<s>
Lexical	B-General_Concept
density	I-General_Concept
is	O
a	O
concept	O
in	O
computational	O
linguistics	O
that	O
measures	O
the	O
structure	O
and	O
complexity	O
of	O
human	O
communication	O
in	O
a	O
language	O
.	O
</s>
<s>
Lexical	B-General_Concept
density	I-General_Concept
estimates	O
the	O
linguistic	O
complexity	O
in	O
a	O
written	O
or	O
spoken	O
composition	O
from	O
the	O
functional	O
words	O
(	O
grammatical	O
units	O
)	O
and	O
content	O
words	O
(	O
lexical	O
units	O
,	O
lexemes	O
)	O
.	O
</s>
<s>
One	O
method	O
to	O
calculate	O
the	O
lexical	B-General_Concept
density	I-General_Concept
is	O
to	O
compute	O
the	O
ratio	O
of	O
lexical	O
items	O
to	O
the	O
total	O
number	O
of	O
words	O
.	O
</s>
<s>
The	O
lexical	B-General_Concept
density	I-General_Concept
for	O
an	O
individual	O
evolves	O
with	O
age	O
,	O
education	O
,	O
communication	O
style	O
,	O
circumstances	O
,	O
unusual	O
injuries	O
or	O
medical	O
condition	O
,	O
and	O
his	O
or	O
her	O
creativity	O
.	O
</s>
<s>
The	O
inherent	O
structure	O
of	O
a	O
human	O
language	O
and	O
one	O
's	O
first	O
language	O
may	O
impact	O
the	O
lexical	B-General_Concept
density	I-General_Concept
of	O
the	O
individual	O
's	O
writing	O
and	O
speaking	O
style	O
.	O
</s>
<s>
The	O
lexical	B-General_Concept
density	I-General_Concept
impacts	O
the	O
readability	O
of	O
a	O
composition	O
and	O
the	O
ease	O
with	O
which	O
the	O
listener	O
or	O
reader	O
can	O
comprehend	O
a	O
communication	O
.	O
</s>
<s>
The	O
lexical	B-General_Concept
density	I-General_Concept
may	O
also	O
impact	O
the	O
memorability	O
and	O
retention	O
of	O
a	O
sentence	O
and	O
the	O
message	O
.	O
</s>
<s>
The	O
lexical	B-General_Concept
density	I-General_Concept
is	O
the	O
proportion	O
of	O
content	O
words	O
(	O
lexical	O
items	O
)	O
in	O
a	O
given	O
discourse	O
.	O
</s>
<s>
Lexical	B-General_Concept
density	I-General_Concept
is	O
one	O
of	O
the	O
methods	O
used	O
in	O
discourse	O
analysis	O
as	O
a	O
descriptive	O
parameter	O
which	O
varies	O
with	O
register	O
and	O
genre	O
.	O
</s>
<s>
There	O
are	O
many	O
proposed	O
methods	O
for	O
computing	O
the	O
lexical	B-General_Concept
density	I-General_Concept
of	O
any	O
composition	O
or	O
corpus	O
.	O
</s>
<s>
Lexical	B-General_Concept
density	I-General_Concept
may	O
be	O
determined	O
as	O
:	O
</s>
<s>
Ure	O
proposed	O
the	O
following	O
formula	O
in	O
1971	O
to	O
compute	O
the	O
lexical	B-General_Concept
density	I-General_Concept
of	O
a	O
sentence	O
:	O
</s>
<s>
Biber	O
terms	O
this	O
ratio	O
as	O
"	O
type-token	B-General_Concept
ratio	I-General_Concept
"	O
.	O
</s>
<s>
In	O
1985	O
,	O
Halliday	O
revised	O
the	O
denominator	O
of	O
the	O
Ure	O
formula	O
and	O
proposed	O
the	O
following	O
to	O
compute	O
the	O
lexical	B-General_Concept
density	I-General_Concept
of	O
a	O
sentence	O
:	O
</s>
<s>
In	O
some	O
formulations	O
,	O
the	O
Halliday	O
proposed	O
lexical	B-General_Concept
density	I-General_Concept
is	O
computed	O
as	O
a	O
simple	O
ratio	O
,	O
without	O
the	O
"	O
100	O
"	O
multiplier	O
.	O
</s>
<s>
Lexical	B-General_Concept
density	I-General_Concept
measurements	O
may	O
vary	O
for	O
the	O
same	O
composition	O
depending	O
on	O
how	O
