<s>
An	O
error-tolerant	B-General_Concept
design	I-General_Concept
(	O
or	O
human-error-tolerant	O
design	O
)	O
is	O
one	O
that	O
does	O
not	O
unduly	O
penalize	O
user	O
or	O
human	O
errors	O
.	O
</s>
<s>
It	O
is	O
the	O
human	O
equivalent	O
of	O
fault	B-General_Concept
tolerant	I-General_Concept
design	I-General_Concept
that	O
allows	O
equipment	O
to	O
continue	O
functioning	O
in	O
the	O
presence	O
of	O
hardware	O
faults	O
,	O
such	O
as	O
a	O
"	O
limp-in	O
"	O
mode	O
for	O
an	O
automobile	O
electronics	O
unit	O
that	O
would	O
be	O
employed	O
if	O
something	O
like	O
the	O
oxygen	O
sensor	O
failed	O
.	O
</s>
<s>
Use	O
of	O
forcing	O
functions	O
or	O
behavior-shaping	O
constraints	O
is	O
one	O
technique	O
in	O
error-tolerant	B-General_Concept
design	I-General_Concept
.	O
</s>
<s>
An	O
example	O
is	O
the	O
interlock	B-General_Concept
or	O
lockout	O
of	O
reverse	O
in	O
the	O
transmission	O
of	O
a	O
moving	O
car	O
.	O
</s>
<s>
This	O
prevents	O
errors	O
,	O
and	O
prevention	O
of	O
errors	O
is	O
the	O
most	O
effective	O
technique	O
in	O
error-tolerant	B-General_Concept
design	I-General_Concept
.	O
</s>
<s>
The	O
next	O
most	O
effective	O
technique	O
in	O
error-tolerant	B-General_Concept
design	I-General_Concept
is	O
the	O
mitigation	O
or	O
limitation	O
of	O
the	O
effects	O
of	O
errors	O
after	O
they	O
have	O
been	O
made	O
.	O
</s>
<s>
An	O
example	O
is	O
a	O
checking	O
or	O
confirmation	O
function	O
such	O
as	O
an	O
"	O
Are	O
you	O
sure	O
"	O
dialog	O
box	O
with	O
the	O
harmless	O
option	O
preselected	O
in	O
computer	O
software	O
for	O
an	O
action	O
that	O
could	O
have	O
severe	O
consequences	O
if	O
made	O
in	O
error	O
,	O
such	O
as	O
deleting	O
or	O
overwriting	O
files	O
(	O
although	O
the	O
consequence	O
of	O
inadvertent	O
file	O
deletion	O
has	O
been	O
reduced	O
from	O
the	O
DOS	B-Device
days	O
by	O
a	O
concept	O
like	O
the	O
trash	B-Application
can	I-Application
in	O
Mac	B-Application
OS	I-Application
,	O
which	O
has	O
been	O
introduced	O
in	O
most	O
GUI	B-Application
interfaces	O
)	O
.	O
</s>
<s>
Another	O
example	O
is	O
Google	B-Application
's	I-Application
use	O
of	O
spell	B-Application
checking	I-Application
on	O
searches	O
performed	O
through	O
their	O
search	O
engine	O
.	O
</s>
<s>
The	O
spell	B-Application
checking	I-Application
minimises	O
the	O
problems	O
caused	O
by	O
incorrect	O
spelling	O
by	O
not	O
only	O
highlighting	O
the	O
error	O
to	O
the	O
user	O
,	O
but	O
by	O
also	O
providing	O
a	O
link	O
to	O
search	O
using	O
the	O
correct	O
spelling	O
instead	O
.	O
</s>
<s>
Searches	O
like	O
this	O
are	O
commonly	O
performed	O
using	O
a	O
combination	O
of	O
edit	O
distance	O
,	O
soundex	B-Algorithm
,	O
and	O
metaphone	B-Algorithm
calculations	O
.	O
</s>
