<s>
Shortest	B-General_Concept
seek	I-General_Concept
first	I-General_Concept
(	O
or	O
shortest	B-General_Concept
seek	I-General_Concept
time	I-General_Concept
first	I-General_Concept
)	O
is	O
a	O
secondary	B-Device
storage	I-Device
scheduling	B-General_Concept
algorithm	O
to	O
determine	O
the	O
motion	O
of	O
the	O
disk	B-Device
read-and-write	I-Device
head	I-Device
in	O
servicing	O
read	O
and	O
write	O
requests	O
.	O
</s>
<s>
The	O
shortest	B-General_Concept
seek	I-General_Concept
first	I-General_Concept
algorithm	O
determines	O
which	O
request	O
is	O
closest	O
to	O
the	O
current	O
position	O
of	O
the	O
head	O
,	O
and	O
then	O
services	O
that	O
request	O
next	O
.	O
</s>
<s>
The	O
shortest	B-General_Concept
seek	I-General_Concept
first	I-General_Concept
algorithm	O
has	O
the	O
direct	O
benefit	O
of	O
simplicity	O
and	O
is	O
clearly	O
advantageous	O
in	O
comparison	O
to	O
the	O
FIFO	O
method	O
,	O
in	O
that	O
overall	O
arm	O
movement	O
is	O
reduced	O
,	O
resulting	O
in	O
a	O
lower	O
average	O
response	O
time	O
.	O
</s>
<s>
However	O
,	O
since	O
the	O
buffer	O
is	O
always	O
getting	O
new	O
requests	O
,	O
these	O
can	O
skew	O
the	O
service	O
time	O
of	O
requests	O
that	O
may	O
be	O
farthest	O
away	O
from	O
the	O
disk	B-Device
head	I-Device
's	O
current	O
location	O
,	O
if	O
the	O
new	O
requests	O
are	O
all	O
close	O
to	O
the	O
current	O
location	O
;	O
in	O
fact	O
,	O
starvation	B-Operating_System
may	O
result	O
,	O
with	O
the	O
faraway	O
requests	O
never	O
being	O
able	O
to	O
make	O
progress	O
.	O
</s>
<s>
The	O
elevator	B-Algorithm
algorithm	I-Algorithm
is	O
one	O
alternative	O
for	O
reducing	O
arm	O
movement	O
and	O
response	O
time	O
,	O
and	O
ensuring	O
consistent	O
servicing	O
of	O
requests	O
.	O
</s>
