“A true photograph need not be explained, nor can it be contained in words.”
Ansel Adams

A picture is worth a thousand words. As someone who has practiced the art of photography for most of his life, this phrase has always rung true.  The phrase seems to have had its origin in US advertising in the early 20^th center. (The Phrase Finder, retrieved June 25, 2019, from https://www.phrases.org.uk/meanings/a-picture-is-worth-a-thousand-words.html) While it is certainly possible to learn without images, ask the 63,357 K-12 blind students in the US, (National Federation of the Blind, Blindness Statistics, retrieved June 25, 2019, from https://nfb.org/resources/blindness-statistics) image use is quite prevalent in education.

I don’t know many biology teachers that teach the structure of a eukaryotic cell without using a picture like the following one.

Not only does this diagram display the components of a cell, but it also helps to establish a relationship between the different parts of the cell. In the textbook Concepts of Biology, the introduction to the structure-function of eukaryotic cells is 14 pages long.  There are 16 images and 4486 words on 14 pages.  That works out to about 320 words and one image per page.

The ratio of text to images in textbooks changes as students’ progress from kindergarten to college. The structure of the college textbook is different from primary school readers.  For example, in the Jack and Jill or Little Dog Spot readers, the whole page is a picture with a maybe seven words (Jack and Jill went up the hill).  While I don’t think a cell biology textbook written like a Jack and Jill book would be a good idea.  Can you imagine how long a college textbook would be if each page were a full-page image with a single sentence like, “eukaryotic cells contain a membrane-bound nucleus?”

While textbooks composed primarily of images will probably not work, I do wonder if we make proper use of images in textbooks.  One of the most common complaints, besides cost, I hear from students is that textbooks are boring, too long, and hard to read.  While the central point of a textbook should be as a teaching tool not merely as a download of facts, we also need to remember that learning to extract information from text is essential.  There are times when books of exclusively just text are necessary, even essential. I don’t see my Shakespearean literature class having worked without reading the plays. That said I do wonder if textbooks should not only include more images but use the images as a central teaching tool rather than just support for text after all image use is a core part of our mental processes.

Images have been with us for longer than written language.  Some of the earliest examples of human-created images are cave paintings, like the paintings found in the Leang Timpuseng cave on the island of Sulawesi, Indonesia.  Scientists have dated the paintings in this cave to at least 35,400 years old.  While they are not as well-known as the paintings in France’s Chauvet Caves, they are older than Chauvet (32,000 – 28,000 years old) making them possibly the earliest cave painting in the world.

Written language was developed around 5200 years ago in the form of the cuneiform script by the Mesopotamians.  The cuneiform script has a direct linkage to images carved in small clay tablets.  The earliest writing was to take these clay tablets and press them into a sheet of clay, “recording the image.”  These images evolved into the symbols of the cuneiform script. In addition to the fact that humans have been using imagery for 10s of thousands of years longer than written language, there is also evidence that images are more effective for learning than text.

One of the ideas behind images being better learning aids, then the text is the theory of dual-coding.  Simply the theory of dual-coding is that images activate two memory centers.  A text-based system and a separate image-based system.  While text by itself only activates a text-based system.  It is also possible that this dual-coding system would work with the other senses, touch, smell, and taste. In education, dual-coding gives the learner twice the number of memory locations for recall.

Beyond cognitive mechanisms like dual-coding, there is also the idea of visual langue. “Visual language is defined as the tight integration of words and visual elements and as having characteristics that distinguish it from natural languages as a separate communication tool as well as a distinctive subject of research.” (Visual Language and Converging Technologies in the Next 10-15 Years (and Beyond)) Infographics are an example of visual language.  Additionally, the paper Visual Language and Converging Technologies in the Next 10-15 Years (and Beyond), says that visual communication increases information transfer. “For example, improvements in human performance from 23 to 89% have been obtained by using integrated visual-verbal “stand-alone” diagrams.”

The ideas of dual-coding, coupled with visual language, suggest that textbooks should include more images.  Additionally, these images should be integrated tightly with the text and viewed as a central component of the learning process. Authors should not consider Images as secondary to the text but as an essential learning component on their own.

However, like so many other aspects of educational research while there is research stating that textbooks are not useful learning tools.  It is not clear if this failure is because textbooks are inherently ineffective learning tools or because of factors other than learning drive textbook design.  As I have said repeatedly, we desperately need more research into what makes an effective textbook.  In the meantime, maybe we should add a couple of pictures.

Thanks for Listing to my Musings
The Teaching Cyborg