CHAPTER 3-2             

             EXPERTS, EXPERT SYSTEMS, AND LIBRARIES
 
     On what date this year would it be best to plant the field 
at the northeast corner of the old Reith farm in Champaign 
County?  How should you deal with a set of brand-new boots and 
tender feet when you find yourself forced to take a long march in 
them tomorrow?  What are the problems to be overcome in disposing 
of nuclear waste, and what is the best way to overcome them?  How 
much welfare services do immigrants to the U. S. use, and how 
much taxes do they pay, on average?  
     Knowledge exists that can help you answer these questions.  
How you may acquire such knowledge is the subject of this 
chapter. 
     Look first for knowledge where the knowledge may already 
exist -- in experts, computerized "expert systems" that codify 
the knowledge of experts, and libraries whose books and 
periodicals may contain the writings by experts and scholars of 
the subject.  This chapter is about how to take advantage of 
these sources of knowledge. 
     The knowledge referred to in this chapter includes both 
applied knowhow -- such as techniques that will prevent tender 
feet from getting sore on a long march, and also abstract 
knowledge -- such as understanding why new skin grows at the rate 
it does on the feet and on the face.  Tacit knowledge, such as 
how to patch up feet that are sore from a long march, must be 
acquired by experience. 

                             EXPERTS
     Obviously it makes sense to start your search for an answer 
to a particular question by seeking help from people who 
understand where the relevant knowledge may be located.  Experts 
serve two helpful functions, as subject-matter experts and as 
librarians.  They can apply knowledge which they possess, as when 
a refrigerator repair-person fixes your machine or a lawyer gets 
a patent for your invention.  Experts also can serve as your 
guides in the realm of abstract knowledge.  
      A subject-matter expert can summarize for you the existing 
knowledge relevant to a routine question, making it unnecessary 
for you to venture into the library at all.  For example, a 
competent lawyer can tell you how the law of copyright applies to 
reproducing an advertisement in a book.  (If the point is very 
tricky, however, you need a truly first-class lawyer.  Or you 
might learn how to do legal research and study the point 
yourself.)   Another example:  if you seek a mechanism to help 
your bank predict whether a borrower will repay a loan, a scholar 
in finance may be able to quickly provide you an appropriate 
formula and a copy of the article which describes it.  
     On some questions, however, the "experts" are useless or 
worse.  For example, for decades the consensus of the "energy 
experts" has predicted that the price of energy will go up, 
against all the evidence of history.  And for decades their 
forecasts have been terribly wrong, costing Americans hundreds of 
billions of dollars.  On this matter you would have done better 
to venture into the library yourself and study the problem down 
to its roots, rather than consulting the supposed "experts", 
though this obviously would not have been easy to do.  
     People frequently claim to possess knowledge on subjects 
about which they are ignorant.  And they are often willing to 
charge you high prices for that supposed knowledge.  As an 
industrial folk-saying has it, an expert is a guy from out of 
town.  Your problem is to determine if a person does indeed 
possess valid knowledge.   The problem is much the same with 
respect to both experts and non-experts except that the knowledge 
which supposed experts offer usually is relatively arcane, and 
therefore it is harder for you to test for quality.  The 
knowledge that a dentist applies to your mouth, for example, is 
especially hard to rate because it is almost never put to a 
public examination; even asking another dentist is seldom a 
satisfactory test. 
     Here are some guidelines to help you assess whether another 
person possesses knowledge that will be useful to you: 
     1.  The more local and specific the subject, the more likely 
the answer will valid.  If you want to know whether a given field 
on a given farm is dry enough to plant as of today, the farmer 
who cultivates that farm is likely to have very reliable 
knowledge on that subject.  He or she has direct sense knowledge 
of the situation through her/his eyes, and probably has had 
specific experience with that field for some years past, plus 
relevant general knowledge of when to plant.  
     Indeed, even if the farmer is not an accredited expert on 
agronomy, she/he is likely to have better knowledge about when to 
plant that specific field than is an accredited expert in an 
office many miles away.  The importance of specific knowledge of 
this kind held by people working on a particular farm or in a 
particular factory or in a particular retail establishment is one 
of the main reasons why central planning such as practiced in 
Soviet communism up until at least the date of writing in 1990 
cannot in principle be as efficient as a decentralized market 
system.  (More about this in Chapter 6-4.  This is another 
example of how the same principles of thinking show up in 
different contexts.) 
