The Qualities of Images
Consideration of images—their strengths and weakness as a communication medium and the demands they place on learners—rounds out our discussion of traditional fixed instructional media. Still images are a longstanding component of instruction, but one that has usually been relegated to a lesser role. However, images' increasing cultural prevalence through television, magazines, movies, and, of course, computers, are making them more important in classrooms.
Advantages of images. The major point of contrast between still images and language is that language communicates linearly and sequentially, whereas images communicate everything at once. Images offer immediacy and they capture the entirety of a view. Novelist Mark Helprin expresses a similar viewpoint through one of his characters:
Paintings . . . (are) so easily apprehensible. They're present all at once, unlike music, or language, with which you can lie to the common man merely because he may not remember what has just been and cannot know what is coming. . . . Painting is tranquil and appeals directly to heart and soul." (Helprin, 1991, p. 284)
This quote highlights another important advantage of images: their ability to convey emotion and feeling more directly than text can. Images' directness and ability to present all their information simultaneously makes them excellent choices for portraying mood, capturing relationships, making comparisons, and understanding parts versus wholes. Finally, representational images don't require decoding because they convey information literally. Viewers need not follow a particular path when looking at the elements in an image; they can choose the order of inspection.
Limitations of images. Although images can be used to simplify complex information (e.g., a visual display of data or a diagram of the water cycle), sometimes they are governed by conventions that can be quite complex, requiring training and practice to interpret. Further, images are not ideal for conveying conceptual, philosophical, and abstract information—anything below the surface or above the instance. Their ability to explain, clarify, ask questions, speculate, negate, or convey inner thoughts and emotion is inferior to language in many cases (Stephens, 1998). Of course, there are exceptions. Think about how powerfully expressive pictures of the American flag can be: the flag raised at Iwo Jima, the flag burned in protest, the flag brandished by an Olympian, or the flag flying over the rubble of the World Trade Towers.
Images also make unique demands on the nervous system. Let's touch briefly on some of the different processes involved in understanding images to highlight barriers some learners may face.
Interpreting images requires visual acuity and the ability to recognize the parts in relation to each other-in size, depth, movement, and many other ways. Because different visual features are processed in different parts of the visual system, some aspects of an image can be accessible to an observer, while others may not be.
For example, studies have shown that particular brain lesions can impair the ability to analyze parts of a picture, but not the ability to understand the picture's gestalt—the overall idea it’s communicating. Other damage can disrupt the ability to perceive shape, but not color (Zeki, 1999). These specific deficits are not unlike those we observed with spoken language, as when a person with a particular language disorder might have difficulty understanding word meanings but can interpret emotional tone or vice versa. These insights make it clear that images, like other media, are processed in parallel by multiple modules within recognition networks.
Understanding an image requires the analysis of parts and wholes. Individuals create viewing strategies according to their own purposes and the nature of the image itself. Images used to convey complicated concepts make additional demands, requiring skilled interpretation based on the knowledge of graphic conventions, such as placing the most important elements at the center of the page, or organizing the various elements in ways that draw the eye and encourage it to linger.
Just as learners can be distracted when processing text, they can mistakenly focus on an image's unimportant elements. Strategic networks help viewers determine what is important and focus their attention where it is most productive. Skilled viewers are much more successful because they apply top-down processing: Their inspection is more firmly anchored to the meaning or knowledge they seek, and they are skilled at tying what they see to what they already know.
Affect is also crucial to deciding the important elements of images and understanding them. A viewer's individual emotional preoccupations may steer him away from his intended viewing strategy or prevent him from receiving the message the image's creator intended. On the other hand, a lack of emotional engagement may prevent a viewer from looking closely at an image or may block the viewer's comprehension of the image's emotional content. However, affect is not always negative. Positive affective engagement may feed an individual's interest—and persistence—in working with images.
Compared to speech and text, images offer a partially overlapping but unique set of advantages and limitations for teachers and learners. Images share the directness and emotive power of spoken language and the permanence of text. Unlike either of these media, they present everything at once rather than sequentially, giving viewers the opportunity to examine the information in images in their own preferred sequence. Barriers to understanding images can occur in any or all brain networks and include among other things, inability to see the images, difficulty with systematic examination and interpretation, or simple lack of interest. Considering the purpose of a particular lesson and the strengths and weaknesses of a student can help teachers evaluate the appropriateness of using images for teaching and student expression.
