<s>
In	O
the	O
field	O
of	O
human	O
–	O
computer	O
interaction	O
,	O
a	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
experiment	I-General_Concept
is	O
a	O
research	O
experiment	O
in	O
which	O
subjects	O
interact	O
with	O
a	O
computer	O
system	O
that	O
subjects	O
believe	O
to	O
be	O
autonomous	O
,	O
but	O
which	O
is	O
actually	O
being	O
operated	O
or	O
partially	O
operated	O
by	O
an	O
unseen	O
human	O
being	O
.	O
</s>
<s>
The	O
phrase	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
(	O
originally	O
OZ	O
Paradigm	O
)	O
has	O
come	O
into	O
common	O
usage	O
in	O
the	O
fields	O
of	O
experimental	O
psychology	O
,	O
human	O
factors	O
,	O
ergonomics	O
,	O
linguistics	O
,	O
and	O
usability	O
engineering	O
to	O
describe	O
a	O
testing	O
or	O
iterative	O
design	O
methodology	O
wherein	O
an	O
experimenter	O
(	O
the	O
“	O
wizard	O
”	O
)	O
,	O
in	O
a	O
laboratory	O
setting	O
,	O
simulates	O
the	O
behavior	O
of	O
a	O
theoretical	O
intelligent	O
computer	O
application	O
(	O
often	O
by	O
going	O
into	O
another	O
room	O
and	O
intercepting	O
all	O
communications	O
between	O
participant	O
and	O
system	O
)	O
.	O
</s>
<s>
In	O
testing	O
situations	O
,	O
the	O
goal	O
of	O
such	O
experiments	O
may	O
be	O
to	O
observe	O
the	O
use	O
and	O
effectiveness	O
of	O
a	O
proposed	O
user	B-Application
interface	I-Application
by	O
the	O
test	O
participants	O
,	O
rather	O
than	O
to	O
measure	O
the	O
quality	O
of	O
an	O
entire	O
system	O
.	O
</s>
<s>
The	O
name	O
of	O
the	O
experiment	O
comes	O
from	O
The	O
Wonderful	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
story	O
,	O
in	O
which	O
an	O
ordinary	O
man	O
hides	O
behind	O
a	O
curtain	O
and	O
pretends	O
,	O
through	O
the	O
use	O
of	O
"	O
amplifying	O
"	O
technology	O
,	O
to	O
be	O
a	O
powerful	O
wizard	O
.	O
</s>
<s>
John	O
F	O
.	O
(	O
“	O
Jeff	O
”	O
)	O
Kelley	O
coined	O
the	O
phrases	O
“	O
Wizard	B-General_Concept
of	I-General_Concept
OZ	I-General_Concept
”	O
and	O
“	O
OZ	O
Paradigm	O
”	O
for	O
this	O
purpose	O
circa	O
1980	O
to	O
describe	O
the	O
method	O
he	O
developed	O
during	O
his	O
dissertation	O
work	O
at	O
Johns	O
Hopkins	O
University	O
.	O
</s>
<s>
Dr.	O
Ford	O
's	O
recollection	O
was	O
that	O
Dr.	O
Kelley	O
did	O
in	O
fact	O
coin	O
the	O
phrase	O
"	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
Paradigm	O
"	O
but	O
that	O
the	O
technique	O
had	O
been	O
employed	O
in	O
at	O
least	O
two	O
separate	O
studies	O
before	O
Dr.	O
Kelley	O
had	O
started	O
conducting	O
studies	O
at	O
the	O
Johns	O
Hopkins	O
Telecommunications	O
Lab	O
.	O
</s>
<s>
Again	O
,	O
the	O
name	O
"	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
"	O
had	O
not	O
yet	O
been	O
applied	O
to	O
this	O
technique	O
.	O
</s>
<s>
The	O
first	O
appearance	O
of	O
the	O
"	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
"	O
name	O
in	O
print	O
was	O
in	O
Jeff	O
Kelley	O
's	O
thesis	O
(	O
Kelley	O
,	O
1983a	O
,	O
1983b	O
,	O
1984a	O
)	O
.	O
</s>
<s>
There	O
is	O
also	O
a	O
passing	O
reference	O
to	O
planned	O
use	O
of	O
the	O
"	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
experiments	O
"	O
in	O
a	O
by	O
Ford	O
and	O
Smith	O
.	O
</s>
<s>
One	O
fact	O
,	O
presented	O
in	O
Kelley	O
's	O
dissertation	O
,	O
about	O
the	O
etymology	O
of	O
the	O
term	O
in	O
this	O
context	O
:	O
Dr.	O
Kelley	O
did	O
originally	O
have	O
a	O
definition	O
for	O
the	O
“	O
OZ	O
”	O
acronym	O
(	O
aside	O
from	O
the	O
obvious	O
parallels	O
with	O
the	O
1900	O
book	O
The	O
Wonderful	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
by	O
L	O
Frank	O
Baum	O
)	O
.	O
</s>
<s>
Similar	O
experimental	O
setups	O
had	O
occasionally	O
been	O
used	O
earlier	O
,	O
but	O
without	O
the	O
"	O
Wizard	B-General_Concept
of	I-General_Concept
Oz	I-General_Concept
"	O
name	O
.	O
</s>
<s>
Design	O
researcher	O
Nigel	O
Cross	O
conducted	O
studies	O
in	O
the	O
1960s	O
with	O
"	O
simulated	O
"	O
computer-aided	B-Application
design	I-Application
systems	O
where	O
the	O
purported	O
simulator	O
was	O
actually	O
a	O
human	O
operator	O
,	O
using	O
text	O
and	O
graphical	O
communication	O
via	O
CCTV	O
.	O
</s>
<s>
The	O
Wizard	B-General_Concept
of	I-General_Concept
OZ	I-General_Concept
method	O
is	O
very	O
powerful	O
.	O
</s>
<s>
The	O
processing	O
model	O
was	O
a	O
two-pass	O
keyword/key	O
-phrase	O
matching	O
approach	O
,	O
based	O
loosely	O
on	O
the	O
algorithms	O
employed	O
in	O
Weizenbaum	O
's	O
famous	O
Eliza	B-Application
program	O
.	O
</s>
<s>
In	O
the	O
23	O
years	O
that	O
followed	O
initial	O
publication	O
,	O
the	O
OZ	O
method	O
has	O
been	O
employed	O
in	O
a	O
wide	O
variety	O
of	O
settings	O
,	O
notably	O
in	O
the	O
prototyping	O
and	O
usability	O
testing	O
of	O
proposed	O
user	B-Application
interface	I-Application
designs	O
in	O
advance	O
of	O
having	O
actual	O
application	O
software	O
in	O
place	O
.	O
</s>
