What is Information? The Nature, Growth and
Characteristics of InformationUniversity of California, Berkeley
School of Information Management and Systems
SIMS 202: Information Organization and Retrieval
What is Information?
• There is no “correct” definition• Can involve philosophy, psychology, signal
processing, physics • Cookie Monster’s definition:
– “news or facts about something”• Oxford English Dictionary
– information: informing, telling; thing told, knowledge, items of knowledge, news
– knowledge: knowing familiarity gained by experience; person’s range of information; a theoretical or practical understanding of; the sum of what is known
Assignment 1
• What is information, according to your background or area of expertise?
Types of Information
• Differentiation by form.
• Differentiation by content.
• Differentiation by quality.
• Differentiation by associated information.
Information Properties
• Information can be communicated electronically– Broadcasting– Networking
• Information can be easily duplicated and shared– Problems of Ownership– Problems of Control
Adapted from ‘Silicon Dreams’ by Robert W. Lucky
Intuitive Notion (Losee 97)
• Information must– Be something, although the exact nature (substance,
energy, or abstract concept) is not clear;
– Be “new”: repetition of previously received messages is not informative
– Be “true”: false or counterfactual information is “mis-information”
– Be “about” something
• This human-centered approach emphasizes meaning and use of message
Information from the Human Perspective
• Levels in cognitive processing– perception– observation/attention– reasoning, assimilating, forming inferences
• Knowledge: justified true belief• Belief: an idea held based on some support; an internally
accepted statement, result of inductive processes combining observed facts with a reasoning process
• Does information require a human mind?– Communication and information transfer among ants– A tree falls in the forest … is there information there?– Existence of quarks
Meaning vs. Form• Form of information as the information itself• Meaning of a signal vs. the signal itself
– What aspects of a document are information?
• Representation (Norman 93)– Why do we write things down?
• Socrates thought writing would obliterate serious thought• Sounds and gestures fade away
– Artifacts help us to reason– Anything not present in the representation can be ignored– Things left out of the representation are often what we don’t
know how to represent
Information Hierarchy
Wisdom
Knowledge
Information
Data
Information Hierarchy
• Data– The raw material of information
• Information– Data organized and presented by someone
• Knowledge– Information read, heard or seen and understood
• Wisdom– Distilled and integrated knowledge and understanding
Information
Where is the Life we have lost in living?Where is the wisdom we have lost in knowledge?Where is the knowledge we have lost in information?
-- T.S. Eliot, “The Rock”
Where is the information we have lost in data?
Origins
• Very early history of content representation– Sumerian tokens and “envelopes”– Alexandria - pinakes– Indices
Origins
• Biblical Indexes and Concordances– Hugo de St. Caro – 1247 A.D. : 500 Monks -- KWOC– Book indexes (Nuremburg Chronicle)
• Library Catalogs• Journal Indexes• “Information Explosion” following WWII
– Cranfield Studies of indexing languages and information retrieval
– Development of bibliographic databases • Index Medicus -- production and Medlars searching
Information Theory
• Claude Shannon, 1940’s, studying communication
• Ways to measure information – Communication: producing the same message at its destination as
that seen at its source
– Problem: a “noisy channel” can distort the message
• Between transmitter and receiver, the message must be encoded
• Semantic aspects are irrelevant
Noise
Channel
Receiver Desti-nation
Message source
Trans-mitter
Information Theory
• Better called “Communication Theory”• Communication may be over time and
space
Noise
Source DecodingEncoding Destination
Message Message
Channel
StorageSourceDecoding
(Retrieval/Reading)Encoding
(writing/indexing)Destination
Message Message
What kinds of information are there?
• Text– books, periodicals, WWW, memos, ads– published/refeered
• Film• Photos, other Images• Broadcast TV, Radio• Telephone Conversations• Databases
How much information is there?(Estimates courtesy Hal Varian and Peter
Lyman: http://www.sims.berkeley.edu/emc)
Gigabyte 10^9 bytes 1000 megabytes
Terabyte 10^12 bytes 1000 gigabytes
Petabyte 10^15 bytes 1000 terabytes
Exabyte 10^18 bytes 1000 petabytes
How Much Information?
