<s>
Google	B-Application
Personalized	I-Application
Search	I-Application
is	O
a	O
personalized	B-Application
search	I-Application
feature	O
of	O
Google	B-Application
Search	I-Application
,	O
introduced	O
in	O
2004	O
.	O
</s>
<s>
All	O
searches	O
on	O
Google	B-Application
Search	I-Application
are	O
associated	O
with	O
a	O
browser	B-Application
cookie	I-Application
record	O
.	O
</s>
<s>
When	O
a	O
user	O
performs	O
a	O
search	O
,	O
the	O
search	O
results	O
are	O
not	O
only	O
based	O
on	O
the	O
relevance	O
of	O
each	O
web	O
page	O
to	O
the	O
search	O
term	O
,	O
but	O
also	O
on	O
which	O
websites	O
the	O
user	O
(	O
or	O
someone	O
else	O
using	O
the	O
same	O
browser	B-Application
)	O
visited	O
through	O
previous	O
search	O
results	O
.	O
</s>
<s>
Such	O
filtering	O
may	O
also	O
have	O
side	O
effects	O
,	O
such	O
as	O
the	O
creation	O
of	O
a	O
filter	B-Algorithm
bubble	I-Algorithm
.	O
</s>
<s>
Changes	O
in	O
Google	B-Application
's	O
search	O
algorithm	O
in	O
later	O
years	O
put	O
less	O
importance	O
on	O
user	O
data	O
,	O
which	O
means	O
the	O
impact	O
of	O
personalized	B-Application
search	I-Application
is	O
limited	O
on	O
search	O
results	O
.	O
</s>
<s>
Acting	O
on	O
criticism	O
,	O
Google	B-Application
has	O
also	O
made	O
it	O
possible	O
to	O
turn	O
off	O
the	O
feature	O
.	O
</s>
<s>
Personalized	B-Application
Search	I-Application
was	O
originally	O
introduced	O
on	O
March	O
29	O
,	O
2004	O
as	O
a	O
beta	O
test	O
of	O
a	O
Google	B-Application
Labs	I-Application
project	O
.	O
</s>
<s>
On	O
April	O
20	O
,	O
2005	O
,	O
it	O
was	O
made	O
available	O
as	O
a	O
non-beta	O
service	O
,	O
but	O
still	O
separate	O
from	O
ordinary	O
Google	B-Application
Search	I-Application
.	O
</s>
<s>
On	O
November	O
11	O
,	O
2005	O
,	O
it	O
became	O
a	O
part	O
of	O
the	O
normal	O
Google	B-Application
Search	I-Application
,	O
but	O
only	O
to	O
users	O
with	O
Google	B-Application
Accounts	I-Application
.	O
</s>
<s>
Beginning	O
on	O
December	O
4	O
,	O
2009	O
,	O
Personalized	B-Application
Search	I-Application
was	O
applied	O
to	O
all	O
users	O
of	O
Google	B-Application
Search	I-Application
,	O
including	O
those	O
who	O
are	O
not	O
logged	O
into	O
a	O
Google	B-Application
Account	I-Application
.	O
</s>
<s>
In	O
addition	O
to	O
customizing	O
results	O
based	O
on	O
personal	O
behavior	O
and	O
interests	O
associated	O
with	O
a	O
Google	B-Application
Account	I-Application
,	O
Google	B-Application
also	O
implemented	O
social	O
search	O
results	O
in	O
October	O
2009	O
based	O
on	O
people	O
whom	O
one	O
knows	O
.	O
</s>
<s>
Google	B-Application
's	O
search	O
algorithm	O
is	O
driven	O
by	O
collecting	O
and	O
storing	O
web	O
history	O
in	O
its	O
databases	O
.	O
</s>
<s>
For	O
non-authenticated	O
users	O
Google	B-Application
looks	O
at	O
anonymously	O
stored	O
browser	B-Application
cookies	I-Application
on	O
a	O
user	O
's	O
browser	B-Application
and	O
compares	O
the	O
unique	O
string	O
with	O
those	O
