The Art (and Science) of Visual Aids
By: Jamie Emerson
Language teachers are many things: linguists, actors, coaches, counsellors, clowns, and more besides. We’re also, all of us, visual designers. From whiteboards to flipcharts to smart boards to projectors, all teachers use, and most teachers make, visual aids to support their language teaching. Understanding the science that underpins this is worthwhile.
As is often the case, this realization came to me from a book. I’m a bibliophile; I’m always reading something, and have a mental plan of what I’ll read next and next and next and next. Books come into and out of my house like I’m running a small publishing house and, in fact, my first full-time job was for a small publishing house. I love the feel of a book, its smell, and its sense of possibility.
Generally, the books that have most influenced my approach to language teaching are straightforward: The English Verb by Michael Lewis, Teaching Unplugged by Luke Meddings and Scott Thornbury, A Course in Language Teaching by Penny Ur, The Practice of English Language Teaching by Jeremy Harmer. But there’s an outlier in the group: a book from User Interface (UI) design expert Jeff Johnson called Designing with the Mind in Mind.
With very accessible language and many, many images, Johnson’s book explains the cognitive psychology which underpins effective visual design. You might use a virtual learning environment (VLE) such as Moodle or Blackboard, or PowerPoint slides, or handouts, or worksheets, or a whiteboard, or a blackboard: there’s something relevant in here for you. Johnson’s book is also helpful if you support students to create visual aids themselves, for example in presentation skills classes.
In this article, I’ll outline two insights from Johnson’s book which had a major impact on me, and explore how they can be applied to the tools of the teacher’s trade. One insight is about something that the human visual system can be bad at, while the other relates to something that the visual system is good at. To emphasize: this is just a small part of Designing with the Mind in Mind and I strongly encourage you to buy or borrow a copy.
Insight 1: Our colour vision is limited
To understand how our colour vision can fail us, and choose visual aids accordingly, it’s important to understand how our colour vision works in the first place. The processes underpinning the account of colour vision in Johnson’s book are part of the Opponent Process theory, which can be distinguished from (but still fits with) Trichromatic theory. As I was researching this article, it was a surprise to find that this is far from settled science. The science and its history are fascinating, but also subtle and complex, so I’m sticking to the broad, introductory account.
At the back of our eyes, in the retina, are two types of cells: rods and cones. Rods are active in low light conditions, and so, as Johnson notes, cones are generally more important in the world of artificial light. There are three types of cone cells, each stimulated by light of different wavelengths. One set responds to low wavelength lights (L), one to medium frequencies (M), and one to high wavelength lights (H). The retina is connected to the visual cortex at the back of the brain by optic nerves. Our retinas are bombarded by light of various wavelengths, and in turn bombard the visual cortex with signals about this light.
Some neurons in the visual cortex specialise in integrating the signals from the M and L cones and others integrate the signals from the H and L cones. This creates what Johnson calls colour-opponent channels: a red-green one, a yellow-blue one, and a black-white, or luminance, channel. As a result, we can perceive greenish-blues and yellowish-reds but not greenish-reds or yellowish-blues.
Even this simple outline is challenging for me, but the main thing I take from it is that our colour perception is the result of the interaction between different light waves. Colour is therefore not perceived in isolation; colours are perceived among other colours. This helps us understand various quirks of our colour vision. For example, the circles below are exactly the same, but they appear to be different shades because of the contrast with their backgrounds.
For more fun examples, explore the Checker-shadow illusion, the Cornsweet illusion and the Chubb illusion.
Factors influencing colour perception
Johnson’s book demonstrates that paleness, size, and distance can all affect our discrimination of colour. Generally, darker colours are easier to differentiate than paler ones. In the example below, the top two squares are dark blue and dark purple, while the bottom two are light blue and light purple (all according to the colour selection tool on MS PowerPoint). The top two are easier to tell apart:
Another factor is the size of the coloured area. The smaller it is, the harder it is to differentiate (Johnson suggests that because text tends to be thin, picking out the exact colour of text is difficult). In the example below, colours of the the biggest shapes are the easiest to distinguish and the smallest ones are the hardest:
Finally, distance plays a role; the closer two coloured objects are, the easier it is to differentiate them:
Johnson’s central point about colour is that our perception of it is inconsistent, and he gives examples like the quality of a screen, the angle of our view, and the surrounding lighting that will further affect our judgement of colour.
