NORMES ELECTORALS PER A L’ELECCIÓ DEL PRESIDENT I ELS MEMBRES DE LA JUNTA DIRECTIVA

The first part of this section deals with selection of spatial ability tests from the ETS kit. The second part deals with design of the diagnostic test for the study.

Spatialability tests

I selected six spatial ability tests from the Kit of Factor-Referenced Cognitive Tests developed by Ekstrom et al. (1976) at the Education Testing Service (ETS). Table 3.4 illustrates component of spatial ability measured by each test. I used the Hidden Patterns Test (CF-2) because it measures people‘s ability to mentally detach a figure from distracting background. This skill is needed when interpreting diagrams illustrating phases of the Moon. That is, diagram viewers need to focus at the Moon in one position while ignoring the Moon in other positions which might act as distracting background. In addition to the CF-2 test, I used the Card Rotations (S-1) and Cube Comparisons (S-2) Tests because they measure people‘s ability to mentally rotate objects in space, a skill needed to understand why earth viewers see phases of the Moon (e.g. the turning of the Earth on its axis and Moon‘s orbit around the Earth). The S-1 test is simpler, measuring peoples‘ ability to mentally rotate two-dimensional objects on plane of the paper. Results of this test give information about people‘s ability to undertake mental rotations. The S-2 test, on the other hand, measures people‘s ability to mentally rotate three-dimensional objects in space (similar to understanding phases of the Moon, which requires mental manipulation of three-dimensional objects in space). Thus, the S-2 test is more demanding and more relevant than the S-1 test. Learners who have spatial ability skills needed to mentally rotate objects in space would get high scores on both tests, while learners who

lack these skills would get low scores in both tests. However, learners who are good in mental rotation, but struggle to rotate three-dimensional objects in space would obtain high scores on the S- 1 test and low scores on the S-2 test. Thus, information obtained from the two tests helps us to understand the exact problems that learners encounter when mentally rotating objects in space.

Table 3.4 Spatial ability tests used in the study1

Component of spatial ability

Tests from ETS Kit

Name Code

Spatial Perception Hidden Patterns Test CF-2

Spatial Orientation Card Rotations Test S-1

Cube Comparisons Test S-2

Spatial Visualization

Form Board Test VZ-1

Paper Folding Test VZ-2

Surface Development Test VZ-3

Finally I used the Form Board Test (VZ-1), the Paper Folding Test (S-2) and the Surface Development Test (VZ-3) which all measure people‘s ability to perform a series of mental transformations. The VZ-1 test measures people‘s ability to execute these transformations on the plane of the paper. Results obtained from this test measure people‘s ability to mentally manipulate several objects at the same time. The VZ-2 test is more challenging, measuring people‘s ability to mentally manipulate a paper in three-dimensional space. This test gives more information than the VZ-1 test, i.e. not only about people‘s ability to execute a series of mental transformations, but to execute the transformations in three-dimensional space. The VZ-3 test measures people‘s ability to mentally construct three-dimensional shapes from two-dimensional drawings. Results obtained from this test give information that can help us to understand the extent to which participants can mentally perceive the Earth, the Sun and the Moon as three-dimensional objects from drawings illustrating the Earth-Sun-Moon system.

Learners who have spatial ability skills needed to execute a series of mental manipulations in space would get high scores on the three tests while learners who lack these skills would get low score on these tests. On the other hand, learners who have skills needed to execute a series of mental manipulations in space, but struggle to manipulate 3-D objects in space would get high scores on the VZ-1 test and low scores on the VZ-2 and VZ-3 tests. Furthermore, learners who have skills needed to mentally manipulate 2-and 3-D objects in space but struggle to construct 3-D shapes from 2-D drawings would get high scores on the VZ-1 and VZ-2 tests but obtain low scores on the VZ-3 test. Thus, usage of the three tests helps us to understand the exact problems that learners encounter when endeavouring to undertake a series of mental manipulation in space.

1

I selected tests from the ETS kit for four reasons: (i) the tests were appropriate for learners who participated in the study, i.e. designers indicate that the tests are suitable for persons who have reached Grade 9 and older, but can be administered to younger participants if researchers read out instructions (ii) thorough research was done when the tests were developed, (iii) reliability coefficients show the rests to be very reliable (0.7 and above for S-2 and VZ-2, 0.8 and above for CF-2, S-1 and VZ-1, and above 0.9 for VZ-3), and (iv) comparison can be made with other studies because the tests are widely used. When discussing the results, I pay attention to similarities and differences between skills measured by the tests, and skills needed to understand phases of the Moon.