stored	O
within	O
Google	B-Application
databases	O
.	O
</s>
<s>
Google	B-Application
accounts	I-Application
logged	O
into	O
Google	B-Application
Chrome	I-Application
use	O
user	O
's	O
web	O
history	O
to	O
learn	O
what	O
sites	O
and	O
content	O
you	O
like	O
and	O
base	O
the	O
search	O
results	O
presented	O
on	O
them	O
.	O
</s>
<s>
Using	O
the	O
data	O
provided	O
by	O
the	O
user	O
Google	B-Application
constructs	O
a	O
profile	O
including	O
gender	O
,	O
age	O
,	O
languages	O
,	O
and	O
interests	O
based	O
on	O
prior	O
behaviour	O
using	O
Google	B-Application
services	O
.	O
</s>
<s>
When	O
a	O
user	O
performs	O
a	O
search	O
using	O
Google	B-Application
,	O
the	O
keywords	O
or	O
terms	O
are	O
used	O
to	O
generate	O
ranked	O
results	O
based	O
upon	O
the	O
PageRank	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
This	O
algorithm	O
,	O
according	O
to	O
Google	B-Application
,	O
is	O
their	O
"	O
system	O
of	O
counting	O
link	O
votes	O
and	O
determining	O
which	O
pages	O
are	O
most	O
important	O
based	O
upon	O
them	O
.	O
</s>
<s>
"	O
PageRank	B-Algorithm
relies	O
on	O
the	O
uniquely	O
democratic	O
nature	O
of	O
the	O
web	O
by	O
using	O
its	O
vast	O
link	O
structure	O
as	O
an	O
indicator	O
of	O
an	O
individual	O
page	O
's	O
value	O
.	O
</s>
<s>
In	O
essence	O
,	O
Google	B-Application
interprets	O
a	O
link	O
from	O
page	O
A	O
to	O
page	O
B	O
as	O
a	O
vote	O
,	O
by	O
page	O
A	O
,	O
for	O
page	O
B	O
.	O
</s>
<s>
But	O
,	O
Google	B-Application
looks	O
at	O
considerably	O
more	O
than	O
the	O
sheer	O
volume	O
of	O
votes	O
,	O
or	O
links	O
a	O
page	O
receives	O
;	O
for	O
example	O
,	O
it	O
also	O
analyzes	O
the	O
page	O
that	O
casts	O
the	O
vote	O
.	O
</s>
<s>
Using	O
these	O
and	O
other	O
factors	O
,	O
Google	B-Application
provides	O
its	O
views	O
on	O
the	O
pages	O
 '	O
relative	O
importance	O
,	O
"	O
</s>
<s>
According	O
to	O
Google	B-Application
,	O
the	O
conclusion	O
they	O
have	O
made	O
after	O
many	O
years	O
of	O
testing	O
,	O
the	O
incomparably	O
best	O
indicator	O
for	O
deciding	O
which	O
results	O
are	O
relevant	O
to	O
the	O
user	O
is	O
the	O
search	O
phrase	O
itself	O
-	O
not	O
user	O
data	O
-	O
and	O
that	O
personalisation	O
of	O
search	O
results	O
is	O
not	O
as	O
big	O
a	O
factor	O
as	O
it	O
used	O
to	O
be	O
.	O
</s>
<s>
Harvard	O
law	O
professor	O
Jonathan	O
Zittrain	O
disputed	O
the	O
extent	O
to	O
which	O
personalization	O
filters	O
distort	O
Google	B-Application
search	I-Application
results	O
,	O
saying	O
that	O
"	O
the	O
effects	O
of	O
search	O
personalization	O
have	O
been	O
light	O
"	O
.	O
</s>
<s>
Further	O
,	O
Google	B-Application
provides	O
the	O
ability	O
for	O
users	O
to	O
shut	O
off	O
personalization	O
features	O
if	O
they	O
choose	O
,	O
by	O
deleting	O
Google	B-Application
's	O
record	O
of	O
their	O
search	O
history	O
and	O
setting	O
Google	B-Application
to	O
not	O
remember	O
their	O
search	O
keywords	O
and	O
visited	O
links	O
in	O
the	O
future	O
.	O
</s>
