Structural Assessment of Learning Object

In this text, you find many fine examples of analyses of photographs in high school

textbooks that a student of mine conducted just after finishing her undergraduate

degree in biology and pedagogy. She presented this work at the annual conference of

the National Association for Research in Science Teaching. The paper was called

“Toward a Pedagogy of Photographs in High School Biology Textbooks.”

Photographs constitute a major aspect of high school science texts; a recent study

showed that there are about 17 photographs on every 20 pages of high school biology

textbooks. It is surprising then that a photograph (like a word) on its own does not mean

anything; it is only through recurrent use in similar situations that the relation of a word to

other words, a photograph to other photographs and words are established. For example,

one might ask, “What is the content of the photograph in Figure 1?”, which was taken

from a Brazilian high school biology textbook. “What is its meaning?” There are some

cows in the foreground, two trees and a fence further back. Then there is a field or

meadow before an assembly of trees, which may be seen as a “forest.” So what does it

mean? To find an answer, we have to seek recourse to the text from which we culled it the

photograph. The caption to the photograph talks about there being distinct biomes (“The

dividing line is a band with major vegetation that defines an ecotone”). Knowing this, we

can now return to the photograph and attempt to discover distinctness that would delimit

the different biomes that we are to find. Further reading of the caption then tells us

something about changes to greater density. The caption also talks about forest and

savanna, the later being a kind of field.

Once we find these descriptions, our gaze separates forest and field, disregards the

trees in the foreground, and isolates changes in density. What the text has done, therefore,

is not just described what there is in the image—if it was only a description of something

self-evident, it would not have been necessary. Rather, the text taught us what to look for

and how to parse a rather dense visual field. The text contributes to teaching us how to

detect biomes, ecotones, and how to distinguish them—though this particular photograph

Fig. 538. Two distinct biomes border on each other: the forest and the savanna. The later is a variety of field. The dividing line between both biomes is a band with higher density of vegetation and what identifies the ecotone.

Figure 1. Example of a photograph and caption from a Brazilian high school biology textbook in the context of teaching the concept “ecotone.”

makes the concept of ecotone appears in a simplistic way as a clearly identifiable

boundary. At the same time, the text in itself lacked something that the image provides.

Here, the figure authenticates what the text is about, the existence of biomes and

ecotones, and the borders that exist between biomes. In sum, the texts that are copresent

with the photograph provide the pedagogy for reading the photographic image, allowing

a small rather than a potentially infinite number of interpretations to be viable.

“What can students learn from textbooks when they in fact begin to study

photographs?” The question is salient particularly in the context present photograph

because of the difficulties of making distinctions between forest and savanna experienced

even by scientists. Thus, in one study Brazilian and French scientists attempted to decide

whether the forest was taking over the savanna or whether the savanna was taking over

the forest. A major problem to be resolved by the scientists he studied was just where to

locate the boundary between forest and savanna; another sociological study of ecologists

also showed the tremendous

collaborative work that went into deciding what constitutes the boundary between forest

and brush. Other studies documented similar difficulties experienced by amateur

birdwatchers as they attempted to identify birds even though they had the photographs

of their bird field guide directly in front of them. In practice, therefore, making a

distinction between forest and savanna appears much more difficult than the high school

textbook leads us to believe. As science educators, we therefore question,

what can and do photographs achieve when they are used in high school textbooks? What

purpose do photographs serve if they cannot guarantee that students identify their

equivalent in the natural world—after all, are science students not supposed to understand

and be able to explain the world around them?

Photographs and Texts: Principles of Analysis

We began this article by making the point that a photograph in and of itself means

little; it is full of “gratuitous” detail that allows many different ways of looking at and

interpreting it. This photographic detail provides a space that is continuous with our own

lived world, allowing readers to establish a link with the everyday world that surrounds

them. At the same time, the photograph provides few cultural codes (e.g., a line, letter, or

recognizable shapes) that could delimit its sense and meaning as intended by the author.

To control the range of possible meanings that a photograph can give rise to, authors use

captions and embed this photograph/caption combination in still further text (main text)

that together constrain the meaning a reader can make. In this section, we propose some

principles for the analysis of photographs in school science textbooks.