     Our politic often errs by not distinguishing local from 
distant knowledge.  If you ask Susan whether co-worker immigrant 
Sam is a hard worker who pays more in taxes than the cost of the 
welfare services Sam's family uses, Susan's knowledge is likely 
to be very reliable.  But if you ask Susan whether immigrants 
from Sam's country generally are hard workers and not welfare 
abusers, her knowledge is likely to be worse than useless.  Hence 
polls regularly show the inconsistent results that Americans say 
positive things about the immigrants they know, and negative 
things about immigrants in general.  The same is true of poll 
questions about whether their own neighborhoods are overcrowded, 
compared to questions about  whether the country and planet as 
wholes are overcrowded.  Yet reporters and politicians give 
weight to public opinion that immigration should be reduced 
because of welfare abuse, and that population growth should be 
reduced because of overcrowding, in violation of this principle 
that knowledge about events at large is likely to be less 
reliable than knowledge of the situation close at hand. 
     The less local and specific the knowledge, the more 
necessary are the specialized scientific techniques discussed in 
the next chapter.  
     2.  The more formal education the person has had with 
respect to a subject, the more knowledge the person is likely to 
possess.  This principle is obvious.  The strength of experts' 
education is in areas of knowledge that require specialized 
techniques and training.  (Of course dowsers claim that their 
extensive training with the specialized techniques holding a 
forked stick make them experts at finding water, but not all 
specialized techniques and training are proof of valid 
knowledge.)  
     Furthermore, as noted in point 1 above, formal education is 
not always enough to offset lack of local knowledge or lack of 
experience.  Once when I was in the Navy and had just joined a 
Marine battalion, I needed information about how to prepare for a 
long hike in brand-new boots.  I found that enlisted Chief Petty 
Officer medical corpsmen (the equivalent of Master Sergeants) 
knew more about practical remedies such as painting the tender 
areas of the foot with protective tincture of benzoine, and 
standing in a pan of water to wet the boots before departing, 
than did physicians who had had much more formal education but 
less experience with this particular problem. 
     Education and impressive credentials are not solid proof of 
expertise, as a history of unfounded expert assessments, The 
Experts Speak (Cerf and Navasky, 1984) shows in hilarious detail.  
Supposedly well-informed persons holding their country's highest 
political posts often make ludicrously wrong predictions.  For 
example, Benjamin Disraeli, then Chancellor of the Exchequer and 
later Prime Minister of Great Britain, asserted that building the 
Suez Canal was a "most futile attempt and totally impossible to 
be carried out" (p. 219).  And the most authoritative 
publications and specialists have told us that such innovations 
as railroad trains, automobiles, airplanes, submarines, electric 
light, the phonograph, the telegraph, and the telephone were 
technologically impossible or would never amount to anything even 
if they could be created.  Perhaps most amazingly, the world's 
best scientists often are utterly wrong -- and with confidence! -
- even about their very own subjects.  
     The subject of nuclear power is instructive because it is of 
current interest.  These were the assessments of three of the 
greatest physicists of our time or any other.  "There is no 
likelihood man can ever tap the power of the atom", said Robert 
Millikan (Cerf and Navasky, p. 214).  "There is not the slightest 
indication that [nuclear energy] will ever be obtainable", said 
Albert Einstein (p. 215).  And "The energy produced by the atom 
is a very poor kind of thing.  Anyone who expects a source of 
power from the transformation of these atoms is talking 
moonshine", said Ernest Rutherford, himself one of the great 
pioneers in the field (p. 215). 
