<s>
Social	B-General_Concept
bookmarking	I-General_Concept
is	O
an	O
online	O
service	O
which	O
allows	O
users	O
to	O
add	O
,	O
annotate	O
,	O
edit	O
,	O
and	O
share	O
bookmarks	O
of	O
web	O
documents	O
.	O
</s>
<s>
Many	O
online	O
bookmark	B-Application
management	I-Application
services	O
have	O
launched	O
since	O
1996	O
;	O
Delicious	B-Application
,	O
founded	O
in	O
2003	O
,	O
popularized	O
the	O
terms	O
"	O
social	B-General_Concept
bookmarking	I-General_Concept
"	O
and	O
"	O
tagging	B-General_Concept
"	O
.	O
</s>
<s>
Tagging	B-General_Concept
is	O
a	O
significant	O
feature	O
of	O
social	B-General_Concept
bookmarking	I-General_Concept
systems	O
,	O
allowing	O
users	O
to	O
organize	O
their	O
bookmarks	O
and	O
develop	O
shared	O
vocabularies	O
known	O
as	O
folksonomies	B-General_Concept
.	O
</s>
<s>
Unlike	O
file	O
sharing	O
,	O
social	B-General_Concept
bookmarking	I-General_Concept
does	O
not	O
save	O
the	O
resources	O
themselves	O
,	O
merely	O
bookmarks	O
that	O
reference	O
them	O
,	O
i.e.	O
</s>
<s>
Such	O
descriptions	O
may	O
be	O
free	O
text	O
comments	O
,	O
votes	O
in	O
favor	O
of	O
or	O
against	O
its	O
quality	O
,	O
or	O
tags	B-General_Concept
that	O
collectively	O
or	O
collaboratively	O
become	O
a	O
folksonomy	B-General_Concept
.	O
</s>
<s>
Folksonomy	B-General_Concept
is	O
also	O
called	O
social	B-General_Concept
tagging	I-General_Concept
,	O
"	O
the	O
process	O
by	O
which	O
many	O
users	O
add	O
metadata	O
in	O
the	O
form	O
of	O
keywords	O
to	O
shared	O
content	O
"	O
.	O
</s>
<s>
In	O
a	O
social	B-General_Concept
bookmarking	I-General_Concept
system	O
,	O
users	O
save	O
links	O
to	O
web	O
pages	O
that	O
they	O
want	O
to	O
remember	O
and/or	O
share	O
.	O
</s>
<s>
These	O
bookmarks	O
are	O
usually	O
public	O
,	O
and	O
can	O
be	O
saved	O
privately	O
,	O
shared	O
only	O
with	O
specified	O
people	O
or	O
groups	O
,	O
shared	O
only	O
inside	O
certain	O
networks	B-Architecture
,	O
or	O
another	O
combination	O
of	O
public	O
and	O
private	O
domains	O
.	O
</s>
<s>
The	O
allowed	O
people	O
can	O
usually	O
view	O
these	O
bookmarks	O
chronologically	O
,	O
by	O
category	O
or	O
tags	B-General_Concept
,	O
or	O
via	O
a	O
search	B-Application
engine	I-Application
.	O
</s>
<s>
Most	O
social	B-General_Concept
bookmark	I-General_Concept
services	O
encourage	O
users	O
to	O
organize	O
their	O
bookmarks	O
with	O
informal	O
tags	B-General_Concept
instead	O
of	O
the	O
traditional	O
browser-based	O
system	O
of	O
folders	O
,	O
although	O
some	O
services	O
feature	O
categories/folders	O
or	O
a	O
combination	O
of	O
folders	O
and	O
tags	B-General_Concept
.	O
</s>
<s>
They	O
also	O
enable	O
viewing	O
bookmarks	O
associated	O
with	O
a	O
chosen	O
tag	B-General_Concept
,	O
