Pragmatic Analysis

This analysis focused on appropriateness of diagrams for their intended purpose, and for specific target audience. The analysis has three principles.

Principle 7: Purpose compatibility

Textual information should be provided to explain the purpose of each diagram. In addition, each diagram should have an appropriate amount of information needed to achieve its intended purpose.

Diagrams 1, 3, 5, 7, 8, 11, 13, 15a, 16, 18, 21b and 24 have captions explaining what each diagram represents, while diagrams 9, 10, 14b, 20 and 21a are placed near textual information clearly

explaining the purpose of each diagram. These diagrams do not violate this principle. On the other hand, Diagrams 2, 4, 6, 12, 14a, 17, 19, 22a, 22b and 23 have neither captions nor textual information stating what each diagram represents. However, the diagrams are placed under text explaining phases of the Moon. As a result, viewers can easily link diagram with phases of the Moon. These diagrams, too, do not violate this principle.

Diagram 15b is the only diagram which is considered to violate this principle. This diagram has no heading and/or textual information explaining what the diagram shows. The diagram is one of two illustrating information about the Earth-Moon-Sun system. Both diagrams are placed below text dealing with the Earth-Moon-Sun system (but not necessarily phases of the Moon). No textual information explains what each diagram illustrates. As a result, it could be difficult to know what each diagram illustrates.

Three diagrams lack information that would make them achieve their intended purposes. Diagram 11 consists of the Earth, the Moon in four positions around the Earth, and corresponding four phases of the Moon. The caption below the diagram says ―As the Moon travels around the Earth; we can see different amounts of its sunlit face‖. However, the Sun is not shown in the diagram. As a result, it becomes difficult to see the ‗sunlit face‘ of the Moon from this diagram. Diagram 12 consists of the Sun‘s rays, the Earth, and phases of the Moon placed around the Earth, (but not the Moon as seen from space). Text above the diagram says that ―the changing shape of the Moon is called the phases of the Moon‖, followed by a caption which says ―Here‘s how it happens‖. The caption suggests that the diagram is intended to explain the cause of moon phases. The diagram would achieve this purpose only if it illustrated the Moon as seen from space. Thus, information in the diagram is not enough to achieve the intended purpose.

Diagram 13 consists of the Sun‘s rays, the Earth, and eight phases of the Moon placed around the Earth. The diagram is placed below an activity instructing learners to ―use the diagram … to identify and name the phases of the Moon as you move (the Moon) around the Earth‖. The diagram cannot fully achieve this purpose because of the following two problems. First, Waning Gibbous and Waning Crescent shapes have been incorrectly used to represent Waxing Gibbous and Waxing Crescent phases. As a result, learners using this diagram cannot find appropriate shapes for Waxing Gibbous and Waxing Crescent in the diagram. Secondly, an inappropriate label ‗gibbous moon‘ has been used to label Waxing Gibbous and Waning Gibbous, and the label ‗crescent moon‘ has been used for Waxing Crescent and Waning Crescent. For this reason, learners cannot identify appropriate names from the diagram.

Principle 8: Textual compatibility

If diagrams are intended to illustrate concepts described in text, there must be correspondence between the diagram and the textual content.

No contradictions have been found between the diagrams and the textual information. In addition, the diagrams and text used the same terminology (whenever textual information was provided). As a result, the principle has not been violated.

Principle 9: Audience compatibility

Diagrams should be designed to comply with culture and context of intended viewers. For example, information should be presented from left to right and from top to bottom in accordance with the reading convention used in schools. Also, a diagram designed for viewers in the southern hemisphere should illustrate moon phases as they appear in this hemisphere.

Fifteen diagrams illustrate phases of the Moon as seen from the northern hemisphere, despite the fact that the diagrams are intended for use in the southern hemisphere. Thus the principle has been violated in fifteen diagrams. This observation corroborates results obtained by Trundle et al. (2008) who found that diagrams in two story books designed for children living in the northern hemisphere illustrated the sequence of moon phases as seen from the southern hemisphere.

Principle 9 dictates that information on diagrams should be presented from left to right and from top to bottom in accordance with reading culture used in school. Diagrams 12 and 16 illustrate the Sun shining from the right-hand side of the page, requiring viewers pay attention to components on the right-hand side before components on the left-hand side. This, however, has nothing to do with reading but everything to do with ability to mentally change one‘s orientation on the page (i.e. it is a spatial ability issue). As a result, the diagrams are considered to have not violated this principle.

6.3.6 Summary

The curriculum requires Intermediate Phase learners to know the sequence of moon phases and to understand the cause of these phases. In addition, the curriculum requires Senior Phase learners to know that the movement of the Moon relative to the Earth and the Sun causes moon phases. On the basis of these requirements, publishers present information dealing with phases of the Moon in books intended for the Intermediate and Senior Phases. The discussion presented in this chapter shows that several diagrams have design problems that might hinder understanding of this information. Table 6.2 summarises design weaknesses found in diagrams analysed in this study. The table shows that only one diagram violated none of the principles used in this study. Three diagrams violated syntactic principles, meaning that viewers might encounter problems when trying to perceive information illustrated in these diagrams. In addition, 22 diagrams violated at least one of the semantic principles, suggesting that students might learn inaccurate information if teachers are not careful when using the diagrams. Furthermore, 19 diagrams violate at least one of the pragmatic principles, suggesting that these diagrams did not comply with the context of the intended learners.

Table 6.2 Summary of violations of the design principles

Diagram number

Syntactic analysis Semantic analysis Pragmatic analysis

1 2 3 4 5 6 7 8 9 1  2   3 4  5    6   7    8    9  10  11    12    13     14 (a & b)    15 (a & b)    16   17     18     19     20     21 (a & b)    22 (a & b)       23   24    

The large number of violations observed in the table suggests that the diagrams might fail to achieve their intended purpose of helping learners to understand concepts associated with phases of the Moon. I have shown in the preceding discussion that these problems can best be addressed by using either text, readymade visual aids like charts, modelling activities, or teachers‘ drawings. It is worthy to note that no research has been conducted to investigate accuracy of information presented in text and other visual aids such as charts dealing with phases of the Moon. Also, no research has been conducted to investigate whether, and the extent to which modelling activities prescribed in the books can help learners to understand phases of the Moon. The fact that textbook diagrams have design problems suggests that these other information sources might have problems. Learning would be hindered if these other information sources had problems (further research should be conducted to investigate possible problems in these information sources, so that teachers know the extent to which information presented in these resources can be trusted). If teachers do not fully understand astronomy concepts (as results of this study seem to suggest), then it would be difficult for them to correct information presented in these sources of information.

Teacher training programs should be designed to enhance pre-service teachers‘ understanding of basic astronomy concepts. In addition, these programs should help pre-service teachers to

understand challenges associated with teaching and learning of these concepts. Furthermore, these programs should equip teachers with strategies and techniques that help people to better understand these concepts, e.g. daily moon observations, usage of physical models, and usage of computer software.

As for practicing teachers (some of who have never been trained to teach astronomy concepts), there should be in-service training programmes that focus on (i) enhancing subject matter knowledge of these teachers, (ii) helping the teachers understand challenges associated with teaching the concepts, and (ii) equipping the teachers with strategies that help learners to better understand these concepts. The pre-service and in-service training programs would help teachers to realise strategies and materials that can be used in addition to textbook diagrams (which, as this study shows, have several problems).