CHAPTER 4-1
                   CLASSIFYING THINGS SENSIBLY


                    PHOBIAS IN BRITONS FALL INTO 130 TYPES
     
     A half million Britons are afraid of things ranging from 
blood to barbershops, with some even afraid of being afraid. . . 
.  Britain's phobia victims suffer from at least 130 different 
types of irrational fear. . . . British Medical Association 
...said  
     Fear of spiders, matches, green leaves, pictures of ships in 
distress, birds and feathers, cats, dogs, mice, frogs, toads, 
wasps, snakes, blood and thunder were among disabilities haunting 
people.  (New York Times, Oct. 14, 1969, p. 13)


     Did you ever forget something you wished you had taken with 
you on a trip?  Did you ever find yourself assigned to a school 
class, or to an athletic team, that was obviously unfitted for 
your abilities?  These are failures of classification.
     Classification -- sorting out a collection of people or 
objects, and developing a set of categories into which you divide 
the collection -- is a more important and more difficult part of 
our thinking than we usually recognize. If you treat different 
things in the same way, or similar things in different ways, you 
risk dealing badly with some or all of them.  
     Making up lists of items seems an unexciting topic and 
activity.  Yet making lists of people who should be called, 
equipment that will be needed, ideas you must consider -- this 
work is crucial in organizing and managing any activity, 
especially your own life.  
     The computer is an extraordinary help in classification, 
nowadays.  With it it you can maintain lists in handy form, and 
add and subtract items with ease.  (This is only one of the many 
ways in which the computer serves as the greatest advance in 
thinking since people began to write on papyrus, and began to 
create libraries of ideas.) 
    To jump ahead of the story, there are two basic elements of 
classification:  1) constructing the categories so that they fit 
your purposes well, and 2) assigning the elements at hand to the 
appropriate categories. 
     Measurement and classification are closely connected.  
Indeed, measurement is a special kind of classification that uses 
numbers in order to obtain additional precision in 
classification.  
     Consider a classification of taxi rides for the purpose of 
comparing the service of various taxi companies.  You must decide 
on a set of labels for the pigeon-holes in which you can file 
each ride.  Will it be just "good" and "bad"?  Or just "very 
good", "satisfactory" and "bad"?  Will you classify on several 
dimensions such as promptness and courtesy?  Perhaps you will 
choose to use a quantitative measurement scale, from 1 to 10, and 
perhaps make measurements on both the promptness and courtesy 
dimensions.  
     Some philosophers have advised that you form a 
classification by deep examination of the objects you are 
attempting to classify, attempting to find some general 
principles related to the inherent nature or purpose of the 
objects.  I side here with the working scientists, however, and 
suggest that you form your classification with close attention to 
your purposes in making the classification.  This has the great 
advantage of giving you a basis on which to compare the value of 
different classification schemes.  True, some classification 
schemes must serve many individuals and organizations -- an 
example being the decennial census -- and therefore no single 
purpose can be taken as a guide.  But even in making decisions 
about how to classify people for the census, particular purposes 
are referred to, such as the fact that the data serve as the 
basis for congressional districting. 
     (Throughout this book you will find that I consistently come 
down on the side of considering the particular aims and goals of 
the work at hand when making decisions of all kinds.  Partly this 
is my practical bent.  But partly it is my experience that the 
antidote to vagueness and confusion often is attending to 
particular purposes rather than general principles or "esthetic" 
considerations. ) 
     These are some important uses of a classification scheme:
     1) A classification enables you to deal routinely with 
individual cases.  After a doctor has classified a patient as 
having smallpox, the treatment is almost automatic.  Without a 
classification scheme a doctor would have to do an impossible 
amount of study on each patient before selecting a treatment; the 
classification scheme enables the physician to take advantage of 
the accumulated store of medical knowledge about which treatments 
aid which diseases. 
     2) A classification aids summarization.  Once you have 
decided to classify the radio stations in your area into popular 
music, classical music, and talk programs, you can count the 
number in each group and talk generally about the policies of 
each type. 
    3) A classification makes you aware of differences among the 
categories, whether the categories be species of plants, types of 