For the analysis of textbooks, we developed a scheme that articulates various semiotic

resources and the nature of their relations (Figure 5). We view all relations between the

different parts of a book (main text, figure, caption, and [sidebar] text box) as involving

double movements, each pair of entities mutually constituting one another and the

relation. Thus, the title prepares the reader for what is coming, and thereby organizes his

or her reading. At the same time, a title is not chosen arbitrarily, but has been motivated

by the content of the main text. The main text makes certain claims or seeks to explicate a

concept, which therefore motivates the use of a particular figure. The figure in turn

validates the claims made in the main text. Finally, the caption describes and teaches how

to read the figure (here photograph[s]) and the figure authenticates the caption text.

Figure 5. The framework that we developed for the analysis of inscriptions that accompany scientific texts in general and for photographs in particular.

In the analyses below, we are centrally concerned with the relationship between

photograph (figure) and caption, and their integration with the main text. This integration

is achieved not only through the co-thematic nature of figure and caption but also

through an index by means of which readers are referred from a particular place in the

main text to figure and caption, which constitute a different genre. The caption is an

essential part of the inscription that tells the reader what look for in the photograph and

therefore how to read and understand it. The photographs are associated with a text that

explains the phenomenon. Thus, photograph and text together form the written correlate

of a demonstration; they constitute a particular form of pedagogy, though our informally

acquired information in another study shows that most students disattend to anything

other than the main text. If this is the case, then important concepts and information

should be placed in the main text, with the appropriate reference to the inscription that

would help the reader to make sense of the phenomenon under scrutiny.

PHOTOGRAPHS IN BRAZILIAN HIGH SCHOOL BIOLOGY TEXTBOOKS

In our analysis of the pedagogical role of photographs in high school biology

textbooks, two themes emerged: there are different functions that a photograph/caption

has with respect to the main text and there are different ways in which the photographs

and the texts are structured, with implications for the interpretation of these inscriptions

in the textbook. In the following sections, we describe and provide evidence for these two

themes.

Functions of Photographs

In the ecology sections of the four Brazilian biology textbooks, all 124 photographs

could be classified as full-filling one of four functions (roles), which arise from the

relation of photograph/caption to the main text. However, we also include in this

classification those photographs that accompanied other inscriptions, as for example,

maps. Series of or pairs of photographs were considered one single inscription in this

classification. Therefore, the total of inscriptions classified in the four categories are

N=148.

The categories we identified are: decorative (n = 8 [5.4%]), illustrative (n = 52

[35.1%]), explanatory (n = 42 [28.4%]), and complementary function (n = 46 [31.1%]).

These functions—and therefore our categorization—largely arise from the interpretation

Figure 6. Example of a decorative photograph; there was no caption that accompanied it.

of caption, the text co-deployed and directly associated with each photograph. These

functions also roughly define a hierarchy of increasing informational value (explaining a

concept does more than simply illustrating a concept) and those with higher information

value usually also do what the photographs of lesser informational value do. We

exemplify and discuss each of these roles.

Decorative Function

A small number of photographs were classified as decorative. These photographs

were not referred to in the main text, did not include a caption, and usually appeared at

the beginning of a unit, chapter, or section of text. Figure 6, for instance, appeared on the

opening page of a section on “energy and matter in the biosphere.” This photograph does

not include a caption; there is no reference from the opening of the main text to the

photograph. How the photograph functions in relation to other texts deployed (its

intertextuality) requires analysis and does not “jump out” at the non-initiate. At the

outset, it is a colorful plate from which relevant figure and ground have to be separated.

Prior exposure to cultural categories allows readers of a certain age—a one- or two-year

old may not perceptually differentiate what an adult sees as leaf or caterpillar—to

identify a caterpillar on a leaf. That is, in the absence of a text inscribed in the book with

reference to the photograph, the reader has to bring existing understanding as the intertext

in reference to which the photograph becomes salient figure. What is the role of this

photograph at this place in the book? What can a student learn by looking at or analyzing

