00100	EVALUATION 
00200	
00300		The primary aim in constructing this model  was  to  explore,
00400	clarify, develop, test and improve a theory having explanatory value.
00500	To  satisfy  this  aim,  the  model  must  meet  norms  of   internal
00600	consistency  (systemicity)  and norms of external correspondence with
00700	observation (testability). A secondary aim  would  involve  pragmatic
00800	norms  of  application.  These aims are not unrelated but our primary
00900	one is more fundamental since useful applications require some degree
01000	of consistency and observational correspondence.
01100		As  emphasized  in  Chapter  2, a  model  in  the  form of an
01200	algorithm consists of a structure of functions  or  procedures  whose
01300	inner  workings  are  sufficient  to  reproduce  the outward symbolic
01400	behavior under consideration. The theory embodied  in  the  model  is
01500	revealed  in  the set of statements which illuminate  the connections
01600	betweeen input and output by  describing  how  the  structure  reacts
01700	under various circumstances.
01800		What  constitutes a satisfactory explanation has been treated
01900	in 2.1.  The "fit" or correspondence with phenomena as  indicated  by
02000	measurements and empirical tests indicate the degree of faithfulness
02100	of the reproduction as described in Chapter 6.
02200		Decision procedures for a consensus acceptability of a  model
02300	sometimes  depend  not  so  much  on  truth,  an elusive state, as on
02400	whether a majority of the  relevant  expert  community  believes  the
02500	theory  or  model to approximate truth to some unknown and unknowable
02600	degree and  to  be  better  than  available  plausible  alternatives.
02700	Validation  is  ultimately  a  private  experience of the individual.
02800	Empirical truth or falsity cannot be proven with certainty but  their
02900	presence  can  be  assayed  by  some  sort  of critical assesment and
03000	deliberation. We can forgive models for being only  nearly  true.   A
03100	theory or model may bring cognitive or pragmatic comfort, not because
03200	it is  TRUE  but  because  it  represents  an  improvement  over  its
03300	contending rivals.
03400		Cognitive comfort is a  type  of  intellectual  satisfaction.
03500	Pragmatic  comfort  accrues from applications to problems in order to
03600	make things work the way humans want  them  to  work  efficiently  in
03700	practical  contexts  of  technological  action. For the pragmatist, a
03800	model is a means to an end;  for  the  theoretician,  an  explanatory
03900	model  is  an end in itself. It is hoped that this paranoid model can
04000	contribute to understanding one of the mysteries  of  human  conduct,
04100	the  paranoid mode. There remains the enigma of the paranoid "streak"
04200	which renders whole nations  susceptible  to  idelogical  convictions
04300	regarding Elsewhereans as malevolent oppressors.
04400		It is a truism  of  methodology  texbooks  that  an  infinite
04500	number  of  theories  or  models  can  account  for  the same data of
04600	observation.    Without   questioning   whether   "infinite"    means
04700	indefinitely  large  or  just  more than one, we must allow for rival
04800	explanations. For a rival to be a live and tenable option, it  should
04900	be  truly alternative (i.e., not just a version saying the same thing
05000	in a different way), have an appreciable prior  probability,  and  be
05100	testable.
05200		Although I  hold  that  faithful  reproduction,  fidelity  as
05300	measured  by indistinguishability, is a proper and major test for the
05400	adequacy of simulation models, it would be a bonus if our model could
05500	satisfy  the  function  of  making  possible  new  knowledge  through
05600	prediction. The term "prediction" has a spectrum of meanings  ranging
05700	from    forecasts,    to   prognoses   to   prophecies   to   precise
05800	point-predictions in time. To predict is to announce a  fact  without
05900	prior  knowledge  of  it.  However one needs knowledge of the kind of
06000	fact expected, the conditions which produce it and the  circumstances
06100	under   which   it   will  occur.   Accurate  long-range  predictions
06200	characterize the ideal of celestial mechanics.  But even astronomers,
06300	with  the  advantage  of  isolated and repetitive systems, have their
06400	troubles; Halley's comet in the 18th century arrived four days  later
06500	than  predicted. With all our advanced knowledge of the 20th century,
06600	the pesky comet nevertheless arrived eight days later than predicted.
