<s>
A	O
datum	B-General_Concept
is	O
an	O
individual	O
value	O
in	O
a	O
collection	O
of	O
data	O
.	O
</s>
<s>
Examples	O
of	O
data	B-General_Concept
sets	I-General_Concept
include	O
price	O
indices	O
(	O
such	O
as	O
consumer	O
price	O
index	O
)	O
,	O
unemployment	O
rates	O
,	O
literacy	O
rates	O
,	O
and	O
census	O
data	O
.	O
</s>
<s>
Data	O
is	O
collected	B-General_Concept
using	O
techniques	O
such	O
as	O
measurement	O
,	O
observation	O
,	O
query	B-Library
,	O
or	O
analysis	O
,	O
and	O
typically	O
represented	O
as	O
numbers	O
or	O
characters	O
which	O
may	O
be	O
further	O
processed	B-General_Concept
.	O
</s>
<s>
Field	O
data	O
is	O
data	O
that	O
is	O
collected	B-General_Concept
in	O
an	O
uncontrolled	O
in-situ	O
environment	O
.	O
</s>
<s>
Experimental	B-General_Concept
data	I-General_Concept
is	O
data	O
that	O
is	O
generated	O
in	O
the	O
course	O
of	O
a	O
controlled	O
scientific	O
experiment	O
.	O
</s>
<s>
Data	O
is	O
analyzed	B-General_Concept
using	O
techniques	O
such	O
as	O
calculation	O
,	O
reasoning	O
,	O
discussion	O
,	O
presentation	O
,	O
visualization	B-Application
,	O
or	O
other	O
forms	O
of	O
post-analysis	O
.	O
</s>
<s>
Data	O
,	O
as	O
a	O
general	O
concept	O
,	O
refers	O
to	O
the	O
fact	O
that	O
some	O
existing	O
information	O
or	O
knowledge	O
is	O
represented	O
or	O
coded	O
in	O
some	O
form	O
suitable	O
for	O
better	O
usage	O
or	O
processing	B-General_Concept
.	O
</s>
<s>
Advances	O
in	O
computing	O
technologies	O
have	O
led	O
to	O
the	O
advent	O
of	O
big	B-Application
data	I-Application
,	O
which	O
usually	O
refers	O
to	O
very	O
large	O
quantities	O
of	O
data	O
,	O
usually	O
at	O
the	O
petabyte	O
scale	O
.	O
</s>
<s>
Using	O
traditional	O
data	B-General_Concept
analysis	I-General_Concept
methods	O
and	O
computing	O
,	O
working	O
with	O
such	O
large	O
(	O
and	O
growing	O
)	O
datasets	B-General_Concept
is	O
difficult	O
,	O
even	O
impossible	O
.	O
</s>
<s>
In	O
response	O
,	O
the	O
relatively	O
new	O
field	O
of	O
data	O
science	O
uses	O
machine	O
learning	O
(	O
and	O
other	O
artificial	B-Application
intelligence	I-Application
(	O
AI	B-Application
)	O
)	O
methods	O
that	O
allow	O
for	O
efficient	O
applications	O
of	O
analytic	O
methods	O
to	O
big	B-Application
data	I-Application
.	O
</s>
<s>
The	O
expression	O
"	O
data	B-General_Concept
processing	I-General_Concept
"	O
was	O
first	O
used	O
in	O
1954	O
.	O
</s>
<s>
This	O
usage	O
is	O
common	O
in	O
everyday	O
language	O
and	O
in	O
technical	O
and	O
scientific	O
fields	O
such	O
as	O
software	O
development	O
and	O
computer	B-General_Concept
science	I-General_Concept
.	O
</s>
<s>
One	O
example	O
of	O
this	O
usage	O
is	O
the	O
term	O
"	O
big	B-Application
data	I-Application
"	O
.	O
</s>
<s>
When	O
used	O
more	O
specifically	O
to	O
refer	O
to	O
the	O
processing	B-General_Concept
and	O
analysis	O
of	O
sets	O
of	O
data	O
,	O
the	O
term	O
retains	O
its	O
plural	O
form	O
.	O
</s>
<s>
This	O
usage	O
is	O
common	O
in	O
natural	O
sciences	O
,	O
life	O
sciences	O
,	O
social	O
sciences	O
,	O
software	O
development	O
and	O
computer	B-General_Concept
science	I-General_Concept
,	O
and	O
grew	O
in	O
popularity	O
in	O
the	O
20th	O
and	O
21st	O
centuries	O
.	O
</s>
<s>
According	O
to	O
a	O
common	O
view	O
,	O
data	O
is	O
collected	B-General_Concept
and	O
analyzed	B-General_Concept
;	O
data	O
only	O
becomes	O
information	O
suitable	O
for	O
making	O
decisions	O
once	O
it	O
has	O
been	O
analyzed	B-General_Concept
in	O
some	O
fashion	O
.	O
</s>
<s>
One	O
can	O
say	O
that	O
the	O
extent	O
to	O
which	O
a	O
set	B-General_Concept
of	I-General_Concept
data	I-General_Concept
is	O
informative	O
to	O
someone	O
depends	O
on	O
the	O
extent	O
to	O
which	O
it	O
is	O
unexpected	O
by	O
that	O
person	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
