Introduction. information theory - Shannon and Weaverapplication to visual communication; process theorynoise: redundancy, entropylimitations of process theoryconclusion - process theory and semiotics .. Warren Weaver. American scientist and mathematiciandirector of the Division of Natural Scie
1. Communication Theory and Semiotics Graphics 1
2. Introduction information theory - Shannon and Weaver
application to visual communication; process theory
noise: redundancy, entropy
limitations of process theory
conclusion - process theory and semiotics .
3. Warren Weaver American scientist and mathematician
director of the Division of Natural Sciences at the Rockefeller Foundation, 1932 - 1955
influential in the application of science; genetics, agriculture, medicine and molecular engineering and many other fields
early work on machine translation and mass communication - ‘tower block analogy’
co-author with Shannon of The Mathematical Theory of Communication, published 1949 .
4. Claude Elwood Shannon American mathematician and electronics engineer
1937, aged 21, his Master’s thesis established mathematical basis of digital circuit design and hence the modern computer
had varied interests
created a mechanical mouse that could learn a maze
invented a motorised pogo stick
beat blackjack and roulette at casinos using game theory and computation
applied his theories to the stock market and was very successful! .
5. Shannon and Weaver, 1949 during WW2 Shannon joined Bell Telephone Labs
worked on fire-control systems (anti-missile targeting) and cryptography
met and worked with many great scientists;
people involved with earliest satellites, signal theory, first digital computers, the inventors of the transistor
became friends with Alan Turin, discussed cryptography with him
treated the problems he encountered as the need to distinguish ‘signal’ from ‘noise’
by considering the role of ‘data’ in contrast to ‘signal processing’ he founded the field of ‘information theory’
hence laid the foundations of all modern communication .
6. Shannon and Weaver, 1949 ‘The Mathematical Theory of Communication’
based largely on the work Shannon had published previously
Weaver added a philosophical context to the work, showing its wider applications, and used his influence to popularise it
theory focuses on the best way for the sender to encode information before sending it
realised that all communication, including human language, could be measured in the form of a rate of ‘bits per second’…
…and that all ‘channels of communication’ had their own maximum capacity, also measured in bits per second
considered the role of ‘noise’ in disrupting integrity of information
limited channel capacity and noise lead to uncertainty…
…developed the concept of ‘information entropy’ as a measure of uncertainty in a message .
7. Shannon and Weaver, 1949 what limits the capacity of the ‘channel’?
where might noise be introduced between sender and receiver?
8. process theory Shannon and Weaver’s contribution has been applied to many areas
marketing and advertising
if graphic design is concerned with ‘effective visual communication’ then information theory may help us analyse and discuss our work; ‘process theory’…
10. process theory all communication can be considered as a process in which message follows path from sender to receiver
11. communication problem levels Shannon and Weaver discuss three ‘levels’ of communication problem: technical, semantic, effectiveness
how accurately can we communicate the message?
which system to use to encode the message?
can the receiver use that system?
which ‘language’ to use?
how accurately does our ‘language’ convey the meaning we intend?
how much can be lost whilst still preserving the meaning?
does the message have the effect we want to achieve?
what can we do if it doesn’t? .
12. communication problem levels - graphics addressing the technical level;
‘scope’; which information, how much, and its extent
medium; eg newspaper adverts, direct mail, tv and radio
demographics, identifying the audience, cultural norms
addressing the effectiveness level
often considered as an ongoing aspect of the technical level:
previous lessons learned
market research, focus groups
relationship between technical level and effectiveness level can be described as ‘feedback’
specification adjusted and fed back to designer
Shannon and Weaver did not include this in their original work…
13. communication problem levels - graphics
14. noise: redundancy and entropy noise - anything ‘added’ between sender and receiver
obvious source of noise is reproduction; eg newspaper print; technical
noise at effectiveness level comes from things like audience distractions, product placement, dimensions of signage, etc
redundancy - repeating all or part of the message
newspaper headlines contain little redundancy; ‘Child Killer Held’
redundancy can clarify the message; providing pictogram and text
entropy - measure of uncertainty contained in message
an ambiguous message has a high entropy
noise dilutes a message and hence increases entropy
a ‘long’ message does not necessarily contain a lot of information
redundancy makes the message longer, but usually reduces ambiguity, so can reduce entropy .
15. the semantic level Shannon and Weaver’s model was based in mathematics and communication engineering;
grounded in a field where the semantic level is largely predetermined
choice of language depends on application, eg; a human language, an electronics communication protocol
accuracy of language informs choice - you wouldn’t chose a human language for a fire-control system or vice versa!
‘robustness’ of the language (and hence how much information can be lost without losing the message) are engineering constraints;
so the process model tends to treat the message as something to be encoded, transmitted and received
does not have much to say about the message itself…
16. limitations of process models models like Shannon and Weaver’s treat communication as a linear process;
a message needs to be passed from A to B
encode the message in a suitable format
anticipate problems such as noise and compatibility
build in robustness with redundancy
analyse the result with measures such as entropy
as a result the meaning of the message is determined before it leaves the sender
process models consider minimum and maximum factors required to maintain integrity of the meaning such as;
the minimum redundancy required
the maximum information that can be carried by a channel
17. process theory and semiotic theory as we’ve seen, semiotics considers the role of the ‘reader’ when interpreting the ‘text’, eg;
red can be associated with evil or with good luck depending on culture
red can mean danger and stop, or can mean romance and passion depending on context, within the same culture
in semiotic approaches, the meaning of the message is fixed by the receiver, not by the sender!
this takes into account noise introduced between sender and receiver
also takes into account differences in culture
also takes into account different associations in the same culture
when combined, process theory and semiotics provide a complete framework for analysing effective visual communication…
18. Sources Noble, I. & Bestley, R., 2007. Visual Research: An Introduction to Research Methodologies in Graphic Design, AVA Publishing.
Crow, D., 2003. Visible Signs: An Introduction to Semiotics, AVA Publishing.
Baldwin, J. & Roberts, L., 2006. Visual Communication: From Theory to Practice, AVA Publishing.
Chandler, D., Semiotics for Beginners, http://www.aber.ac.uk/media/Documents/S4B/semiotic.html
http://www2.research.att.com/~njas/doc/shannonbio.html - biography of Shannon with links to his papers