a	O
"	O
lexical	O
item	O
"	O
is	O
defined	O
and	O
which	O
items	O
are	O
classified	O
as	O
lexical	O
or	O
as	O
a	O
grammatical	O
item	O
.	O
</s>
<s>
Any	O
adopted	O
methodology	O
when	O
consistently	O
applied	O
across	O
various	O
compositions	O
provides	O
the	O
lexical	B-General_Concept
density	I-General_Concept
of	O
those	O
compositions	O
.	O
</s>
<s>
Typically	O
,	O
the	O
lexical	B-General_Concept
density	I-General_Concept
of	O
a	O
written	O
composition	O
is	O
higher	O
than	O
a	O
spoken	O
composition	O
.	O
</s>
<s>
According	O
to	O
Ure	O
,	O
written	O
forms	O
of	O
human	O
communication	O
in	O
the	O
English	O
language	O
typically	O
have	O
lexical	B-General_Concept
densities	I-General_Concept
above	O
40%	O
,	O
while	O
spoken	O
forms	O
tend	O
to	O
have	O
lexical	B-General_Concept
densities	I-General_Concept
below	O
40%	O
.	O
</s>
<s>
In	O
a	O
survey	O
of	O
historical	O
texts	O
by	O
Michael	O
Stubbs	O
,	O
the	O
typical	O
lexical	B-General_Concept
density	I-General_Concept
of	O
fictional	O
literature	O
ranged	O
between	O
40%	O
and	O
54%	O
,	O
while	O
non-fiction	O
ranged	O
between	O
40%	O
and	O
65%	O
.	O
</s>
<s>
The	O
relation	O
and	O
intimacy	O
between	O
the	O
participants	O
of	O
a	O
particular	O
communication	O
impact	O
the	O
lexical	B-General_Concept
density	I-General_Concept
,	O
states	O
Ure	O
,	O
as	O
do	O
the	O
circumstances	O
prior	O
to	O
the	O
start	O
of	O
communication	O
for	O
the	O
same	O
speaker	O
or	O
writer	O
.	O
</s>
<s>
The	O
higher	O
lexical	B-General_Concept
density	I-General_Concept
of	O
written	O
forms	O
of	O
communication	O
,	O
she	O
proposed	O
,	O
is	O
primarily	O
because	O
written	O
forms	O
of	O
human	O
communication	O
involve	O
greater	O
preparation	O
,	O
reflection	O
and	O
revisions	O
.	O
</s>
<s>
Human	O
discussions	O
and	O
conversations	O
involving	O
or	O
anticipating	O
feedback	O
tend	O
to	O
be	O
sparser	O
and	O
have	O
lower	O
lexical	B-General_Concept
density	I-General_Concept
.	O
</s>
<s>
In	O
contrast	O
,	O
state	O
Stubbs	O
and	O
Biber	O
,	O
instructions	O
,	O
law	O
enforcement	O
orders	O
,	O
news	O
read	O
from	O
screen	O
prompts	O
within	O
the	O
allotted	O
time	O
,	O
and	O
literature	O
that	O
authors	O
expect	O
will	O
be	O
available	O
to	O
the	O
reader	O
for	O
re-reading	O
tend	O
to	O
maximize	O
lexical	B-General_Concept
density	I-General_Concept
.	O
</s>
<s>
In	O
surveys	O
of	O
lexical	B-General_Concept
density	I-General_Concept
of	O
spoken	O
and	O
written	O
materials	O
across	O
different	O
European	O
countries	O
and	O
age	O
groups	O
,	O
Johansson	O
and	O
Strömqvist	O
report	O
that	O
the	O
lexical	B-General_Concept
density	I-General_Concept
of	O
population	O
groups	O
were	O
similar	O
and	O
depended	O
on	O
the	O
morphological	O
structure	O
of	O
the	O
native	O
language	O
and	O
within	O
a	O
country	O
,	O
the	O
age	O
groups	O
sampled	O
.	O
</s>
<s>
The	O
lexical	B-General_Concept
density	I-General_Concept
was	O
highest	O
for	O
adults	O
,	O
while	O
the	O
variations	O
estimated	O
as	O
lexical	O
diversity	O
,	O
states	O
Johansson	O
,	O
were	O
higher	O
for	O
teenagers	O
for	O
the	O
same	O
age	O
group	O
(	O
13-year-olds	O
,	O
17-year-olds	O
)	O
.	O
</s>