Colour blindness
Another major reason to be careful in the use of colour is the fact that 8% of males and 0.5% of females have cone cells which do not function well and are therefore “colourblind” (Simunovic, 2010). This is close to my heart, because I am one of these people. I was in primary school when I was diagnosed as being red-green “colourblind.” Incidentally, colourblind is a misleading term, because it suggests that somebody cannot see colour. In the majority of cases, the colourblind individual still perceives colours; they just struggle to differentiate those in a particular colour-opponent channel. Usually the red-green channel is the problem. Colour vision deficiency is a better name, but colourblind has stuck.
In my case, I was given the Ishihara test at primary school. At the end I was told that the professions of pilot and electrician were now closed to me. For me, I often struggle to tell reds from greens and struggle with pinks, oranges, and browns. Luckily, in the physical world, colours are rarely separated from context. So I know that the stem of a flower is green, even if the colour on its own might look more like brown or red to me. Similarly, I know that on traffic lights, red is at the top, then orange, then green. The colours in isolation might be tricky, but in context they are not.
Application
This is all relevant to teachers when designing visual aids. One of the main jobs of a language teacher is to raise learners’ awareness of features of the target language. This might involve increasing the salience of features visually. It is important to keep in mind that colour will not automatically do this. Take a slide like this for example, used to analyse the components of the present perfect:
Slide A is what not to do. According to Microsoft PowerPoint (which helpfully labels colours with text when you hover your mouse pointer over them), have is in dark orange, the base verb climb is red, and the verb ending –ed is dark green. Without those labels, I’d have no idea. I can detect some subtle differences between the colours, but with effort. However, as we saw earlier, trouble differentiating colours doesn’t only affect colourblind people, especially with the thin shapes of written language.
Slides B and C are better. In B, colour is used to differentiate the base verb and its ending, but the colours aren’t in the same opponent channel. The auxiliary verb is highlighted with bold, rather than colour. In C, bold and underlining are used for the auxiliary verb and the verb ending respectively, leaving red to highlight the base verb form.
However, neither of these are ideal. In his book, Johnson suggests that when creating visual aids on a computer, it is helpful to switch to greyscale to get a sense of how the image might appear to somebody with a colour impairment. With these slides, switching the screen to greyscale shows that colour is still doing some of the work. Slide D shows how colour can be avoided altogether, in favour of other markers.
Insight 2: We seek and use visual structure and our vision is optimised to see structure
My dog is called Shung Shung, and is the offspring of street dogs from Ningbo, China. In my deeply subjective opinion, she’s the best dog in the world. Growing up, I didn’t have a dog, and was somewhat scared of them. I didn’t see myself as a “dog person” until I fostered, and then adopted, Shungy. Now, I’m all in on dogs. As I took care of mine, teaching her to walk on the lead and to be at least somewhat obedient, I was struck by how our interests seemed to differ. Why is this tree, or lamppost, or patch of grass, so interesting for you and so utterly mundane to me? Of course, it’s the smell of the thing, and the fact that she can detect traces of other dogs; her friends and neighbours.
Compared to the average dog or, say, bat, the average human is a very visual creature. Of course, humans with visual impairments know that this is not the only way to be: our other senses of taste, touch, hearing, and smell are important and can be used when sight fails. Still, if the average dog’s world is ordered by smell and the average bat lives in a world generally perceived by what it hears, then the average human’s world is ordered by what we see. This is evident in the English language: we look into a topic, see what we can do about a problem, envision the future, illustrate concepts with examples, focus on an idea and give our view of an issue. Johnson describes the insights of early psychological studies of perception: “Human vision is holistic: our visual system automatically imposes structure on visual input and is wired to perceive whole shapes, figures and objects rather than disconnected edges, lines, and areas.”
Johnson’s book demonstrates with varied examples our inclination to perceive structure. Take the shapes below, for example. The stars on the left are likely to be perceived in horizontal rows, while those on the right are probably perceived as being laid out in vertical columns. In both cases, proximity leads to a sense of being in a group.