entry	O
in	O
a	O
database	O
specifying	O
the	O
height	O
of	O
Mount	O
Everest	O
is	O
a	O
datum	B-General_Concept
that	O
communicates	O
a	O
precisely-measured	O
value	O
.	O
</s>
<s>
An	O
analog	O
computer	O
represents	O
a	O
datum	B-General_Concept
as	O
a	O
voltage	O
,	O
distance	O
,	O
position	O
,	O
or	O
other	O
physical	O
quantity	O
.	O
</s>
<s>
A	O
digital	O
computer	O
represents	O
a	O
piece	O
of	O
data	O
as	O
a	O
sequence	O
of	O
symbols	O
drawn	O
from	O
a	O
fixed	O
alphabet	B-Application
.	O
</s>
<s>
The	O
most	O
common	O
digital	O
computers	O
use	O
a	O
binary	O
alphabet	B-Application
,	O
that	O
is	O
,	O
an	O
alphabet	B-Application
of	O
two	O
characters	O
typically	O
denoted	O
"	O
0	O
"	O
and	O
"	O
1	O
"	O
.	O
</s>
<s>
More	O
familiar	O
representations	O
,	O
such	O
as	O
numbers	O
or	O
letters	O
,	O
are	O
then	O
constructed	O
from	O
the	O
binary	O
alphabet	B-Application
.	O
</s>
<s>
A	O
computer	B-Application
program	I-Application
is	O
a	O
collection	O
of	O
data	O
,	O
which	O
can	O
be	O
interpreted	O
as	O
instructions	O
.	O
</s>
<s>
Most	O
computer	O
languages	O
make	O
a	O
distinction	O
between	O
programs	O
and	O
the	O
other	O
data	O
on	O
which	O
programs	O
operate	O
,	O
but	O
in	O
some	O
languages	O
,	O
notably	O
Lisp	B-Language
and	O
similar	O
languages	O
,	O
programs	O
are	O
essentially	O
indistinguishable	O
from	O
other	O
data	O
.	O
</s>
<s>
Some	O
of	O
these	O
data	O
documents	O
(	O
data	O
repositories	O
,	O
data	O
studies	O
,	O
data	B-General_Concept
sets	I-General_Concept
,	O
and	O
software	O
)	O
are	O
indexed	O
in	O
Data	O
Citation	O
Indexes	O
,	O
while	O
data	B-Application
papers	I-Application
are	O
indexed	O
in	O
traditional	O
bibliographic	O
databases	O
,	O
e.g.	O
,	O
Science	B-Library
Citation	I-Library
Index	I-Library
.	O
</s>
<s>
Gathering	O
data	O
can	O
be	O
accomplished	O
through	O
a	O
primary	O
source	O
(	O
the	O
researcher	O
is	O
the	O
first	O
person	O
to	O
obtain	O
the	O
data	O
)	O
or	O
a	O
secondary	O
source	O
(	O
the	O
researcher	O
obtains	O
the	O
data	O
that	O
has	O
already	O
been	O
collected	B-General_Concept
by	O
other	O
sources	O
,	O
such	O
as	O
data	O
disseminated	O
in	O
a	O
scientific	O
journal	O
)	O
.	O
</s>
<s>
Data	B-General_Concept
analysis	I-General_Concept
methodologies	O
vary	O
and	O
include	O
data	O
triangulation	O
and	O
data	O
percolation	O
.	O
</s>
<s>
An	O
important	O
field	O
in	O
computer	B-General_Concept
science	I-General_Concept
,	O
technology	B-General_Concept
,	O
and	O
library	O
science	O
is	O
the	O
longevity	O
of	O
data	O
.	O
</s>
<s>
in	O
medical	B-Application
imaging	I-Application
.	O
</s>
<s>
In	O
the	O
past	O
,	O
scientific	B-General_Concept
data	I-General_Concept
has	O
been	O
published	O
in	O
papers	O
and	O
books	O
,	O
stored	O
in	O
libraries	O
,	O
but	O
more	O
recently	O
practically	O
all	O
data	O
is	O
stored	O
on	O
hard	B-Device
drives	I-Device
or	O
optical	B-Device
discs	I-Device
.	O
</s>
<s>
Another	O
problem	O
is	O
that	O
much	O
scientific	B-General_Concept
data	I-General_Concept
is	O
never	O
published	O
or	O
deposited	O
in	O
data	O
repositories	O
such	O
as	O
databases	O
.	O
</s>
<s>
Similarly	O
,	O
a	O
survey	O
of	O
100	O
datasets	B-General_Concept
in	O
Dryad	O
found	O
that	O
more	O
than	O
half	O
lacked	O
the	O
details	O
to	O
reproduce	O
the	O
research	O
results	O
from	O
these	O
studies	O
.	O
</s>
<s>
This	O
shows	O
the	O
dire	O
situation	O
of	O
access	O
to	O
scientific	B-General_Concept
data	I-General_Concept
that	O
is	O
not	O
published	O
or	O
does	O
not	O
have	O
enough	O
details	O
to	O
be	O
reproduced	O
.	O
</s>
<s>
Data	O
that	O
fulfills	O
these	O
requirements	O
can	O
be	O
used	O
in	O
subsequent	O
research	O
and	O
thus	O
advances	O
science	O
and	O
technology	B-General_Concept
.	O
</s>
