ISR11
Scientific Report No. ISR-11 Information Storage and Retrieval
An Experimental Investigation of Automatic Hierarchy Generation
chapter
G. Blomgren
A. Goodman
L. Kelly
Harvard University
Gerard Salton
Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government.
VIII-6
Term 3
Parents (None)
Brothers 1
Sons
Term [OCRerr]
Parents 1, 3
Brothers 2
Sons (None)
A query containing terms 1 and 3 is specialized by adding term 1!.
For a given matrix S, varying the cutoff [OCRerr]ral[OCRerr]e results in different
hierarchies. Referring to the above exa[OCRerr]nple, other values of K give the
following graphs:
K = 0.25 K = 0.35 K = 0.60
O$[OCRerr]O o--o o--o
o--o o--o
K = 0.65
o--o
o[OCRerr]-o
K = 0.70
when K = 0, all concepts are brothers. As K increases from zero and
reaches the region be[OCRerr][OCRerr]en S and , the brother relationship
jk
between T. and Tk becomes a parent-son relation; as K increases frrther,
3
these concepts become unrelated. If no entry in the S matric is equal
to 1.0, then when K = 1 all concepts are unrelated.