Staying with stars, look at the ones below and group them in whatever way feels natural:
Did you see four columns, each with two black stars and one white star? Or did you see three rows: four black stars in a row, then four white ones, then four black ones again? Here, generally, we perceive similar objects as being grouped, and so, Johnson suggests, we tend to see these stars as being in rows.
Our inclination to see structure, and in particular our tendency to see wholes rather than parts, is further illustrated with the example below, where most viewers see a circle rather than six curved lines.
If humans are predisposed to sensing visual structure as a means of understanding, then, Johnson argues, the inverse is also true: those trying to get others to understand should help their audience by providing structure. To achieve this, Johnson suggests creating visual hierarchy, which means arranging information so that information is divided into identifiable sections and subsections, which in turn are presented more or less prominently to signal the connections between them. So, for example, a main idea might be larger than a supporting point.
Application
The notion of visual hierarchy has various implications for teachers. At a fundamental level, the visual presentation of information helps students (or any audience) access its content. This is important for instructions, as shown in Slides E and F below:
It is also important for informative purposes. In presentation skills classes, I stress to students that visual structure can be used to help the audience navigate the presentation (also known as signposting) and to show the connections between areas of content (known as signalling). Compare the two examples below:
Slide H takes the content of Slide G and uses various features to structure the information. The topic of the slide is in bold and underlined; the key concepts, regular and irregular verbs are marked in bold italics; examples are in boxes; and aspects of form are made prominent with colour, underlining, and bold. I’m not saying this is perfect or to all tastes, but I’m confident that the information is clearer and more accessible than in Slide G.
In presentation skills classes, I’ve given students examples where visual hierarchy is absent (like in Slide G) and asked them to locate the differences in a slide where it is present (like Slide H). After analysing the differences together, I’ve given students dummy slides to edit, encouraging them to experiment with these visual features as well as text size, bullet points, and indentation. Finally, I’ve made these skills part of their assessment criteria.
The importance of cognitive empathy
When applying both of these insights to teaching, it is worth keeping a simple but powerful and easily forgotten idea in mind: what is clear to you is not necessarily clear to others. Avoiding this “curse of knowledge” is key to many teaching situations, and the design of visual aids is no different. From a visual perspective, as the designer, you will choose colours which work well for you. Remember also that you’re biased towards perceiving visual structure, and so the structure that you create will likely be very clear to you. You’ll also already know and understand the content of the visual aids. The design won’t be helping you understand the content, because you already know it.
None of this will necessarily be true of your students. Their colour vision might not match yours and environmental factors such as lighting, position, and medium have an impact. They might also perceive a different visual structure than you intended, or miss yours entirely. All of this might mean that the visual aid you have created to help them understand something might have the opposite effect.
In the medium to long term, it’s worth considering how you can work this into your CPD. There is a lot of material out there. It’s probably worth asking your employer if they have any resources or guidelines. That said, DAISY Learning offers free online courses on, for example, Accessible Word Documents and Accessible PowerPoint Presentations. The UK’s Royal National Institute for the Blind has straightforward guidance on creating accessible information using various media and many universities, such as the University of Oxford, give guidance on handout and presentation design.
In the short term, enlist critical friends. If you have time and a friendly colleague, enlist them as a critical friend. Show them your visual aid and ask what they take from it, without guiding them too much. Another option is simply to discuss these ideas with your students: ask them what works and doesn’t work for them, and solicit feedback on the visual aids you create.
References
Johnson, J. (2010). Designing with the mind in mind. Morgan Kaufman.
- Nickerson, C. (2023). The Trichromatic theory of colour vision, Simply Psychology, https://www.simplypsychology.org/what-is-the-trichromatic-theory-of-color-vision.html#Trichromatic-Theory-and-Opponent-Process-Theory
Jamie Emerson (MA, DELTA) has taught, designed, and managed English courses since 2012. He has written on whiteboards, created slides, and even designed a whole textbook around the UK, Europe, South America, and Asia. He has written for a variety of academic and trade publications and spoken at numerous conferences. He now works for Advance HE, a member-led charity for the Higher Education sector.