moods, or varieties of cleanser.  Once you have classified and 
labeled the instances of bad moods you suffer from time to time, 
you can then ask: what are the differences between my angry moods 
and my sad moods?  
     4) A classification clarifies one's understanding.  Remember 
how many times you have gotten into an argument that seemed 
futile, and then you (or even the other fellow!) said: "Let's 
make a distinction between the zilches and the squilches.  What 
you say may be true of the zilches, but it certainly isn't true 
of the squilches."  Often you find that the argument has suddenly 
evaporated and that the two of you agree.  (This fourth point is 
really a summary of the previous three points.) 
     The process of putting people or things into categories also 
has a drawback, however:  One inevitably loses some information.  
For example, assume you have interviewed people in your community 
about racial integration, and you then classify the interviews 
into those for and those against integration.  You thereby lose 
all the shadings of opinions voiced by the interviewees, and the 
richness and variety of their comments.  But unless you classify 
in this manner, you cannot handle the people in groups.  
     The critic says, "How can you talk as if any two different 
people in your survey were exactly the same?"  The better 
question is whether the items are similar enough for your 
purposes; if so, the classification is fruitful.  Mineral oil and 
coffee is the appropriate antidote whether a child who swallows 
furniture polish lives in Vermont or in Louisiana; in that 
instance the difference in geography does not matter at all.  
(But for other purposes the difference in geography is indeed 
crucial.) 
     Every collection can be classified in many different ways.  
For example, I trust that you will not take too seriously the 
scheme by which pitfalls in thinking are classified in Chapter 4-
6; one could categorize those pitfalls in many different ways, 
some more careful and systematic than the classification we use 
here.  
     More than one dimension of classification is necessary if 
more than one dimension helps to distinguish various groups or to 
predict their behavior.  But there is no value in having two 
dimensions if both classify all occurrences in the same way.  For 
example, if all candidates for the baseball team who throw hard 
also throw far, and vice versa, a judgment of whether a player 
either throws hard or throws far will be sufficient. 
     Categories can employ either words or numbers.  It is 
possible to go from words to numbers or the reverse, though the 
process is not symmetrical.  For example, if you have the heights 
of the people in your sample in feet and inches, you can 
arbitrarily choose to call everyone over 5'10 as 'tall', and 
everyone under that height 'short.'  In this way you have 
converted 'quantitative' data into 'qualitative' verbal 
categories.  The numerical cut-off points for the categories 
should be those that are most useful for you.  The New York City 
police force may establish a cut-off height of 5'8" for 
policepersons because it believes that 5'8" is a better cut-off 
point for its purposes than 6'0" or 5'3".     Defining categories 
is a progressive process.  As tough instances come along, you sit 
down and relate them to your final purpose and then amend your 
definitions to cover them.  In establishing these criteria the 
important things to remember are as follows:  First, have a 
reason for your decision; second, relate the decision to your 
ultimate purpose; and, third, refer back to your theory for 
guidance, if you have a theory of what you are doing.      
Changes in classification often change the way we think.  Crime 
statistics sometimes take frightening leaps because the 
classification scheme has been changed (or because the recording 
of crimes has been improved).  This has also been true of medical 
statistics; for example, better medical knowledge and practice 
led to more accurate diagnosis of lung cancer as a cause of death 
and decreased the number of mistaken diagnoses of tuberculosis 
and other diseases (U.S. Public Health Service, 1964: 127-141). 
     The subject of measurement is intimately related to the 
subject of classification.  Some philosophers have scorned any 
scientific thinking that is not expressed quantitatively.  In my 
view that is arrogant nonsense.  But devising and implementing a 
method of measurement often is a significant improvement on a 
verbal classification scheme, and increases the power of your 
thinking.  For example, knowing that there 3000 square feet of 
living space in a house enables you to value it better, and make 
more specific plans about carpeting, than just the label "big".  
The classification of various modes of measurement, and the 
practical aspects of measuring, are too technical to be of 
interest here; for more material on the subject see Simon and 
Burstein (1985). 
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