06700		Long-range  predictions  of  individual  human  behavior  are
06800	difficult because (1) sufficient knowledge of initial conditions  may
06900	require  that  we  know the whole past history of a person- something
07000	not yet achieved, (2) individuals do not  remain  isolated  over  the
07100	time  stretch of the prediction; they interact with other individuals
07200	of an unknown  nature  (3)  life  is  a  fortuitous  flux  of  chance
07300	intersections  of  independent  causal  chains.   In  one  sense  our
07400	paranoid model makes moment-to-moment  predictions  and  asserts  new
07500	counterfactuals  about  behavior in a psychiatric interview. That is,
07600	if an interviewer  says  X  under  conditions  Y,  then  the  model's
07700	response will be characterized by z1...zn.  Counterfactual prediction
07800	means that on the basis of observed behavior we are  willing,with  an
07900	inductive  risk,  to  assume  the  presence  of  unobserved  behavior
08000	potentials in the model's repertoire of capabilities.
08100		Predicting  new  kinds  of  events  or properties, instead of
08200	kinds we are already familiar with, would represent a genuine  bonus,
08300	indicating  the  model is more than ad hoc and has excess content. It
08400	would give both clinicians and investigators something to  look  for.
08500	This  novelty  could  arise  in  two  ways.    First, the model might
08600	demonstrate a property  of  the  paranoid  mode  hitherto  unobserved
08700	clinically.      In  principle  this could come about because the I/O
08800	behavior of  the  model  is  a  consequence  of  a  large  number  of
08900	interacting  hypotheses  and  assumptions chosen initially to explain
09000	frequently observed phenomena.    When the elements of such a complex
09100	conjunction  interact  with  highly  variable  inputs  they  generate
09200	consequences in addition to those  they  were  designed  to  explain.
09300	Whether  any  of these consequences are significant or characteristic
09400	of the paranoid mode remains a subject for future study.
09500		It  is  also  possible that a new property of paranoia may be
09600	discovered in the clinical  interview,  although  perhaps  everything
09700	that  can  be  said about paranoid dialogues has been said.  If a new
09800	property were found, a search  for  it  might  be  conducted  in  the
09900	model's  behavior. if successful, this again would add to the model's
10000	acceptability.
10100		A  second novelty might arise in the behavior of the model in
10200	some new situation.   Since it is designed to simulate  communicative
10300	behavior in an interview situation, the `new' circumstance would have
10400	to involve some new type of linguistic interaction which the model is
10500	capable  of  responding  to. From its behavior one might then predict
10600	how paranoid patients would behave under similar circumstances.   The
10700	requisite  empirical  tests  and  measures  would  show the degree of
10800	correspondence between patient and model behaviors.
10900		This  possibility  is  of importance in considering therapies
11000	for patients tangled in the quandaries of the paranoid mode.    Since
11100	the  model  operates  at  a  symbol  processing  level  using natural
11200	language, it is at this level at which linguistic and semantic skills
11300	of  clinicians  can be applied. Language-based or semantic techniques
11400	do not seem very effective in the psychoses but they  are  useful  in
11500	states  of  lesser severity. A wide range of new semantic techniques,
11600	including extremes,  could  be  tried  first  on  the  model  without
11700	subjecting patients to blind experimentation.
11800		While our group has used the model to explore a theory and to
11900	study psychiatric judgements, its potential use as a training  device
12000	has  not  escaped  our  attention.   Medical students and psychiatric
12100	residents need "disposable patients" to practice on without jeopardy.
12200	A  version of the paranoid model can display the changes in its inner
12300	states  during  an  interview.    Whether   the   optimal   goal   of
12400	interviewing  (gathering  relevant  information without upsetting the
12500	patient), has been achieved, thus  can  be  estimated.   A  beginning
12600	interviewer  can  practice  in  private or with a supervisor present.
12700	Many interviewers have reported that the model has a definite  effect
12800	on  them.   The  student  can  get the feel of the paranoid mode long
12900	before he interviews an  actual  patient.    The  effect  of  various
13000	interviewing styles might be studied and compared.
13100	
13200		It should be clear by now that this simulation  of  paranoia,
13300	while  circumscribed in what it attempts to explain, covers a variety
13400	of facts. The explanation is local and restricted in that it accounts
13500	for only one type of symbol-processing mode.  Past attempts at grand-
13600	scale  explanations  of  all  mental  processes  in all contexts have
13700	failed.   We need to build one circumscribed  and  tested  theory  or
13800	model  at  a time so that the field can gradually move forward a step
13900	at a time, each step gaining consensus  before  attempting  the next.