and	O
include	O
information	O
about	O
the	O
number	O
of	O
users	O
who	O
have	O
bookmarked	O
them	O
.	O
</s>
<s>
Some	O
social	B-General_Concept
bookmarking	I-General_Concept
services	O
also	O
draw	O
inferences	O
from	O
the	O
relationship	O
of	O
tags	B-General_Concept
to	O
create	O
clusters	O
of	O
tags	B-General_Concept
or	O
bookmarks	O
.	O
</s>
<s>
Many	O
social	B-General_Concept
bookmarking	I-General_Concept
services	O
provide	O
web	B-General_Concept
feeds	I-General_Concept
for	O
their	O
lists	O
of	O
bookmarks	O
,	O
including	O
lists	O
organized	O
by	O
tags	B-General_Concept
.	O
</s>
<s>
As	O
these	O
services	O
have	O
matured	O
and	O
grown	O
more	O
popular	O
,	O
they	O
have	O
added	O
extra	O
features	O
such	O
as	O
ratings	O
and	O
comments	O
on	O
bookmarks	O
,	O
the	O
ability	O
to	O
import	O
and	O
export	O
bookmarks	O
from	O
browsers	O
,	O
emailing	O
of	O
bookmarks	O
,	O
web	B-Protocol
annotation	I-Protocol
,	O
and	O
groups	O
or	O
other	O
social	O
network	O
features	O
.	O
</s>
<s>
WebTagger	O
included	O
several	O
advanced	O
social	B-General_Concept
bookmarking	I-General_Concept
features	O
including	O
the	O
ability	O
to	O
collaboratively	O
share	O
and	O
organize	O
bookmarks	O
using	O
a	O
web-based	O
interface	O
,	O
provide	O
comments	O
and	O
organize	O
them	O
according	O
to	O
categories	O
.	O
</s>
<s>
Lacking	O
viable	O
revenue	O
models	O
,	O
this	O
early	O
generation	O
of	O
social	B-General_Concept
bookmarking	I-General_Concept
companies	O
failed	O
as	O
the	O
dot-com	O
bubble	O
burst	O
—	O
Backflip	O
closed	O
citing	O
"	O
economic	O
woes	O
at	O
the	O
start	O
of	O
the	O
21st	O
century	O
"	O
.	O
</s>
<s>
Founded	O
in	O
2003	O
,	O
Delicious	B-Application
(	O
then	O
called	O
del.icio.us	B-Application
)	O
pioneered	O
tagging	B-General_Concept
and	O
coined	O
the	O
term	O
social	B-General_Concept
bookmarking	I-General_Concept
.	O
</s>
<s>
Frassle	O
,	O
a	O
blogging	O
system	O
released	O
in	O
November	O
2003	O
,	O
included	O
social	B-General_Concept
bookmarking	I-General_Concept
elements	O
.	O
</s>
<s>
In	O
2004	O
,	O
as	O
Delicious	B-Application
began	O
to	O
take	O
off	O
,	O
similar	O
services	O
Furl	O
,	O
Simpy	B-Application
,	O
Spurl.net,	O
and	O
unalog	O
were	O
released	O
,	O
along	O
with	O
CiteULike	B-Application
and	O
Connotea	B-Protocol
(	O
sometimes	O
called	O
social	O
citation	O
services	O
)	O
and	O
the	O
related	O
recommendation	O
system	O
Stumbleupon	O
.	O
</s>
<s>
Also	O
in	O
2004	O
,	O
the	O
social	O
photo	O
sharing	O
website	O
Flickr	B-Algorithm
was	O
released	O
,	O
and	O
inspired	O
by	O
Delicious	B-Application
it	O
soon	O
added	O
a	O
tagging	B-General_Concept
feature	O
.	O
</s>
<s>
In	O
2006	O
,	O
Ma.gnolia	O
(	O
later	O
renamed	O
to	O