(studying) the photograph? A photograph can be viewed in many different ways. To

understand what this photograph is intended to show in this place, a reader may search

for clues in nearby texts, such as the title of the unit. Assuming that the text is not only

codeployed but also cothematic with the photograph, a reader seeks to relate individual

words “energy,” “matter,” or “biosphere” to the photograph. A somewhat initiated reader

may see the caterpillar nibbling away on or “eating” the leaf; but we insist that “nibbling”

as a process is not available to readers, it has to be inferred based on extra-textual

experience. However, not until a reader knows the relationship between “eating” and

“energy” household of animals can s/he establish a connection with (one part of) the unit

title. At the same time, the leaf has to be understood as matter rather than as an organism,

and both the caterpillar and the leaf have to be seen as aspects of “biosphere” before the

relation of this photograph to the unit title can be established. Students, however, are not

likely to bring this understanding necessary for establishing these relationships between

unit title and photograph. In fact, the purpose of the unit is to develop the understanding

necessary to deconstruct the relationship between photograph and title.

This initial analysis shows how, for the initiate reader, unit title and photograph can

be seen in a mutually constitutive relation expressed in Figure 5. The word “energy”

makes a reading of “caterpillar eating leaf” a reasonable reading of the photograph,

which, in turn, establishes a concrete instance of the relationship between biosphere and

“matter and energy,” concepts usually introduced in the physical sciences. However,

because students do not bring the interpretive resources required for the type of analysis

provided and because of the lack of a text that could guide students in their analysis of

the image, we categorized such photographs as decorative. They introduce color, may

provide for certain aesthetics, but lack informational function for the individual who does

not already know what the subsequent text is intended to teach.

Illustrative Function

Photographs included in this category include a caption that names or describes what

the reader is to see in the photograph but the caption does not provide additional

information to the main text. Such photograph-caption ensembles constitute a visual

resource for the reader in the sense that a concrete specimen of a class or concept is

depicted (e.g., Figure 7).

Fig. 4.3 Photograph of plants of aguapé in blossom.

Figure 7. An example of an illustrative photograph.

This photograph gives the reader a visual representation of the species mentioned in

the main text (aguapé), but this is not an essential piece of information for the reader

relative to the subject matter treated in the text. In the present case, the subject matter is

the introduction of certain species in biomes, exemplified by the introduction of aguapé

in hot regions. “Aguapé” and “hot regions” are special instances of the more general

concepts of plant and biome.

The photograph illustrates the particular plant but does not show “introduction” that

causes changes in the ecosystem. To show the effect of “introduction” of a plant, a

minimum of multiple photographs are required that show some difference that can be

noted as a difference before it, according to Bateson (1972), can function as

“information.” That is, if there is not a difference that makes a difference, we cannot

speak of information at all. Therefore, the very concept taught in the text is absent from

the photograph: it does not exist as information in the image. The visual information

possibly provided does not alter the understanding of the subject matter, that is, the

photograph does not show the phenomenon treated in the text, but provides a visual

illustration of a plant that was only referred to in the text as an example of a species

which introduction caused changes in the ecosystem. The reader still is able to understand

the concept of ecological disequilibrium treated in the text without the information

provided by this photograph and the caption.

There were several cases (n = 29) of illustrative photographs that were not associated

with a (part of a) caption. Such photographs, a special case of photographs without

caption, appeared together with “maps,” the dominant aspect of the inscription (Figure 8).

Here, several photographs were co-deployed with the map but were not described or

explained in the caption. One might therefore think that the photographs are decorative,

especially because the caption of the inscription is related with the map. However, there

is an important link between photographs and map: the color scheme of the legend relates

photographs, presenting single (paradigmatic) instances of different landscapes, and

regions. If map and photographs are interpreted as being cothematic, by virtue of

appearing in the same plate, the different genres can be read as linked via the concept of

biomes: “distribution of different biomes” and concrete instances of individual biomes. In

this situation, there is one photograph for each biome but, in the presence of six images, a

contrast is provided between what may be prototypical examples for each biome. The

presence of only one example does not allow students to learn what characterizes each

biome or more poignantly, how to distinguish one biome from another in more

problematic cases near the border of the category. (See Lakoff [1987] on examples of a

category that are nearer the center, and therefore more prototypical for a category versus

those that are nearer the peripheries of two categories, and therefore more problematic in

their assignment to one or the other.) But the presence of six prototypes, given learners

attend to appropriate aspects of the landscapes depicted, may allow the recognition of

some global distinctions between these biomes. Nevertheless, some of the very features

that distinguish these biomes, the amount of water available, temperature, and other

Fig. 7 Large biomes of Earth.

