I really like pictures.

The most visited page on this site is one about Rich Pictures.

I regularly pick out interesting Infographics.

One of my favourite books at home is called Information is Beautiful which is named after the popular website.

Why? Because "a picture is worth a thousand words", or at least that’s the axiom I tell myself.

I wonder, though, whether this is really true.

If it were really true we’d spend much more time drawing, and far less time writing words. Yet writing words is what we do and do a lot (much like I’m doing now).

Many think that the saying is ancient and oriental, but the evidence for that is somewhat sketchy at least the literal translation. What can be said is that it was used in the 1920′s, became popular in the 1940′s and continues to be a preferred phrase. The variation on this "A picture speaks a thousand words" didn’t come until the 1970′s:

Just because something is popular, and just because it appears to be true doesn’t mean that it is true.

In order to assess the validity of the axiom I set off down the scientific route. What research was there for the value if diagrams?

If it were to be true then there would be some clear evidence for a picture being a much better way of communicating than a set of either spoken or written words.

I was always taught that there were three types of learners: visual learners, auditory (listening) learners and kinaesthetic (doing) learners. So I wondered whether there might be some mileage in the research done into that particular subject. If visual learners are stronger than auditory learners then it would add weight to the premise. But it turns out that learning styles might be one of my anti-axioms. So I gave that up as a dead-end.

My next port of call was to think of one particular diagram type and see whether there was any science behind the value of a particular technique.

Most of the pictures I draw are really diagrams with the purpose of communicating something.

As a fan of mind maps as a diagramming technique I wondered whether there was any clear evidence of their value. Back in 2006 Philip Beadle wrote an article in The Guardian on this subject and the use of mind maps in education:

The popular science bit goes like this. Your brain has two hemispheres, left and right. The left is the organised swot who likes bright light, keeps his bedroom tidy and can tolerate sums. Your right hemisphere is your brain on drugs: the long-haired, creative type you don’t bring home to mother.

According to Buzan, orthodox forms of note-taking don’t stick in the head because they employ only the left brain, the swotty side, leaving our right brain, like many creative types, kicking its heels on the sofa, watching trash TV and waiting for a job offer that never comes. Ordinary note-taking, apparently, puts us into a "semi-hypnotic trance state". Because it doesn’t fully reflect our patterns of thinking, it doesn’t aid recall efficiently. Buzan argues that using images taps into the brain’s key tool for storing memory, and that the process of creating a mind map uses both hemispheres.

The trouble is that lateralisation of brain function is scientific fallacy, and a lot of Buzan’s thoughts seem to rely on the old "we only use 10% of the neurons in our brain at one time" nonsense. He is selling to the bit of us that imagines we are potentially super-powered, probably psychic, hyper-intellectuals. There is a reason we only use 10% of our neurons at one time. If we used them all simultaneously we would not, in fact, be any cleverer. We would be dead, following a massive seizure.

He goes further:

As visual tools, mind maps have brilliant applications for display work. They appear to be more cognitive than colouring in a poster. And I think it is beyond doubt that using images helps recall. If this is the technique used by the memory men who can remember 20,000 different digits in sequence while drunk to the gills, then it’s got to be of use to the year 8 bottom set.

The problem is that visual ignoramuses, such as this writer, can’t think of that many pictures and end up drawing question marks where a frog should be.

Oh dear, another cul-de-sac. In researching the mind-map though I did get to a small titbit of evidence, unfortunately from wikipedia (not always the most reliable source:

Farrand, Hussain, and Hennessy (2002) found that spider diagrams (similar to concept maps) had a limited but significant impact on memory recall in undergraduate students (a 10% increase over baseline for a 600-word text only) as compared to preferred study methods (a 6% increase over baseline).

That’ll do for me for now, it’s not "a thousand words" but it’s good enough for my purposes.

Why am I comfortable with just a small amount of evidence? Because this is one of those axioms where it’s not only about scientific proof.

Thinking about pictures in their broadest sense there are certainly pictures that would take more than a thousand words to describe them.

There are pictures that communicate emotions in a way that words would struggle to portray.

There are diagrams which portray a simple truth in a way that words would muddle and dilute.

In these situations the picture is clearly worth a lot of words, but our words would all be different. The way I would describe an emotional picture would be different to the words you would use. So it’s not about the number of words, but the number of different words.

This little bit of research has got me thinking though.

How often do we draw a diagram thinking that everyone understands it, but we’re really excluding the "visual ignoramuses" (as Philip Beadle describes himself). or the "visually illiterate" (as others describe it)?

In order to communicate we need to embrace both visual literacy and linguistic literacy in a way that is accessible to the audience. I used to have a rule in documentation, "every diagram needs a description". The PowerPoint age has taken us away from that a bit and perhaps it’s time to re-establish it so that we can embrace the visual and the literal.

I’m happy to keep this as an axiom, but I need to be a bit more careful about where I apply it.

To conclude: