L.A.T.C.H

Researching the development of scientific visual languages inevitably involves the collecting of a huge number of images. The challenge is to then adopt a methodical approach to analysing and making sense of those images.

Information designer Richard Saul Wurman devised the L.A.T.C.H method for organising visual information (Wurman, 1996), with each of the letters in the acronym standing for a different approach to organising the same set of images.

  • Location – with the information organised into groups dependent upon it’s geographic location.
  • Alphabet – information arranged in alphabetical order.
  • Time – information arranged in chronological order.
  • Category – information organised into defined categories, perhaps based on subject matter, information type, etc.
  • Hierarchy – information arranged in a hierarchical order, perhaps dependent upon size, age, etc.

In terms of scientific conceptual figures, arranging the figures based on location, alphabet or hierarchy is not particularly appropriate. Categorising the figures proved to be extremely subjective, with figures fitting into several of the categories that were proposed (2D versus 3D, hand-drawn versus computer-generated, greyscale versus colour) and the resulting groupings not really providing any additional insights. As it was the historical development of the figures that was of interest, using the Time component of the L.A.T.C.H method, and arranging the figures chronologically, seemed to be the most logical approach, and indeed proved to give significant insights. The approach is demonstrated here, using conceptual figures depicting blood circulation in humans.

Blood circulation figures

It should be noted that in 1628, William Harvey proved that the heart acted as a pump in  a double-loop circulation system, with blood flowing along vessels in one direction only. Prior to this date, there was no concept of blood continuously circulating the body. Instead it was assumed that blood was generated in the heart and then absorbed in the liver. Harvey’s discovery can certainly be regarded as a paradigm shift in science, and the visual representation of the blood circulation system is its visual equivalent, the visual paradigm*. Reviewing figures of blood circulation chronologically can reveal how this visual paradigm developed.

Prior to 1628, blood vessels were represented as lines or pipes, with no indication of circulatory flow.

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From l to r: Andreas Vesaliuis (1543); Felix Platter, after Vesalius (1583); Robert Fludd, after Helkiah Crooke (1623)

 

Following Harvey’s discovery, the figures change and, over time, become less anatomical and more diagrammatic in their depiction of the human torso and associated organs and blood vessels.

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From l to r: William Cowper (1698); Jean Bonhomme (1748); John Bell (1800); James Curry (1815).
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From l to r: Joseph Maclise (1844); after Weiss (1950); from Marshall & Hughes** (1965); Christiansen, Medical Art Services (2015).***

The colour differentiation of the veins and arteries, shown in blue and red when colour printing allowed, and the representation of organs by networks of blood vessels became the visual motifs that are instantly recognisable to a knowledgeable audience. It can be seen from the examples shown below that this visual paradigm has varied little in its essential elements over the last 200 years.

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Left: James Curry (1815). Right: Christiansen (2015)

Visual paradigms are present in all fields of the earth and life sciences, although not all are as well known as the representation of blood circulation. This paradigm has become familiar to many outside of scientific circles, as the examples below, of figures created for children or the general public, demonstrate.

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From l to r: Circulatory system diagram for secondary school-age children (2016); Circulatory system poster for primary school-age children (2014); Pulmonary circulation diagram for the general public, British Lung Foundation (2016).****

 

* For an article that explains what constitutes a visual paradigm, see this blog post.

*** Unless stated otherwise, all images obtained from Wellcome Images (wellcomeimages.org)

**** Images obtained from: acescorers.com.sg/blog/2016/03/30/circulatory-system/ ; tes.com/teaching-resource/the-circulatory-system-poster-6400655 ; blf.org.uk/support-for-you/pulmonary-hypertension/what-is-it

 

References
Wurman, Richard S. (1996) Information Architects. Zurich. Graphis Press.
**Marshall, P.T. & Hughes, G.M. (1965) The Physiology of Mammals and Other Vertebrates. Cambridge. Cambridge University Press.