Figure 8. An example of a special case of illustrative photographs, each ecozone identified in the map exemplified by one member of the category.

physical and biological information, is not accessible by students through the analysis of

the photographs.

Explanatory Function

This category includes photographs with captions that provide an explanation of or a

classification of what is represented in the photographs. The captions do not only name

the object or phenomenon in the photograph, but also add information about this object or

phenomenon. Take the example of Figure 9. In the first part of the caption we can read

“Aspect of a forest.” With this information, readers are guided in what to look for in the

photograph, a forest. That is, what we see are not just a group of trees along a river but

part of a larger whole. This information provided by the caption is important in helping

the reader to make sense of what can be seen in the photograph, however, this

Fig. 84.1- Aspect of a forest: climax community.

Figure 9. Example of an explanatory photograph. The words “climax community” provide a frame that allows the reader to establish a connection between the figure and the main text.

information is not enough to guide the reader to establish relations between the

photograph and the subject matter treated in the main text.

The index presented in the main text and replicated in the caption allows the reader to

connect figure and text. However the reader is not able without further information to

appropriately relate the “forest” in the photograph with the concept of “ecological

successions” that is the corresponding topic of the main text. Thus, if this were the only

information provided in the caption, the photograph would function as an illustration of a

forest, because somewhere in the main text the forest was mentioned. It is the second part

of the caption that provides the information necessary to interpret the forest in the

photograph as “something else,” which allows the reader to explicitly relate the figure

and the text. These two words, “climax community,” represent an entire different

perspective in the way in which the reader contextualizes the photograph and relates it to

the main text.

The photograph not only represents a forest, but also is marked as an example of a

climax community. Textual marks are not neutral but invite making salient some things

to the exclusion of all the others that could be made salient (Derrida, 2001). That is,

marked terms encourage readers to associate the characteristics of a climax community

described in the main text with what they see in the photograph. In this sense, this caption

not only classifies the forest as a climax community, but also provides an explanation

about how to interpret and relate the photograph with the main text.

At the same time, because this is a single photograph, the concept of succession is not

available to readers, which would require several photographs showing the same physical

location but with varying cover corresponding to varying stages in the ecological

succession of the area. Similarly, the single photograph does not allow the initiate reader

to learn how to distinguish climax forest from non-climax forest, or between the climax

forest for different forms successions such as those that end in maple-beech forest

(Northeastern US, Eastern Canada) or those that end in coniferous forests (Canadian

shield, Newfoundland). Both types of forest are examples of climax forest but are very

different in the way that they appear to the eye.

Complementary Function

Photographs in this category are associated with captions that add new information

about the subject matter treated in the main text. This information is not only new, but it

is also an important information, never mentioned before in the main text, and that helps

readers to further understand the biological concept that is being taught. Figure 10, for

example, presents two fishes against a black background. The title of the section of the

text where this figure is inserted in is “Influence of light in the marine ambient,” and in

the main text we can read about the distribution of species in the ocean according to the

presence or absence of light. In the last paragraph the text presents some characteristics

of fishes and other animals that live in the abyssal zone. Then the text refers the reader to

the figure.

The text begins by providing a name and articulating it as an example of an “abyssal

fish.” Inherently, the statement “linofrino, an example of an abyssal fish” requires the

cultural competence of associating the name with the image, even though there is no

specific index linking the name with the fish—parents reading to their preschool children

might place their finger on the image and say, “linofrino.” The remainder of the caption

Fig. 86.6- Linofrino, an example of an abyssal fish, about 5 cm long, that lives at a depth of 1400 m in the ocean. The abyssal fishes usually are small and dart-like and have sensitive eyes.

Figure 10. Example of complementary plate: the caption makes factual statements not available in the main text.

provides propositions with content not made available in the main text, and therefore

constitutes new and relevant content. We therefore classify this photograph-caption

ensemble as complementary.