Gnolia	O
)	O
,	O
Blue	O
Dot	O
(	O
later	O
renamed	O
to	O
Faves	O
)	O
,	O
Mister	O
Wong	O
,	O
and	O
Diigo	O
entered	O
the	O
bookmarking	O
field	O
,	O
and	O
Connectbeam	O
included	O
a	O
social	B-General_Concept
bookmarking	I-General_Concept
and	O
tagging	B-General_Concept
service	O
aimed	O
at	O
businesses	O
and	O
enterprises	O
.	O
</s>
<s>
In	O
2007	O
,	O
IBM	O
released	O
its	O
Lotus	B-Protocol
Connections	I-Protocol
product	O
.	O
</s>
<s>
As	O
of	O
2012	O
,	O
Furl	O
,	O
Simpy	B-Application
,	O
Spurl.net,	O
Gnolia	O
,	O
Faves	O
,	O
and	O
Connectbeam	O
are	O
no	O
longer	O
active	O
services	O
.	O
</s>
<s>
Digg	B-Application
was	O
founded	O
in	O
2004	O
with	O
a	O
related	O
system	O
for	O
sharing	O
and	O
ranking	O
social	O
news	O
,	O
followed	O
by	O
competitors	O
Reddit	B-Application
in	O
2005	O
and	O
Newsvine	O
in	O
2006	O
.	O
</s>
<s>
As	O
of	O
January	O
20	O
,	O
2016	O
,	O
Reddit	B-Application
is	O
now	O
the	O
32nd	O
highest	O
ranking	O
in	O
the	O
world	O
and	O
Digg	B-Application
is	O
no	O
longer	O
a	O
social	B-General_Concept
bookmarking	I-General_Concept
platform	O
and	O
has	O
dropped	O
out	O
of	O
the	O
top	O
1000	O
.	O
</s>
<s>
A	O
simple	O
form	O
of	O
shared	O
vocabularies	O
does	O
emerge	O
in	O
social	B-General_Concept
bookmarking	I-General_Concept
systems	O
(	O
folksonomy	B-General_Concept
)	O
.	O
</s>
<s>
Collaborative	B-General_Concept
tagging	I-General_Concept
exhibits	O
a	O
form	O
of	O
complex	O
systems	O
(	O
or	O
self-organizing	O
)	O
dynamics	O
.	O
</s>
<s>
Although	O
there	O
is	O
no	O
central	O
controlled	O
vocabulary	O
to	O
constrain	O
the	O
actions	O
of	O
individual	O
users	O
,	O
the	O
distributions	O
of	O
tags	B-General_Concept
that	O
describe	O
different	O
resources	O
have	O
been	O
shown	O
to	O
converge	O
over	O
time	O
to	O
stable	O
power	O
law	O
distributions	O
.	O
</s>
<s>
Once	O
such	O
stable	O
distributions	O
form	O
,	O
the	O
correlations	O
between	O
different	O
tags	B-General_Concept
can	O
be	O
examined	O
to	O
construct	O
simple	O
folksonomy	B-General_Concept
graphs	O
,	O
which	O
can	O
be	O
efficiently	O
partitioned	O
to	O
obtain	O
a	O
form	O
of	O
community	O
or	O
shared	O
vocabularies	O
.	O
</s>
<s>
From	O
the	O
point	O
of	O
view	O
of	O
search	O
data	O
,	O
there	O
are	O
drawbacks	O
to	O
such	O
tag-based	O
systems	O
:	O
no	O
standard	O
set	O
of	O
keywords	O
(	O
i.e.	O
,	O
a	O
folksonomy	B-General_Concept
instead	O
of	O
a	O
controlled	O
vocabulary	O
)	O
,	O
no	O
standard	O
for	O
the	O
structure	O
of	O
such	O
tags	B-General_Concept
(	O
e.g.	O
,	O
singular	O
vs.	O
plural	O
,	O
capitalization	O
)	O
,	O
mistagging	O
due	O
to	O
spelling	O
errors	O
,	O
tags	B-General_Concept
that	O
can	O
have	O
more	O
than	O
one	O
meaning	O
,	O
unclear	O
