Donald Byrd, School of Informatics and School of Music, Indiana University
rev. late January 2007
¥ Classification
(in the ordinary way) is dangerous to your understanding.
– Classification
ordinarily means hierarchic classification
– Hierarchic
means subdividing cleanly into categories; often subcategories. But...
– Almost
everything in the real world is messy
– Absolute
correlations between characteristics are rare
– Example:
some mammals lay eggs; some are ÒnakedÓ
– Example:
is the piano a keyboard, a string, or a percussion instrument?
– Example:
Ginger Baker says Cream was Ònot really a rock groupÓ
¥
People often say Òan X has characteristics A, B, C, DÉÓ
¥ They nearly always mean Òan X has characteristic A [or B or C orÉ], and usually also A, C, DÉÓ
– NB:
most fundamental one may not be the one mentioned first
¥ Important special case: partitions (ÒflatÓ classifications, without subcategories)
– Example:
ÒIs Bred still in love with Jan, or is he having an affair with Operetta?Ó
– Example:
arguments against faster-than-light travel
¥
Messiness of the real world leads to:
– People
who know better claiming absolute correlations
– Arguments among experts over which characteristic is most fundamental
– ÒIs
it this or that or that?Ó questions that donÕt have an answer
– Don
changing his mind
¥ So should we abandon hierarchic classifications?
– Of course not:
they're much too useful
– But
be on your guard for misleading ones!