The caption in this case provides information about what can be seen in the

photograph, that is, characteristics of the abyssal fishes represented. The caption also

adds new information, not directly related to the two fishes, but, rather, associated with

the concept of abyssal fish treated in the text. Therefore, this plate constitutes a

“complement” to the main text. The complementary photograph/caption thus presupposes

continuity in the reading process, as readers iterate their reading between main text and

plate. They are able to make sense of the concept presented only through the reading of

all the information contained in these three elements. If the information in the caption is

new and important, we therefore have to ask why this information is in the caption

instead of in the main text—unless photographs/caption are regarded by students and

teachers integral parts of the “material to be studied.”

Structures of Co-Deploying Photographs and Texts

Our analysis reveals considerable variation between and within textbooks in how the

co-deployment of photographs and texts is structured. The structural elements and the

relation between them are diverse among the selected textbooks and even within the same

book. The variations include, for example, where the reference to a photograph occurs in

the main text, the distribution and arrangement of photographs on the page, and the co-

deployment of multiple photographs for teaching a particular concept. These structural

elements, undoubtedly, provide different resources for integrating co-deployed and co-

thematic but non-co-generic text.

Indexical Reference

Photographs represent a different genre than text. They are two-dimensional

arrangements of colored or areas, which, because of our prior experience in a three-

dimensional world, can be decoded to provide additional information about depth. Color,

areas covering other areas, relative size of known objects and so forth provide resources

for reading that are deployed as the eyes scan the image according to the reader’s

preference. Verbal texts, on the other hand, are linear, conventionally (in Euro-centric

cultures) requiring the eye to move from left to right and jumping, at the end of a line,

downward to the left of the subsequent line. Because of the different requirements for

reading verbal text and images, the latter cannot be placed at the point in the text that is

directly pertinent (co-thematic). The link between the text (word, sentence, or paragraph)

and the photograph that appears somewhere else on the same or different page is

established via an indexical reference usually as a string of letters and numbers in the

form “Figure 1.2,” “Fig. 2,” or “see Fig. 3.4.” A copy of this index is also found in the

caption of the figure that the index is designed to direct the reader. Here, the indexical

function is achieved by duplicating a string in the main text and in caption. Whenever the

string appears in the main text, the reader is referred to the photograph/caption that

features the same (co-generic) string. That is, the relationship and “placement” of a

photograph with respect to the dominant text is achieved by means of a string that

appears twice but in different locations on the page or in the book. The role of the string

is salient when we consider that a similar relationship does not suggest how to link

caption and photograph. Here physical proximity is used to suggest that the text directly

bears on something in the image. How this bearing might be achieved still remains

undetermined at this point. (We discuss the nature of this relationship and how the reader

enacts it in the next section.)

Two textbooks consistently used the same way of referencing photographs/captions

either placing the indexical reference at the end of a paragraph in which the co-thematic

concept appeared or not using an indexical reference at all. The two other books each

employed three different ways in placing the indexical reference in the main text. Thus,

the indexical reference was placed either at the end of the paragraph or directly with the

co-thematic word or sentence or was absent altogether.

When the indexical reference is placed immediately after the word or after/within the

sentence that is co-thematic with the photograph/caption, a direct link is established

between what are on the surface different (because non-co-generic) representations. On

the other hand, if the indexical reference is placed at the end of a paragraph where there

are potentially multiple concepts presented, the link is no longer direct. One may consider

the index “misplaced,” because the photograph/caption is not evoked simultaneously with

the verbal texts. There is the potential that misplaced indexical reference in books

interferes with sense-making processes in ways similar to misplaced gestural indexical

reference that make it difficult to learn from lectures. Finally, when there is no indexical

reference at all, it is totally up to the reader to see whether

there is any relation at all between a photograph/caption on the main text on the same

particular page.

