Info & Interaction Design:
Visual Information

Mick McQuaid



Visual Information


〈 Pause for Bertin slideshow 〉

Visual information example

Thanks to the two students who worked with me on this study of one student’s solution to the Bertin exercise. This study is more detailed than what I expected you to do in class but serves to illustrate the process.

bertin exercise example

The Invariant

The invariant is represented by the title

The components

The components are the things that vary in the graphic

Retinal Variables

The retinal variables are the things that form an image on our retinas

Bertin’s Theory

It should not be surprising that information design owes so much to a cartographer. This is one of two fields, the other being social network analysis, with the most influence on building information containers today. The remaining sections of this chapter explore Bertin’s theory of information graphics.


The word theory is used to mean many things. To obtain a useful definition, it might be helpful to consider what Stephen Hawking says about theory in A Brief History of Time on page 7.

Note that Hawking is giving what we might call a normative definition, telling us what a theory should be. There might be plenty of things parading around under the theory banner that could be classed as bad theory. Note also that Hawking requires that a theory both describe and predict. Bertin does both of these things, with a detailed description of graphical information and using a concept called efficiency to predict outcomes.


Bertin defines efficiency as a measure of how quickly the process of reading a graphic can be completed and defines the process in some detail under the influence of (then) contemporary philosophy. Let’s read some information graphics now to get an idea of what this might entail.

Categories of information graphics

Bertin describes four categories of graphics: diagrams, networks, maps, and symbols. It is the use of the last three categories, coupled with the detail in Bertin’s theory, that persuade me that here is a good foundation for describing information architecture.






Recall my earlier question about adjuncts to efficiency. The main adjunct in my opinion is an exhaustive depiction of what it means to simplify information using retinal variables at the most detailed level possible.

A Picasso nude exemplifies simplicity

Example: Swim lane diagrams


Bertin, Jacques. 2011. Semiology of Graphics: Diagrams, Networks, Maps (English Translation). Redlands, CA: ESRI Press.



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