• Stored Information– Print
– Film
– Optical
– Magnetic
• Communicated– Internet
– Broadcast
– Phone
• Annual Production– Books 968,735 = 8 Terabytes (compressed image)
– Newspapers 22643 = 25 Terabytes – Journals 40000 = 2 Terabytes– Magazines 80000 = 10 Terabytes– Office Documents 12x10^9 pages = 312 Terabytes
– TOTAL 357 Terabytes (1824 scanned, 35 text)
• Library of Congress Printed book collection– About 18 Million books– About 130 Terabytes (compressed image)– For all of LC we should also assume
• 13M photographs, 5MB each = 65 TB• 4M maps, say 200 TB• 500K files, 1GB each = 500 TB• 3.5M sound recordings, ~2000 TB• Grand total: 3 petabytes (~3000 terabytes)
• Books in Print – 3.2 Million titles– About 26 Terabytes
Film and Image
• Film– Photographs = 410 Petabytes per year– Movies = 16 Terabytes (Commercial
Production of about 4000 films)– X-Rays = 12 Petabytes
Optical Media
• CD-Music 90,000 items = 58 TB
• CD-ROM 3,000 items = 3 TB
• DVD-Video 5,000 items = 22 TB
• Total 83 TB
Magnetic Media
• Audio Tape 184,200,000 = 184.2 Petabytes
• Video Tape 355,000,000 = 1420
• Floppy disks = 0.07
• Removable disks = 1.69
• Hard Disks = 500
Totals Stored Per YearMedium Type of content Terabytes/Year Terabytes/Year Upper Bound Lower Bound Paper Books 8 7 Newspapers 25 20 Periodicals 12 12 Office documents 312 312 SUBTOTAL 357 351Film Photographs 410,000 100,000 Cinema 16 16 X-Rays 12,000 12,000 SUBTOTAL 422,000 112,016Optical Music CDs 58 40 Data CDs 3 3 DVDs 22 22 SUBTOTAL 83 65Magnetic Camcorder 300,000 300,000 Disk drives 2,555,000 1,000,20 SUBTOTAL 2,855,000 1,300,200TOTAL 3,277,440 1,412,632
Current Size of Web
• There are an estimated 2.1 Billion pages on the Web– About 21 Terabytes– About 7500 further Terabytes in web-accessed DBs.
• 610 Billion email messages per year = 11285 TB• Internet Traffic is doubling every 100 days - An
estimated 62 Million Americans now use the internet (US Commerce Dept 1998)
• Radio took 38 years to get 50 M listeners, TV took 13 years, the Net took 4 years...
Internet - Recent Statistics
5 M Level 2 Domains (NW June 1999)
43.2 Million Hosts (NW January 1999)
206/246 IP countries (NW July 1998)
300 Million Users (Newsbytes, Mar 2000)
(830 Million Telephone Terminations)
Source: Vint Cerf
Internet Hosts (000s) 1989-2006
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1989
1991
1993
1995
1997
1999
2001
2003
2005
hosts
Source: Vint Cerf
Projected Voice and Data Traffic
0
5000
10000
15000
20000
25000
30000
1996 1997 1998 1999 2000 2001 2002
VoiceData
Gb/s
Source: America's Network, May 15, 1998
Users on the Internet - May 1999
• CAN/US - 90.65M• Europe - 40.09M• Asia/Pac - 26.97M• Latin Am - 5.29M• Africa - 1.14M• Mid-east - 0.88 M
---------------------------• Total - 165M
CAN/US
Europe
Asia/Pac
Latin Am
Africa
Mid East
Source: Vint Cerf
Language Distribution of Web Content
English J apaneseGerman FrenchChinese SpanishItalian SwedishMalay KoreanPortuguese DutchDanish CzechFinnish RussianPolish HungarianNorwegian EstonianGreek BulgarianCroatian BasqueThai TurkishArabic AlbanianOthers & Unknown
Source: Jack Xu: Excite
Language Distribution on a 634 Million Web Pages Corpus
Language Number of Docs PercentageEnglish 453,685,690 71.5288%Japanese 43,271,080 6.8222%German 32,253,563 5.0851%French 11,107,994 1.7513%Chinese 9,642,450 1.5202%Spanish 6,965,560 1.0982%Italian 5,638,827 0.8890%Swedish 4,392,709 0.6926%Malay 3,619,227 0.5706%Korean 3,200,762 0.5046%Portuguese 3,014,294 0.4752%Dutch 2,745,610 0.4329%Danish 1,911,677 0.3014%Czech 1,428,385 0.2252%Finnish 1,312,932 0.2070%Russian 1,150,127 0.1813%Polish 952,716 0.1502%Hungarian 760,162 0.1198%Norwegian 607,211 0.0957%Estonian 456,613 0.0720%Greek 393,360 0.0620%Bulgarian 392,777 0.0619%Croatian 310,237 0.0489%Basque 258,074 0.0407%Thai 99,691 0.0157%Turkish 81,218 0.0128%Arabic 38,167 0.0060%Albanian 17,779 0.0028%Others & Unknown 44,561,062 7.0256%Total 634,269,953 100%
Sources on Information, Computer, and Network Use
• http://www.sims.berkeley.edu/research/projects/how-much-info-2003/
• http://www.cs.cmu.edu/afs/cs.cmu.edu/user/bam/www/numbers.html – Statistical snippets extracted from the news
• http://www.wcom.com– Vint Cerf’s pages
• http://www.firstmonday.dk/issues/issue3_10/coffman/index.html– The size and growth rate of the Internet by K.G.
Coffman and Andrew Odlyzko
Human Memory
– Landauer 86: Human brain holds 200MB• looked at rate of information intake and rate of
forgetting, and amount of information adults need for normal tasks
– 6B people on earth implies total memory of all people alive about 1,200 petabytes
– Another way: • estimate that people take in a byte/sec• lifetime 250,000 days or 2B sec• result is 2 GB (doesn’t count synthesizing new info)
Information Overload
• “The greatest problem of today is how to teach people to ignore the irrelevant, how to refuse to know things, before they are suffocated. For too many facts are as bad as none at all.” (W.H. Auden)