<s>
There	O
are	O
50+	O
factors	O
(	O
called	O
'	O
signals	O
 '	O
by	O
Google	B-Application
)	O
used	O
to	O
determine	O
search	O
results	O
.	O
</s>
<s>
Location	O
data	O
allows	O
Google	B-Application
to	O
provide	O
information	O
based	O
upon	O
current	O
location	O
and	O
places	O
that	O
the	O
user	O
has	O
visited	O
in	O
the	O
past	O
,	O
based	O
upon	O
GPS	O
location	O
from	O
an	O
Android	O
smartphone	O
or	O
the	O
user	O
's	O
IP	O
address	O
.	O
</s>
<s>
Google	B-Application
uses	O
this	O
location	O
data	O
to	O
provide	O
local	O
listings	O
grouped	O
with	O
search	O
results	O
using	O
the	O
Google	B-Application
Local	O
platform	O
featuring	O
detailed	O
reviews	O
and	O
ratings	O
from	O
Zagat	O
.	O
</s>
<s>
Then	O
,	O
in	O
2009	O
,	O
Google	B-Application
announced	O
that	O
personalized	B-Application
search	I-Application
would	O
no	O
longer	O
require	O
a	O
user	O
to	O
be	O
logged	O
in	O
,	O
and	O
instead	O
Google	B-Application
would	O
use	O
an	O
anonymous	O
cookie	B-Application
in	O
a	O
web	B-Application
browser	I-Application
to	O
customize	O
search	O
results	O
for	O
those	O
who	O
were	O
not	O
logged	O
in	O
.	O
</s>
<s>
Lastly	O
,	O
Google+	B-Application
data	O
is	O
used	O
in	O
search	O
results	O
as	O
Google	B-Application
is	O
provided	O
a	O
lot	O
of	O
demographics	O
about	O
a	O
user	O
from	O
this	O
information	O
,	O
such	O
as	O
age	O
,	O
gender	O
,	O
location	O
,	O
work	O
history	O
,	O
interests	O
,	O
and	O
social	O
connections	O
.	O
</s>
<s>
Google	B-Application
's	O
social	O
networking	O
service	O
,	O
Google+	B-Application
also	O
collects	O
this	O
demographic	O
data	O
including	O
age	O
,	O
sex	O
,	O
location	O
,	O
career	O
,	O
and	O
friends	O
.	O
</s>
<s>
The	O
study	O
showed	O
that	O
of	O
the	O
various	O
factors	O
being	O
tested	O
,	O
the	O
two	O
with	O
the	O
most	O
measurable	O
impact	O
were	O
whether	O
the	O
user	O
was	O
logged	O
in	O
with	O
a	O
Google	B-Application
account	I-Application
and	O
the	O
IP	O
address	O
of	O
searching	O
users	O
.	O
</s>
<s>
Personalized	B-Application
search	I-Application
suffers	O
from	O
creating	O
an	O
abundance	O
of	O
background	O
noise	O
to	O
search	O
results	O
.	O
</s>
<s>
However	O
,	O
in	O
recent	O
years	O
new	O
research	O
had	O
stated	O
that	O
search	O
engines	O
do	O
not	O
create	O
the	O
kind	O
of	O
filter	B-Algorithm
bubbles	I-Algorithm
previously	O
thought	O
.	O
</s>
<s>
The	O
researchers	O
note	O
that	O
filter	B-Algorithm
bubbles	I-Algorithm
sound	O
like	O
a	O
real	O
problem	O
and	O
that	O
they	O
primarily	O
appear	O
to	O
apply	O
to	O
people	O
other	O
than	O
yourself	O
.	O
</s>
<s>
Their	O
conclusion	O
is	O
,	O
nonetheless	O
,	O
that	O
the	O
problem	O
is	O
overblown	O
,	O
the	O
evidence	O
anecdotal	O
,	O
and	O
it	O
is	O
impossible	O
to	O
see	O
that	O
search	O
engines	O
contribute	O
to	O
the	O
creation	O
of	O
filter	B-Algorithm
bubbles	I-Algorithm
based	O
on	O
the	O
empirical	O
evidence	O
produced	O
by	O
the	O
study	O
.	O
</s>
