Softwaretechnologie für Fortgeschrittene Teil Thaller Stunde VI: Information revisited Köln 4. Februar 2010

Claude Shannon: "A Mathematical Theory of Communication", Bell System Technical Journal, Enthält eine quantitative Definition von Information. Zweck: Wie kann ein Signal zwischen einem Sender und einem Empfänger mit dem geringstmöglichen Aufwand "korrekt" übertragen werden. Information 2

Shannon hat also eine technische Definition von "Information", die die Bedeutungsebene völlig ausklammert. Er betont, dass "die semantischen Aspekte der Kommunikation für die ingenieurwissenschaftliche Seite irrelevant sind". Information 3

Nahezu alle mir bekannten Lehrbücher der Informatik beginnen mit Shannons Definition der Information. Räumen aber ein, dass die ingenieurwissenschaftliche Definition von Information defizitär sei. Insbesondere: Information 4

(1) Bildet sie nur einen Teil des intellektuellen Umfanges des Konzepts "Information (syntaktisch, semantisch, pragmatisch) ab. (2) Gibt es dagegen keine operable Definition die dieses Konzept in seiner vollen Breite abdeckt. Aber: Die vorhandenen Konzepte reichen aus, um Information auf einem Digitalrechner so darzustellen, dass man sie sinnvoll verarbeiten kann. * Information 5

Informationsebenen Syntax: Beziehungen der Zeichen untereinander. Semantik: Beziehungen zwischen Zeichen und Gegenständen. Pragmatik: Beziehungen zwischen Zeichen und ihren Benutzern. 6

Bernard Favre-Bulle Information und Zusammenhang. Informationsfluß in Prozessen der Wahrnehmung, des Denkens und der Kommunikation. Springer: 2001 Information und Wissen 7

Daten sind speicherbare Angaben - 22°C. Information stellt Daten in einen Kontext: "In diesem Hörsaal herrscht eine Temperatur von 22°C". Dieser Kontext ist jedoch noch fest (und für alle Informationsempfänger identisch). Information und Wissen 8

Wissen ist das Ergebnis von Erkenntnisprozessen. Es bezieht die praktische Anwendung der Daten und Informationen ein. Es muss nicht "absolut wahr" sein, sondern adäquates Handeln zu ermöglichen. Z.B. die Entscheidung einen Pulli (nicht) auszuziehen, um sich angenehm zu fühlen, ohne sich zu erkälten. Information und Wissen 9

* Ladder of Knowledge 10 Weisheit Wissen Information Daten

Testfile in Word 2007

Testfile in Word 2003 (2007)

Testfile in Open Office ODT

Testfile in PDF

Measuring the pages … Cut out page from rendering surface. Scale to common dimensions: 371 +/- 1 x 521 +/- 1 Measure 1.The leftmost and lowest completely black pixel in the letter A starting the first line of the main text. 2.The leftmost and highest completely black pixel in the letter E starting the first line of the text in the footnote. 3.The geometrical centre of the period at the end of the main sentence. 4.The geometrical centre of the period at the end of the footnote text.

Measuring Word 2003 (i)= 45 / 134; (ii) = 57 / 470; (iii) = 215 / 322 ; (iv) = 254 / 483

Measuring Word 2007 (i) = 45 / 134; (ii) = 57 / 470; (iii) = 215 / 322 ; (iv) = 254 / 483

Open Office ODT (i)= 44 / 132; (ii)= 52 / 469; (iii) = 214 / 320 ; (iv) = 247 / 482

PDF (i)= 45 / 130; (ii)= 59 / 467; (iii) = 215 / 317 ; (iv) = 254 / 480

Summary I The comparison of the four renderings of the example pages described above seem to indicate clearly, that a migration from the Word family of formats to PDF is a better way to preserve the content of the document, than a migration to the Open Office format.

Measuring Word 2003 Relationship tagged explicitly. Text / footnote separation clear. Rendering / layout not (totally) predicatble. Footnote indicator unpredictable.

Measuring Word 2007 Relationship tagged explicitly. Text / footnote separation extremely clear. Rendering / layout pretty predictable. Footnote indicator not predictable.

Open Office ODT Relationship tagged explicitly. Text / footnote separation extremely clear. Rendering / layout a little bit predictable. Footnote indicator predictable.

PDF Relationship expressed by layout. Text / footnote separation missing. Rendering / layout very much predictable. Footnote indicator predictable.

Summary II The comparison of the four internal structures of the example pages described above seem to indicate clearly, that a migration from the Word family of formats to PDF is a worse way to preserve the content of the document, than a migration to the Open Office format.

Small technical note Do not forget, that the whole movement started by SGML, carried into the WWW by HTML, transferred to content by the TEI and started XML as a basic empowering technology assumes that rendering is NOT particularly relevant. Separation of content and form. *

Cologne Information Model

Data which represent stored information do so in two forms: 1.As a set of tokens, which describe atomic items of information. 2.By a set of independent parameters, which describe, in a formalized way, the semantic interpretation of these items of information. Assumption I

1.Most algorithms today are based on data types, which are reflecting hardware characteristics ( char, int, float... ). 2.Objects, which are constructed from these data types, are transient concepts, which are meaningful only within a specific implementation / environment. 3.What we would need are considerably higher order objects, which are persistent by themselves and independent of a specific implementation / environment. Assumption II

The need formulated as assumption II can be fulfilled using assumption I. Assumption III

(1)I = i (D, S, t) (2) I 2 = i (I 1, S 2, t) (3) I x = i (I x-1, S x, t) (4) S x = s (I x-1, t) (5) I x = i (I x-α, S x-β, t) (6) I x = i (I x-α, s(I x-β, t), t) Generalisation of Langefors Infological Equation

(1) Biggin (2) Biggin (3) Biggin (4) Biggin Which of the chunks are more similar to each other: (1) and (2) or (1) and (3)? Four texts

Coordinates:

Liber exodi glosatus

Generalization 1 35 Biggin Visualization {bold, italic} Interpretation {surname, topographic name}

Generalization 2 36 Series of atomic content tokens Conceptual dimension 1 Conceptual dimension 2

Generalization 3 37 { T, C 1, C 2 }

Generalization 4 38 { T, { C 1, C 2, …, C n } }

Generalization 5 39 { T, C n } (1) Texts are sequences of content carrying atomic tokens. (2) Each of these tokens has a position in an n-dimensional conceptual universe.

Generalization 6 40 { X, Y, C n }

Generalization 7 41 { T 1, T 2, C n } (1) Images are planes of content carrying atomic tokens. (2) Each of these tokens has a position in an n- dimensional conceptual universe.

Generalization 8 42 I ::= { { T 1, T 2, … T m }, C n } (1) Information objects are m-dimensional arrangements of content carrying atomic tokens. (2) Each of these tokens has a position in an n- dimensional conceptual universe.

Generalization 9 43 I ::= {T m, C n } (1) Information objects are m-dimensional arrangements of content carrying atomic tokens. (2) Each of these tokens has a position in an n- dimensional conceptual universe. (3) All of this, of course, is recursive …

Danke für heute; Schöne Ferien! 44