tags	B-General_Concept
due	O
to	O
synonym/antonym	O
confusion	O
,	O
unorthodox	O
and	O
personalized	O
tag	B-General_Concept
schemata	O
from	O
some	O
users	O
,	O
and	O
no	O
mechanism	O
for	O
users	O
to	O
indicate	O
hierarchical	O
relationships	O
between	O
tags	B-General_Concept
(	O
e.g.	O
,	O
a	O
site	O
might	O
be	O
labeled	O
as	O
both	O
cheese	O
and	O
cheddar	O
,	O
with	O
no	O
mechanism	O
that	O
might	O
indicate	O
that	O
cheddar	O
is	O
a	O
refinement	O
or	O
sub-class	O
of	O
cheeses	O
)	O
.	O
</s>
<s>
For	O
individual	O
users	O
,	O
social	B-General_Concept
bookmarking	I-General_Concept
can	O
be	O
useful	O
as	O
a	O
way	O
to	O
access	O
a	O
consolidated	O
set	O
of	O
bookmarks	O
from	O
various	O
computers	O
,	O
organize	O
large	O
numbers	O
of	O
bookmarks	O
,	O
and	O
share	O
bookmarks	O
with	O
contacts	O
.	O
</s>
<s>
Institutions	O
including	O
businesses	O
,	O
libraries	O
,	O
and	O
universities	O
have	O
used	O
social	B-General_Concept
bookmarking	I-General_Concept
as	O
a	O
way	O
to	O
increase	O
information	O
sharing	O
among	O
members	O
.	O
</s>
<s>
Social	B-General_Concept
bookmarking	I-General_Concept
has	O
also	O
been	O
used	O
to	O
improve	O
web	B-Application
search	I-Application
.	O
</s>
<s>
Libraries	O
have	O
found	O
social	B-General_Concept
bookmarking	I-General_Concept
to	O
be	O
useful	O
as	O
an	O
easy	O
way	O
to	O
provide	O
lists	O
of	O
informative	O
links	O
to	O
patrons	O
.	O
</s>
<s>
Social	B-General_Concept
bookmarking	I-General_Concept
tools	O
are	O
an	O
emerging	O
educational	O
technology	O
that	O
has	O
been	O
drawing	O
more	O
of	O
educators	O
 '	O
attention	O
over	O
the	O
last	O
several	O
years	O
.	O
</s>
<s>
For	O
example	O
,	O
Delicious	B-Application
could	O
be	O
used	O
in	O
a	O
course	O
to	O
provide	O
an	O
inexpensive	O
answer	O
to	O
the	O
question	O
of	O
rising	O
course	O
materials	O
costs	O
.	O
</s>
<s>
RISAL	O
(	O
Repository	O
of	O
Interactive	O
Social	O
Assets	O
for	O
Learning	O
)	O
is	O
another	O
social	B-General_Concept
bookmarking	I-General_Concept
system	O
used	O
for	O
supporting	O
teaching	O
and	O
learning	O
at	O
the	O
university	O
level	O
.	O
</s>
<s>
Social	B-General_Concept
bookmarking	I-General_Concept
tools	O
have	O
several	O
purposes	O
in	O
an	O
academic	O
setting	O
including	O
:	O
organizing	O
and	O
categorizing	O
web	O
pages	O
for	O
efficient	O
retrieval	O
;	O
keeping	O
tagged	O
pages	O
accessible	O
from	O
any	O
networked	O
computer	O
;	O
sharing	O
needed	O
or	O
desired	O
resources	O
with	O
other	O
users	O
;	O
accessing	O
tagged	O
pages	O
with	O
RSS	O
feeds	O
,	O
cell	O
phones	O
and	O
PDAs	O
for	O
increased	O
mobility	O
;	O
allowing	O
librarians	O
and	O
instructors	O
the	O
capability	O
to	O
follow	O
students	O
 '	O
