© Tefko Saracevic 1 The phenomenon of INFORMATION Nature and multifaceted characteristics Tefko Saracevic Rutgers University

© Tefko Saracevic 2 What is information? n We don’t know!! n But: What is energy, matter, gravity, life, intelligence... ? n All - information included - are basic phenomena n How to study them? All studied in terms of: MANIFESTATIONS BEHAVIOR EFFECTS

© Tefko Saracevic 3 Dictionary (Oxford) INFORM: ä to form (the mind...) esp. by imparting, learning, instruction ä to impart knowledge of some fact or occurrence; to tell (one) something INFORMATION: ä the action of informing; the action of telling or... being told of something ä that of which one is apprised or told; intelligence, news

© Tefko Saracevic 4 Interpretations Information: n a complex phenomenon n spectrum of views; variety of interpretations in differing contexts n research in many fields from philosophy to neuroscience n complex relation to other phenomena e.g. knowledge & processes e.g. communication n strong intuitive & context - dependent understanding

© Tefko Saracevic 5 Views of information: polarization - spectrum One end: Exists in structure of material world -- would be there if we exist or not á Inf. as a basic phenomenon in universe as energy & matter á Inf. as a basic aspect of living systems “Life is a knowledge process” Miller Other end: Material world can only become inf. when acted upon by a knower á Inf. as a cognitive phenomenon only á Related to (& restricted to) cognitive processes

© Tefko Saracevic 6 Relations: increase in complexity of cognitive processing Data Information Knowledge Wisdom/ insight á Symbols with some meaning á Conversion, interpretation á Integration, embedding in private & public á Connections, higher interpretations

© Tefko Saracevic 7 “Information journey” From Data to Information to Knowledge to Wisdom/insight è Increased complexity requiring cognitive skills, past intellectual history, intelligence... è Processing into new patterns, relationships è Under contextual and cultural dependency è Interplay between private and public knowledge - RECORDS

© Tefko Saracevic 8 Scholarly treatment - theories of information n Variety of theories, reflecting –different points of view, departure –different focus & restrictions on given characteristics n Restrictions provide framework for theory, interpretation... –Common approach in science n Any restriction, interpretation has limitations, critics n No comprehensive theory yet n But knowledge on behavior, effects advancing

© Tefko Saracevic 9 Theories... characteristic, restriction emphasized W Uncertainty - inf. theory –concentration on probability of signals –link to entropy (Shanon) W Uncertainty - psychology –contemplated actions (Rapaport) W Uncertainty - inf. science –effects of processing (Hayes) W Truth - logic, philosophy –propositions (Belknap & Anderson) –sentences (Fox) W Meaning - semantics, logic –Texts and contexts (Bar-Hillel & Carnap)

© Tefko Saracevic 10 Theories... W Effectuation, feedback - cybernetics –role in communication (Wiener) W Propagation - epidemic theory of communication –changes in population (Goffman) W Changes in mind - inf. science –effect on structure (Shreider, Belkin) W Changes in knowledge - inf. science –effect on knowledge (Brooks) W Decision making - management –role in process (Yovits)

© Tefko Saracevic 11 Information: mind & brain Cartesian dilemma n Descart: rational mind & physical brain n Cognitive science - mind n Neurophysiology - brain n Convergence: how does brain process information? n Theory of consciousness: –distributive memory, interacting systems –regions in brain where concepts are stored & processed –brain as an “indexer organizing inf. into categories”

© Tefko Saracevic 12 Characteristics of the notion in information science 1. Part of human cognition 2. Has a meaning, content 3. Produced by a generator 4. Recorded, any medium 5. Represented, value-added 6. In context of communication 7. Basis for social interaction 8. Requested, needed; retrieved 9. Effects the recipient (user) 10. A process - transformation A thing, commodity; has value (After Belkin, Buckland)

© Tefko Saracevic 13 Inf. as a PROCESS Information is: * Expandable –addition, change over time * Compressible –represented, integrated... * Transportable –various media, speeds * Diffusive –among populations; “leaks” * Shareable –repeated use by many Inf. systems use these attributes

© Tefko Saracevic 14 Inf. in inf. science... n Information treated as with these characteristics n Each subject of research, models, experimentation n Basis for operations in inf. systems, inf. industry n Each related to professional practice, education n Technology applied to a number n But: at times some treated in isolation, as if others don’t exist - a dangerous mistake