Figure 11 exemplifies a “misplaced” indexical reference. In this situation, because the

index is placed in the end of the paragraph, the reader may associate the photograph more

spontaneously with the last phrase or statement—particularly in those textbooks where

the indexical referencing changes. The photographs represent (1) a burned area and (2) an

a. b. Factors of Ecological Disequilibrium Changes in the structure of ecosystems Deforestation

One of the most important ecological problems today

is the destruction of forests, as these occur with the Atlantic Forest in Brazil. Today less than 10% of this forest type remains compared to the period of colonization. Each year, the world loses forest areas; forests are cut or burned, leading to serious soil da mage and causing a tmosphe ric pollution. Furthermore, many species become extinct, thereby decreasing “global biodiversity,” as scientists call the large variety of living forms produced by biological evolution. (Fig 4.1) Figure 4.1 Deforestation is a common way of

damaging terrestrial ecosystems. (A) Photograph of burned area in the Amazonian Forest, used to create pasture areas for livestock farming. The fire kills the microorganisms that fertilize the soil, and the rains wash the nutrients away since the vegetal coverage was destroyed. (B) Photograph of regions of soil erosion provoked by the elimination of the forests.

Figure 11. Example of an inscription with a ‘misplaced’ indexical reference. a. Main text. b. Photograph and caption referred to at the end of the corresponding paragraph in the main text.

area of erosion of the soil. Although the main text mentions burning and cutting the trees

as ways of causing deforestation, the index to the photograph is physically far away from

the specific phrase where deforestation is mentioned.

To associate the photographs with the main text, the reader needs to go back to the

middle of the paragraph and find the specific phrase that refers to deforestation. Then, the

reader must go back and forth in his or her attempt to read the text. This reading requires

the reader to work from the text and the photographs, at the same time “reading” and

“seeing” to make sense of the biological concept presented.

Figure 12 presents an example of an inscription with no index in the main text. This

inscription presents two photographs: the photograph in the left shows a river with

abundant vegetation in both its banks, and the photograph in the right shows a desert. The

caption reads, “The amount of water and the richness of life are interdependent.” Because

the main text does not contain an indexical reference, we can only try to establish a

Figure 10 Quantity of water and richness of life are interdependent.

Figure 12. Example of a photograph without any indexical reference in the main text.

relation between text and photographs, the relationship of the photograph to the main text

can only subsequent to reading the entire main text section and the photograph/captions.

When the photographs appear alongside one another, the composition highlights the

importance of water for the existence of life. Thus, through a comparison of both

photographs, the reader is supposed to associate life and water in the way intimated by

the caption. However, this is just one way to interpret this inscription, and many other

interpretations can also emerge since there are no explicit directions or enough

information in the main text or caption to help the reader to make sense of this.

The situation becomes even more difficult when the photograph is physically placed

far away (several pages) from the corresponding text. In this situation, the reader will

find him- or herself completely “lost in the book,” since s/he will not find any direct

association between the text and the figure, because of the absence of the index.

Furthermore, the reader will have difficulty to manage the book pages to associate the

figure with the text, because of the disposition of the inscription many pages after the

one in which the text was placed. At this point, the figures even

Fig. 581. At left, the vice-king butterfly. At right, the monarch butterfly, which has repugnant taste for the birds. Because of the similarity between them, many birds reject the first one, which benefits itself from mimicry.

Figure 13. Example of photographs arranged in pair, which allows the reader to look for variant and invariant properties.

though associated with captions, may serve decorative rather than higher functions in the

text.

Single and Multiple Photographs

The arrangement of the visual document within the text mediates our ability to see the

phenomenon represented in the photograph, that is, part of our interpretation of the

photograph depends on the way in which the figure is organized, and how the photograph

relates to other photographs. One way in which a photograph can be related to others is as

part of a pair or a series. Photographs arranged in series allow the reader to progressive

focusing his or her attention on the concept examined by the text. Consider for instance

Figure 13. At a first glance, the reader may see these two photographs as presenting the

same butterfly, due to the enormous similarity between the species represented in both

photographs. However, the caption cautions us that the photograph at right presents one

species of butterfly, and that, actually, the butterfly in the photograph at left only seems

to be the same species as the earliest, what constitutes the phenomenon called mimicry.

The authentication of the phenomenon of mimicry is presented in the main text is

possible due to the arrangement of the photographs in a pair, which allows the significant

differences become evident trough the process of comparison. Nevertheless, a

Fig. 3.10 (A) Photograph of a Hibiscus plant covered by the cipo-chumbo. In the detail, in higher magnification, the relation between the parasite and the stem of the host plant.

