1. 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

2. 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

3. Assignment 1 What is information, according to your background or area of expertise?

4. Types of Information Differentiation by form. Differentiation by content. Differentiation by quality. Differentiation by associated information.

5. 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

6. 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

7. 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

8. 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

9. Information Hierarchy Wisdom Knowledge Information Data

10. 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

11. 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?

12. Origins Very early history of content representation –Sumerian tokens and “envelopes” –Alexandria - pinakes –Indices

13. 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

14. 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

15. 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

16. What kinds of information are there? Text –books, periodicals, WWW, memos, ads –published/refeered Film Photos, other Images Broadcast TV, Radio Telephone Conversations Databases

17. How much information is there? (Estimates courtesy Hal Varian and Peter Lyman: http://www.sims.berkeley.edu/emc)

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

19. Print 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)

20. 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

21. Film and Image Film –Photographs = 410 Petabytes per year –Movies = 16 Terabytes (Commercial Production of about 4000 films) –X-Rays = 12 Petabytes

22. 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

23. 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

24. Totals Stored Per Year Medium 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 357 351 Film Photographs 410,000 100,000 Cinema 16 16 X-Rays 12,000 12,000 SUBTOTAL 422,000 112,016 Optical Music CDs 58 40 Data CDs 3 3 DVDs 22 22 SUBTOTAL 83 65 Magnetic Camcorder 300,000 300,000 Disk drives 2,555,000 1,000,20 SUBTOTAL 2,855,000 1,300,200 TOTAL 3,277,440 1,412,632

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

26. Internet Traffic Nov ‘92Apr ‘95

27. 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...

28. 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

29. Internet Hosts (000s) 1989-2006 Source: Vint Cerf

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

31. 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 Source: Vint Cerf

32. Language Distribution of Web Content Source: Jack Xu: Excite

33. Language Distribution on a 634 Million Web Pages Corpus

34. Sources on Information, Computer, and Network Use http://www.sims.berkeley.edu/research/projects/ho w-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/coff man/index.html –The size and growth rate of the Internet by K.G. Coffman and Andrew Odlyzko

35. 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)

36. 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)