     Even The Experts Speak, the compendium of experts' nonsense 
from which I just quoted sometimes gets it completely wrong, 
labeling sound judgment as nonsense.  For example, it quotes as 
nonsense the inventor of the hydrogen bomb, Edward Teller, as 
saying "What do you think you get more radiation from, leaning up 
against an atomic reactor or your wife?...[Y]ou get just a bit 
more from [the reactor] than from your wife" (p. 217).  Teller is 
unquestionable correct.  He went on to joke that perhaps this 
meant only that one should not sleep with more than one other 
person at a time.  Also quoted is physicist, Dixy Lee Ray, ex-
Governor of Washington, and former Chairman of the Atomic Energy 
Commission, saying "A nuclear power plant is infinitely safer 
than eating, because 300 people choke to death on food every year 
[in the United States]" (p. 216).  And she is quite right, 
because nuclear power has caused zero deaths in the U. S., unlike 
every other energy source, and even the Soviet experience does 
not tilt the balance the other way.  (Do I hear you saying that I 
have it wrong?  Maybe this makes the point.) 
     In my own trade of economics, the profession passed from a 
majority of the most respected scholars approving Keynesian 
theory and policies in the 1950's and 1960's, to the vast 
majority approving quite the opposite sort of theory and policies 
by 1989.  So much for trusting in the experts. 
     Whether the government should license experts in a given 
field is always an interesting question.  In some cases licensing 
obviously is protection for the incomes of the practitioners; 
requiring six months or a year of training in such subjects as 
electricity and blood chemistry does not improve a barber's 
skill, and few people would have trouble sorting out the bad 
barbers from the good barbers without a license on the wall.  And 
if there were no legal requirements to become a physician, 
private agencies rating physicians might (or might not) soon sell 
information providing better protection than do the legal 
requirements.  Government licensing of such professions as public 
relations can appeal only to the most naive members of the public 
-- plus, of course, the practitioners who would be protected from 
competition.  But the fact that an electrician is certified by 
the state as competent might indicate a somewhat better chance 
that your job will be done right than if it is done by an 
uncertified person. 
     It is also important to recognize when a distinguished 
expert is opining about matters which are outside the person's 
field of knowledge.  In such case, you should pay no more 
attention than you would to any other layperson.  Einstein, 
Bertrand Russell, and Andrei Sakharov are examples of great minds 
in science who have been remarkably naive -- indeed, downright 
ignorant -- about economic systems; yet all have written in 
praise of socialism.  Experts in one field are all too often 
given forums for their opinions in other fields, and too often 
they accept the lure instead of steadfastly keeping their public 
pronouncements to what they know about.       
     3.  The more experience the person has had, the more 
reliable the knowledge.  If Susan has worked with immigrant Sam 
for ten years, her knowledge of his work discipline is likely to 
be greater than if she worked a week with him.  But in some 
situations, experience may not be enough to offset lack of 
education.  As it is truly said of some people: he has had twenty 
years of experience -- one years' worth, twenty times.  And the 
long experience may lead to the belief that a person must know a 
lot about the situation, even if he doesn't, because otherwise he 
would be stupid and we both know that he is not stupid, right?       
4.  The more immediately testable the knowledge, the more 
reliable the expert is likely to be.  A refrigerator repairer is 
likely to be more reliable when she says that she can fix the 
machine than is a head shrinker who says that he can repair your 
schizophrenia, or an economist who claims to know when to 
increase the nation's money supply.  One reason that immediate 
testability is linked to knowledge is that in such cases the 
expert gets lots of chances to check her/his ideas against the 
reality of what works and what does not -- that is, lots of 
`feedback' that should improve his/her knowledge. 
     5.  The more uniform the results of a procedure, the more 
reliable the supposed expert.  Refrigerators respond more 
uniformly to treatment than do schizophrenics or economies, for 
reasons that are fairly obvious but that would be hard to state 
briefly.      
     6.  The larger the body of tested scientific knowledge on a 
subject, and the more evidence that has accumulated, the more 
reliable the experts are likely to be.  There have been many more 
experiments with drugs to combat high blood pressure than with 
drugs to increase creativity, and therefore people who prescribe 
the former are more deserving of credence than those who 
prescribe the latter.  And a physician who says that aspirin will 
not cause delayed side effects is more to be believed than a 
physician who says that the newest drug for depression will cause 
no side effects, because aspirin has been used so widely for so 
many years. 