© Tefko Saracevic 15 Inf. in information science (cont.) Again: intuitively well understood, but formally not well stated –Several viewpoints, models emerged n Shannon: source-channel- destination –signals not content – not really applicable n Cognitive: changes in cognitive structures –content processing & effects n Social: context, situation –information seeking, tasks

© Tefko Saracevic 16 Shannon's information theory n Developed a general model for communication systems, and a set of theoretical tools for analyzing such systems, by measuring information in terms of probabilities (numbers)

© Tefko Saracevic 17 Shannon … uncertainty n Defined information in terms of probabilities –developed measure of the information we get from observing the occurrence of an event, BUT ignored any particular features of the event »e.g. flipping a fair coin once will give us events h and t each with probability 1/2, and thus a single flip of a coin gives us - log 2 (1/2) = 1 bit (Binary digit) of information (whether it comes up h or t)  Information measured in bits is the reduction in uncertainty in the mind of the receiver  information (in bits) is the amount of uncertainty a measure eliminates

© Tefko Saracevic 18 Shannon’s impact n Had great impact in treating of digital information as signals –e.g maximizing capacities of channels; coding n Had disappointing impact (despite many tries) where information is connected with meaning, context, humans, values –the ideal to measure information in human terms is elusive –but keep trying …

© Tefko Saracevic 19 Cognitive – basic idea: K(S) + ΔI = K(S + ΔS) (Brookes) n Information when operating on a knowledge structure produces an effect whereby the knowledge structure is changed n “Information is differences that make a difference” (find who said it!) n Actually, it only states the problem – – “unoperational” in information systems –involves cognitive, mental events only –constructivists rejected it

© Tefko Saracevic 20 Inf. manifestations (Buckland) n Information as a process –what someone knows is changed when informed; “the action of informing” (similar as Brookes) »refers to cognitive changes + process of doing it n Information as knowledge –knowledge communicated about x »uncertainty removal a special case »refers to that which is being communicated - intangible n Information as a thing –data, documents with quality of imparting information - tangible »refers to potential information conveyed from objects

© Tefko Saracevic 21 Three senses (from narrowest to broadest) 1. Information in terms of decision involving little or no cognitive processing - Shannon –signals, bits, straightforward data - computing, telecommunication, economics, 2. Information involving cognitive processing & understanding - Brookes –understanding, matching texts 3. Information also as related to context, situation, problem-at-hand, process – Buckland to some extend –users, use, tasks For information science (including information retrieval): third, broadest interpretation necessary Senses of inf. in inf. science

© Tefko Saracevic 22 What is in a book? n for discussion in class

© Tefko Saracevic 23 Cover page of a book: What is in it?

© Tefko Saracevic 24 A chapter in that book

© Tefko Saracevic 25 Here is also a cover page of a book : What is in it?

© Tefko Saracevic 26 A chapte r in that book

© Tefko Saracevic 27 Adequacy? n None of the theories about information are adequate to cover fully information as a phenomenon n Each covers a bit or simply describes manifestation n Shannon’s theory is testable, but reduces “information” to signals only n A scientific theory is one that can be refuted – tested for confirmation, rejection ( Popper)

© Tefko Saracevic 28 Conclusions n Inf. - a complex phenomenon but with recognizable & definable properties n Researched in many fields, from many angles –communication not good n Attributes used in many applications & inf. systems –often with intuitive understanding of properties n Slow convergence of ideas n Work on information of increasing importance - social dimensions

© Tefko Saracevic 29 So we went to study n Human information behavior  “how people need, seek, manage, give, and use information in different contexts” (Pettigrew )  many models, theories, studies on a variety of aspects  extends to study of web behavior n Bibliometrics  “ the study, or measurement, of texts and information” (Norton)  many studies and formal statements about structure & patterns of literatures, citations, authors, journals, texts …  Bradford’s law, Lotka’s law

© Tefko Saracevic 30 to be continued … n We cover these in other lectures and courses n and two 2005 books cover very nicely the topics of theories of human information behavior and integration of information seeking and information retrieval in context –highly recommended

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© Tefko Saracevic 32