,	O
especially	O
when	O
used	O
to	O
calculate	O
performance	O
metrics	O
such	O
as	O
the	O
h-index	O
or	O
impact	O
factor	O
,	O
which	O
is	O
in	O
itself	O
a	O
poor	O
predictor	O
of	O
article	O
quality	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
started	O
computing	O
an	O
h-index	O
in	O
2012	O
with	O
the	O
advent	O
of	O
individual	O
Scholar	O
pages	O
.	O
</s>
<s>
The	O
practicality	O
of	O
manipulating	O
h-index	O
calculators	O
by	O
spoofing	O
Google	B-Library
Scholar	I-Library
was	O
demonstrated	O
in	O
2010	O
by	O
Cyril	O
Labbe	O
from	O
Joseph	O
Fourier	O
University	O
,	O
who	O
managed	O
to	O
rank	O
"	O
Ike	O
Antkare	O
"	O
ahead	O
of	O
Albert	O
Einstein	O
by	O
means	O
of	O
a	O
large	O
set	O
of	O
SCIgen-produced	O
documents	O
citing	O
each	O
other	O
(	O
effectively	O
an	O
academic	O
link	O
farm	O
)	O
.	O
</s>
<s>
As	O
of	O
2010	O
,	O
Google	B-Library
Scholar	I-Library
was	O
not	O
able	O
to	O
shepardize	B-Library
case	O
law	O
,	O
as	O
Lexis	B-Library
could	O
.	O
</s>
<s>
Unlike	O
other	O
indexes	O
of	O
academic	O
work	O
such	O
as	O
Scopus	B-Library
and	O
Web	B-Library
of	I-Library
Science	I-Library
,	O
Google	B-Library
Scholar	I-Library
does	O
not	O
maintain	O
an	O
Application	B-Application
Programming	I-Application
Interface	I-Application
that	O
may	O
be	O
used	O
to	O
automate	O
data	O
retrieval	O
.	O
</s>
<s>
Use	O
of	O
web	O
scrapers	O
to	O
obtain	O
the	O
contents	O
of	O
search	B-Application
results	I-Application
is	O
also	O
severely	O
restricted	O
by	O
the	O
implementation	O
of	O
CAPTCHAs	O
.	O
</s>
<s>
Google	B-Library
Scholar	I-Library
does	O
not	O
display	O
or	O
export	O
Digital	O
Object	O
Identifiers	O
(	O
DOIs	O
)	O
,	O
a	O
de	O
facto	O
standard	O
implemented	O
by	O
all	O
major	O
academic	O
publishers	O
to	O
uniquely	O
identify	O
and	O
refer	O
to	O
individual	O
pieces	O
of	O
academic	O
work	O
.	O
</s>
<s>
Search	B-Application
engine	I-Application
optimization	O
(	O
SEO	O
)	O
for	O
traditional	O
web	B-Application
search	I-Application
engines	I-Application
such	O
as	O
Google	B-Application
has	O
been	O
popular	O
for	O
many	O
years	O
.	O
</s>
<s>
For	O
several	O
years	O
,	O
SEO	O
has	O
also	O
been	O
applied	O
to	O
academic	B-Library
search	I-Library
engines	I-Library
such	O
as	O
Google	B-Library
Scholar	I-Library
.	O
</s>
<s>
SEO	O
for	O
academic	O
articles	O
is	O
also	O
called	O
"	O
academic	O
search	B-Application
engine	I-Application
optimization	O
"	O
(	O
ASEO	O
)	O
and	O
defined	O
as	O
"	O
the	O
creation	O
,	O
publication	O
,	O
and	O
modification	O
of	O
scholarly	O
literature	O
in	O
a	O
way	O
that	O
makes	O
it	O
easier	O
for	O
academic	B-Library
search	I-Library
engines	I-Library
to	O
both	O
crawl	O
it	O
and	O
index	O
it	O
"	O
.	O
</s>
<s>
ASEO	O
has	O
been	O
adopted	O
by	O
several	O
organizations	O
,	O
among	O
them	O
Elsevier	O
,	O
OpenScience	O
,	O
Mendeley	B-Language
,	O
and	O
SAGE	O
Publishing	O
,	O
to	O
optimize	O
their	O
articles	O
 '	O
rankings	O
in	O
Google	B-Library
Scholar	I-Library
.	O
</s>
