What is Information? The Nature, Growth and Characteristics of Information University 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 SourceDecodingEncodingDestination Message Channel StorageSource Decoding (Retrieval/Reading) Encoding (writing/indexing) Destination 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:

How Much Information? Stored Information –Print –Film –Optical –Magnetic Communicated –Internet –Broadcast –Phone –Mail

Print Annual Production –Books 968,735 = 8 Terabytes (compressed image) –Newspapers = 25 Terabytes –Journals = 2 Terabytes –Magazines = 10 Terabytes –Office Documents 12x10^9 pages = 312 Terabytes –TOTAL 357 Terabytes (1824 scanned, 35 text)

Print 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 = Petabytes Video Tape 355,000,000 = 1420 Floppy disks = 0.07 Removable disks = 1.69 Hard Disks = 500

Totals Stored Per Year Medium Type of content Terabytes/Year Terabytes/Year Upper Bound Lower Bound Paper Books 8 7 Newspapers Periodicals Office documents SUBTOTAL Film Photographs 410, ,000 Cinema X-Rays 12,000 12,000 SUBTOTAL 422, ,016 Optical Music CDs Data CDs 3 3 DVDs SUBTOTAL Magnetic Camcorder 300, ,000 Disk drives 2,555,000 1,000,20 SUBTOTAL 2,855,000 1,300,200 TOTAL 3,277,440 1,412,632

Internet Traffic -- Historical Nov ‘92 Apr ‘95 Dec 1996 = 1500Tb Dec 1997 = 3000Tb

Internet Traffic Nov ‘92Apr ‘95

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 messages per year = 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) Source: Vint Cerf

Projected Voice and Data Traffic Gb/s Source: America's Network, May 15, 1998

Users on the Internet - May 1999 CAN/US M Europe M Asia/Pac M Latin Am M Africa M Mid-east M Total - 165M Source: Vint Cerf

Language Distribution of Web Content Source: Jack Xu: Excite

Language Distribution on a 634 Million Web Pages Corpus

Sources on Information, Computer, and Network Use w-much-info-2003/ www/numbers.html –Statistical snippets extracted from the news –Vint Cerf’s pages man/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)