     7.  The absence of scientific proof that a procedure works, 
and the presence of scientific evidence that the procedure does 
not work, suggest that no one should be considered an expert in 
the practice of that procedure.  For half a century studies have 
shown that the stockmarket "experts" do not forecast which way 
the market is going in the short run any better than a flipped 
coin does.  But great is the human desire to feel that the world 
is not beyond our control, and great is our belief that there 
just might be magic this time.  People therefore continue 
unabatedly to pay large sums of money for market forecasts in 
newspapers and newsletters, and by stockbrokers. J. Scott 
Armstrong calls this the "seersucker principle":  "No matter how 
much evidence exists that seers do not exist [in a given field], 
suckers will pay for the existence of seers" (1979, p. 1)  (More 
about this in Chapter 8-0 on investment, and in Chapters 4-5 and 
4-6 on clarity and error). 
     It is quite amazing that scientific testing is not conducted 
even when it is easy to do.  Dentists obviously did not test the 
old method of up-and-down brushing before they "expertly" 
prescribed it to everyone in the nation, or they would not now be 
prescribing side-to-side brushing.  Whether they have yet tested 
the latter I do not know.  But which patient would question their 
expertness on this subject?  Much the same was true of the 
exercises prescribed to millions of back sufferers until a few 
years ago. 
     8.  The greater the benefit to the person from simply 
providing an opinion -- distinguished from producing results, as 
in the case of refrigerator repair -- the greater the chance that 
you will pay for worthless knowledge.  A racetrack tout has an 
obvious stake in your believing that the tout has some inside 
knowledge about which horse will win.  So does a stockbroker; if 
you believe the stockbroker's recommendations, you will buy and 
sell more stock from her and provide her more profit in 
commissions.  Consultants who claim to be able to improve jury 
selection have an obvious stake in parties to legal disputes 
believing that the consultants can pick better than chance, in 
spite of solid evidence that they have no more skill than does a 
dart thrown at random [***reference from Rita].  And 
psychologists and psychiatrists who are "professional clinicians 
do not in fact make more accurate clinical judgments than 
laypersons" when predicting violent behavior or determining who 
is faking mental illness; hence they seem to be of little 
assistance in court trials (Faust and Ziskin, 1988).  It is not 
surprising that psychoanalysts did not welcome and proclaim the 
tests that showed an absence of proven improvement from their 
expensive treatments. 
     You must also worry about the expert's self-interest or even 
knowledge itself affecting the content of the information you 
receive.  Scientists who study nuclear fusion obviously desire  
U. S. senators and congressional representatives to believe that 
fusion has a bright future if research in it is well-supported.  
But there is a mechanism operating in the opposite direction in 
some circumstances; experts often are overly pessimistic about 
future discoveries in their fields.  Apparently this happens 
because they focus on the sub-fields in which they work, which 
have already been opened up (by definition), and they focus away 
from the possibility of wholly-new sub-fields outside their own.       
     You can improve your chances of getting valuable knowledge 
from experts if you check the results of those you are 
considering employing.  In some fields such as economic 
forecasting, those people identified as experts do no better than 
chance at forecasting short-run ups and downs, so you do not even 
need to check out individuals.  (Of course some individuals will 
seem to have successful track records, but this is almost surely 
due to chance, just as someone in a crowd of ten thousand people 
each flipping ten coins will probably observe ten heads.  (For 
more about this, see Chapter 1-4 on uncertainty). 
     Journalists seldom check the records of experts.  Instead, 
they usually decide whom to consult on the basis of fame and 
organizational attachment.  Just as a celebrity may be be said to 
be a person well-known for being well-known, an expert is a 
person whom others think is an expert.  For example, the best-
known prophets of gloom-and-doom with respect to the world's food 
and natural resources have been wrong again and again.  Yet the 
same people who have been so consistently wrong during the last 
two decades of concern about these matters continue to be the 
most-consulted of all.  Their abysmal forecasting records seem 
never to be held against them. 
     Young people often have trouble accepting how wrong experts 
can be, perhaps because most of the information that children 
receive is specific and well-founded:  If you don't wear a hat 
your ears will be cold; turn your hips when you hit the ball.  
Children extend this trust to matters about which knowledge is 
much less well-founded, and the trust is often fostered by the 
prestige of persons they hear from -- honored professors, 
respected journalists, and so on.  
     Indeed, it is uncomfortable for us adults, too, to think 
that some important part of the world around us is unknown and 
even unknowable. We like to feel that we can master our 
environment, and it comes very hard to be told that we cannot.     
