<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
string	B-General_Concept
generation	I-General_Concept
is	O
the	O
process	O
of	O
creating	O
a	O
set	O
of	O
strings	O
from	O
a	O
collection	O
of	O
rules	O
.	O
</s>
<s>
This	O
is	O
an	O
opposite	O
process	O
to	O
that	O
of	O
parsing	B-Language
,	O
which	O
recognises	O
a	O
string	O
based	O
on	O
some	O
collection	O
of	O
rules	O
.	O
</s>
<s>
Applications	O
of	O
string	B-General_Concept
generation	I-General_Concept
include	O
test	B-General_Concept
data	I-General_Concept
generation	O
,	O
Captchas	O
and	O
random	O
essay	O
generation	O
.	O
</s>
<s>
Methods	O
for	O
generating	B-General_Concept
strings	I-General_Concept
include	O
:	O
</s>
<s>
While	O
a	O
deterministic	B-General_Concept
finite	I-General_Concept
automaton	I-General_Concept
is	O
often	O
used	O
to	O
recognize	O
strings	O
it	O
can	O
easily	O
be	O
changed	O
to	O
generate	O
strings	O
.	O
</s>
<s>
Unsolved	O
problems	O
in	O
string	B-General_Concept
generation	I-General_Concept
include	O
:	O
</s>
<s>
It	O
is	O
an	O
undecidable	O
problem	O
to	O
decide	O
whether	O
a	O
given	O
string	O
can	O
be	O
generated	O
by	O
a	O
given	O
W-grammar	B-Application
.	O
</s>
