Measures of Central Tendency: Mean, Median and Mode
A little something about library arrangement
1. A Little Something about
Library Arrangement
Or Why Things Are
the Way They Are
2. In the beginning
●There were not many books, because
there was no efficient way to make
books.
●Monks would copy books by hand.
●Few people could read or write.
●Only rich people, political or religious
leaders could read and had books.
4. However, once movable type
was invented
●More books were published.
●After the Industrial Revolution, more
common people learned to read.
●Libraries sprang up across the United
States and made books available to
everyone.
5. Soon It Became Important to
Have a Good Way to
Organize Library Materials
6. Many ideas were tried…
●Some tried to arrange book by color;
●Some tried arranging books by size;
●Some arranged the books in the order
in which they were received;
●Some tried arranging the books by
author;
●Some tried arranging the books by title.
7. None of these ideas worked
well.
Then came Melvil Dewey.
8. Melvil Who-ey?
●Melvil Dewey was a librarian who was
frustrated by the lack of standardization
or consistency in the way library
materials were arranged.
●He solved the problem of arrangement
by inventing the Dewey Decimal
System in 1876. We still use this
system more than 137 years later.
9. The Dewey Decimal System
●Dewey’s System uses 1000 numbers to
categorize materials.
●Here are the 10 main categories:
10. History and Geography900-999
Literature800-899
Arts and Recreation700-799
Applied Sciences and
Technology
600-699
Natural Sciences500-599
Languages400-499
Social Sciences300-399
Religion200-299
Philosophy and
Psychology
100-199
General Knowledge000-099
11. Dewey Took the 10 Main
Categories
●And subdivided them into 10s
○000 General Knowledge
■ 010 Bibliography
■ 020 Library and information sciences
■ 030 General encyclopedia works
■ 040
■ 050 General serial publications
■ 060 General organizations and museology
■ 070 News media, journalism, and publishing
■ 080 General collections
■ 090 Manuscripts and rare books
12. He subdivided each of the
main categories into sets of
10, and then he subdivided
each set of 10 into sets of 10.
●This meant he had a total of 1000
numbers that meant different things.
●Each number meant a different subject.
13. But because information
grows every day
●Dewey allowed the use of Decimals to
expand the system as needed.
●Therefore, there is room for subjects
that did not exist when Dewey made
this system.
●Examples: computers, airplanes, Kobe
Bryant, motorcycles.
14. Here are some decimal
numbers
●629.227 Motorcycles
●004.692 E-mail
●973.93 The administration of George W.
Bush
●796.332 Football
●599.75 Cat family (in nature)
●636.8 Domestic cats (our pets)
15. Here’s a lie
●Dewey numbers can only categorize
nonfiction materials
Here’s the truth
●Dewey numbers can be used to arrange
all materials, including fiction, BUT