Though this section focuses on experts, the topic blends into the 
entire subjects of knowledge and of sound thinking.  Therefore, 
many other chapters in the book throw light on experts and 
expertise, and how to think about them. 
     How to work with experts so as to effectively transfer their 
knowledge to you deserves some attention, but there is no space 
for it here. 
                         EXPERT SYSTEMS
     An "expert system" is part of the recently-developing field  
known as "artificial intelligence"; such a system is a synthetic 
expert.  The people who create the program mine and systematize 
the knowledge of several living breathing experts into a computer 
program which may then be consulted by a user.  For example, the 
MYCIN program combines the knowledge of physicians skilled in 
diagnosing and treating meningitis and bacterial infections of 
the blood into a computer file which other physicians can then 
consult.  
     The computer has a wider array of information stored in it 
than does a single ordinary physician's memory, because the 
program creators drew upon the knowledge of several top-notch 
experts.  This means that exotic diseases which the ordinary 
physician would never see in a lifetime are catalogued in the 
computer, along with a wide range of symptoms that might only 
occasionally be seen.  The computer also has the advantage that 
it is never forgetful or fatigued.  In operation, the computer 
asks the user a series of questions, each question depending upon 
the answers previously given, in a sequence resembling the way 
that a physician ordinarily thinks when making a diagnosis.  
     A hypothetical automobile-repair example is easier for the 
lay person to follow than a medical example.  The computer first 
asks you to classify your problem into either 1) car won't start, 
or 2) some other problem.  If you respond with "1", the computer 
then asks you if 1) headlights are dim, 2) the fuel filter is 
clogged, or 3) the battery cables are loose or corroded.  The 
computer also asks for information about the starter:  1) no 
cranking? 2) slow cranking? 3) normal cranking? 4) grinding noise 
from starter?  Depending on which pair of answers you give, the 
computer asks you further questions, until there is enough 
information to recommend what to do. (adapted from Harmon and 
King, 1985 pp. 110-111). 
     Expert systems are still in their youth.  Other successful 
examples include a program to aid decisions made in oil drilling, 
another for geologists' use in prospecting for ore deposits, and 
a system to make diagnoses in locomotive repair. 
     An expert system is very specific.  It gives you a diagnosis 
and treatment for a particular person's illness, or a particular 
car's problem.  Knowledge in libraries tends to be more abstract.  
Consider, for example, a formula that help banks predict who will 
default on loans.  The formula is a general tool that you apply 
to a specific case by inserting the particular characteristics of 
the potential borrower. 

                            LIBRARIES
     The applied and abstract knowledge accumulated by humankind 
is collected and stored in libraries.  All the other assets of 
our species, other than the very human beings, can be replaced 
rather quickly if destroyed.  But were the contents of all 
libraries to be destroyed, progress would be set back thousands 
of years.  
      A librarian -- an expert on libraries -- knows the general 
rules and outlines of this maze of knowledge, but usually stands 
on the sidelines while you venture in.  Sometimes a librarian 
knows the  specific location of the knowledge that you seek.  But 
more often the librarian knows the directions you should go -- 
which catalogs you should consult, and which reference tools you 
should use.  
     Deciding when to go to the library yourself and when to 
consult experts will depend upon such factors as the utility to 
you of the money you would pay to experts, your skill at using 
the library, and the type of question before you and the degree 
of expertise of experts.  Using a library effectively is a 
fascinating challenge.  It is  much more interesting than I ever 
thought it could be when I took the tour given to new students at 
the university when I arrived as a freshman.  


                           REFERENCES
     Armstrong, J. Scott: "Evidence on the Value of Experts in 
Forecasting:  The Seer-Sucker Theory", xerox, 1979, p. 1. 
     Cerf, Christopher and Victor Navasky, The Experts Speak, 
(New York: Pantheon, 1984).
     Faust, David, and Jay Ziskin, "The Expert Witness in 
Psychology and Psychiatry", Science, vol. 241, July 1, 1988, 
pp. 31-35.  
     Harmon, Paul and David King, Expert Systems (New York:  John 
Wiley, 1985). 
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