progress	O
;	O
and	O
giving	O
students	O
another	O
way	O
to	O
collaborate	O
with	O
each	O
other	O
and	O
make	O
collective	O
discoveries	O
.	O
</s>
<s>
It	O
also	O
demonstrates	O
integration	O
with	O
traditional	O
learning	B-Application
content	I-Application
repositories	I-Application
,	O
such	O
as	O
Jorum	O
,	O
NLN	O
,	O
Intute	O
and	O
TES	O
.	O
</s>
<s>
In	O
comparison	O
to	O
search	B-Application
engines	I-Application
,	O
a	O
social	B-General_Concept
bookmarking	I-General_Concept
system	O
has	O
several	O
advantages	O
over	O
traditional	O
automated	O
resource	O
location	O
and	O
classification	O
software	O
,	O
such	O
as	O
search	B-Application
engine	I-Application
spiders	I-Application
.	O
</s>
<s>
All	O
tag-based	O
classification	O
of	O
Internet	O
resources	O
(	O
such	O
as	O
web	O
sites	O
)	O
is	O
done	O
by	O
human	O
beings	O
,	O
who	O
understand	O
the	O
content	O
of	O
the	O
resource	O
,	O
as	O
opposed	O
to	O
software	O
,	O
which	O
algorithmically	O
attempts	O
to	O
determine	O
the	O
meaning	O
and	O
quality	O
of	O
a	O
resource	O
.	O
</s>
<s>
Also	O
,	O
people	O
can	O
find	O
and	O
bookmark	O
web	O
pages	O
that	O
have	O
not	O
yet	O
been	O
noticed	O
or	O
indexed	O
by	O
web	B-Application
spiders	I-Application
.	O
</s>
<s>
Additionally	O
,	O
a	O
social	B-General_Concept
bookmarking	I-General_Concept
system	O
can	O
rank	O
a	O
resource	O
based	O
on	O
how	O
many	O
times	O
it	O
has	O
been	O
bookmarked	O
by	O
users	O
,	O
which	O
may	O
be	O
a	O
more	O
useful	O
metric	O
for	O
end-users	O
than	O
systems	O
that	O
rank	O
resources	O
based	O
on	O
the	O
number	O
of	O
external	O
links	O
pointing	O
to	O
it	O
.	O
</s>
<s>
Social	B-General_Concept
bookmarking	I-General_Concept
is	O
susceptible	O
to	O
corruption	O
and	O
collusion	O
.	O
</s>
<s>
Due	O
to	O
its	O
popularity	O
,	O
some	O
have	O
begun	O
to	O
use	O
it	O
as	O
a	O
tool	O
to	O
use	O
along	O
with	O
search	B-Application
engine	I-Application
optimization	O
to	O
make	O
their	O
website	O
more	O
visible	O
.	O
</s>
<s>
Spammers	O
have	O
started	O
bookmarking	O
the	O
same	O
web	O
page	O
multiple	O
times	O
and/or	O
tagging	B-General_Concept
each	O
page	O
of	O
their	O
web	O
site	O
using	O
a	O
lot	O
of	O
popular	O
tags	B-General_Concept
,	O
obligating	O
developers	O
to	O
constantly	O
adjust	O
their	O
security	O
system	O
to	O
overcome	O
abuses	O
.	O
</s>
<s>
Furthermore	O
,	O
since	O
social	B-General_Concept
bookmarking	I-General_Concept
generates	O
backlinks	O
,	O
social	B-General_Concept
bookmark	I-General_Concept
link	O
generating	O
services	O
are	O
used	O
by	O
some	O
webmasters	O
in	O
an	O
attempt	O
to	O
improve	O
their	O
websites	O
 '	O
rankings	O
in	O
search	B-Application
engine	I-Application
results	O
pages	O
.	O
</s>