Figure 14. Example of multiple photographs, one being constituted by the text as presenting the detail of the other.

comparison between the two photographs is not enough to give the images meaning. The

caption is also necessary to guide the reader to look for the differences—instead of the

similarities that are more evident in this case—between the two photographs, to

recognize the phenomenon of mimicry. Similarly, in a series of photographs, as for

example in Figure 4 (p. 14), the process of authentication of the phenomenon presented in

the text depends on the reader’s perception of the differences between the photographs. In

making the photographs part of a series, the uncertainty about the meaning is reduced,

and the reader, then, is able to eliminate everything that does not change, in a process that

progressively highlights what there is to look at and make sense of in this figure.

Another way in which a photograph can be related to others is when it presents the

same object as another photograph, but in a different way, which allows both

photographs to become complementary to each other (Figure 14). The first photograph

shows the plant in a broader view, while the second photograph focuses on a specific part

of the same plant. Together, the two photographs allow the reader to identify the plant in

the way in which it could appear in nature, and, at the same time, pay attention to the

specific detail relevant to the concept presented by the main text. Both photographs,

therefore, function as complementary to one another, the second photograph becoming

Fig. 83.1- Epiphyte plant

Figure 15. Example of photograph that carries too much information and it is unclear which of the many plant is the “epiphyte plant.”

“part” of the first one, as a detail in higher magnitude, that provides the reader a better

visualization of the phenomenon treated in the main text. Multiple photographs,

therefore, allow the reader to make external comparisons and therefore visualize the

phenomenon presented by the main text. A single photograph, however, can only provide

internal comparisons, leading the reader to find the relevant details in the photograph on

his or her own. Thus, in the process of interpretation of single photographs, the directions

in the caption and other indications, as for example, letters or arrows added over the

photograph itself, are important resources that guide the reader’s attention to the “right”

detail.

For example, Figure 15 fails to demonstrate the object that it should represent

according to the caption. The caption reads “Epiphyte plant,” but there are many different

plants without distinction that allows him or her to identify the epiphyte plant. Even

though there is a tree placed in the center of the photograph, which may draw the reader’s

attention, it is not possible to identify the epiphyte plant, unless the reader already knows

what to look for. That is, the reader has to know what an epiphyte plant looks like in

order to find it in this photograph. The difficulty, in this case, is related to the “framing”

(Bastide, 1990) of photographs, that is, the process by which the reader narrows the

Figure 3.9 Photograph of the interior of a tropical forest, showing epiphyte plants, associated with host trees by inquilinism.

Figure 16. In this photograph is possible to identity the epiphyte plants, even though it still present other plants in the background.

perceptual field to eliminate as many irrelevant elements as possible from the background

while trying to show the object as a whole.

The aim in framing photographs therefore has to be making sure that it contains the

least information possible, for fear of confusing the meaning. The details in the

background seem to carry no relevant information at all, despite their function of making

the photograph more “natural,” because it can be perceived as a depiction of a particular

piece of nature. However, the effect of realism does not depend on the complete

reproduction of the world, but on the viewer’s perception of the narrative and perceptual

order. Therefore, it could be more appropriate, at least in certain situations, to present an

object against a neutral background, even if it compromises the ‘reality’ of the photograph

as a depiction of the real world. Compare Figure 15 to Figure 16, which also represents an

epiphyte plant. The relevant element in this photograph—the epiphyte plant—is clearly

distinct from the background, even though the photograph still presents other plants. The

epiphyte plant is not only in the center of the photograph but also the only object that the

reader can clearly distinguish. The figure was framed to show just

this particular plant, and all other objects are out of focus, becoming part of the irrelevant

details in the background.

Fig. 78.2- The dead organic matter is decomposed by bacteria and fungus, as we can see in this photograph of a leaf laying down in the floor for months, and in final process of decomposition.

Figure 17. The black background highlights the object represented in the photograph.

Sometimes a completely black background is a better alternative for highlighting the

phenomenon or object in the photograph (Figure 17). The reader is immediately directed

to whatever is shown against the black background that is easily identifiable as irrelevant.

Thus, the arrangement of the photographs in the books, as well as the intrinsic

characteristics of the photographs themselves, have an impact on the process of

interpretation of the figures, and consequently, in reader’s ability to relate the photograph

with caption and main text.