The diagnostic test

Diagnostic tests are usually pencil-and-paper techniques used to identify existing knowledge and competencies, and to identify areas of strength and weakness (Fraser, 1991). Diagnostic tests have the following advantages (similar to advantages of questionnaires discussed by Cohen & Manion, 1995; Fraenkel & Wallen; 1990; McMillan & Schumacher, 1993; Oppenheim, 1966 and Sax, 1968) which are applicable to the study: (a) they are a relatively cheap way to gather research data because they do not necessarily require a researcher to travel to individual respondents, (b) they do not need to be administered by trained staff, (c) data can be obtained from large samples in a short time, (d) processing and analyzing the data can be simpler and quicker than is the case for interviews.

Design of the diagnostic test: The first step in the design of the test was to specify content knowledge to be evaluated through the test. It should be remembered that the curriculum requires (i) Foundation Phase learners to know that spatial objects such as the Sun, the stars, the Moon and the planets can be studied to establish pattern of their movements and their relative positions, (ii) Intermediate Phase learners to know that the apparent shape of the moon changes in a predictable pattern, and to further know that the motion of the Moon relative to the Earth and the Sun can be used to explain these changes, and (iii) Senior Phase learners to know that most spatial objects are in regular and predictable motion, and to further know that the motions of the Earth and the Moon explain phenomena such as phases of the Moon.

Section 4.3 (84-88) gives details about the content knowledge evaluated by the diagnostic test. The knowledge statements discuss issues associated with (i) the regular and predictable motion of the Earth such as the Earth's rotation and its orbit around the Sun, (ii) the regular and predictable motion of the Moon such as duration of Moon's orbit around the Earth, the rising and setting times of the Moon during each phase, the reasons why the Moon rises later each day, and time lapse between phases of the Moon, and (iii) regular and predictable appearance of the Moon, the shape of the Moon seen from earth during each phase, and reasons why the Moon appears to face opposite directions as seen from different hemispheres.

I used the knowledge statements to design the diagnostic test (see the test in Appendix B). The test consisted of 11 questions.

 Questions 1 – 7: These were multiple-choice questions testing learners‘ background knowledge on concepts associated with phases of the Moon. All these questions could be answered using knowledge taught in schools (from Intermediate Phase to Senior Phase as required by the curriculum). In addition, learners with good understanding of the Earth-Moon-Sun system, and those who have stayed in environments that enable view of the sky at night (e.g. where there is no electricity) could get correct answers for most of these questions.

 Question 1 investigated learners‘ understanding of the duration of a complete cycle of moon phases (related to regular and predictable motion of the Moon). This question investigated factual knowledge that learners have to be told.

 Question 2 investigated learners‘ understanding of the rising and setting times of the Moon (related to regular and predictable motion of the Moon). This question can be answered using factual knowledge that learners have to be told. In addition, learners who understand the Earth-Moon-Sun system could get a correct response for this question.

 Question 3 investigated learners‘ understanding of time lapse between phases of the Moon (related to regular and predictable motion of the Moon, and predictable pattern of the Moon’s phases). Like the previous question, learners who have a good understanding of the Earth-Moon-Sun system could get a correct answer for this question. In addition, learners who regularly see the Moon in the sky could get a correct answer for this question.

 Question 4 investigated learners‘ understanding of the delay in rising times of the Moon from day to day (related to regular and predictable motion of the Moon). Learners who have everyday experience with the Moon (e.g. who regularly see the Moon) could get a correct answer for this question, even if the topic had not been taught in schools.

 Question 5 investigated learners‘ understanding of the cause of moon‘s phases (related to the fact that the motion of the Moon relative to the Earth and the Sun can be used to explain changes in apparent shape of the Moon).

 Question 6 investigated learners‘ ability to link phases of the Moon, position of the Moon in the sky, and time of day (related to relative positions of the Earth, the Sun and the Moon, and phases of the Moon). Learners who have a good understanding of the Earth-Moon-Sun system, and/or those who regularly see the Moon in the sky could get a correct answer for this question.

 Question 7 investigated learner‘s understanding of the fact that all viewers on earth see the same phase of the Moon in a particular day, irrespective of locations of viewers on earth (related to regular motion of the Earth, and phases of the Moon).

 Questions 8 – 11: These questions tested learners‘ ability to mentally manipulate spatial information presented in diagrams.

 Question 8 illustrated a viewer (P) on earth and an astronaut (A) on the Moon. The Moon appeared to be crescent-shaped as seen from the Earth (see Figure 3.2).

Figure 3.2 A diagram from Question 8

The question asked learners to determine the phase of the Earth that would be seen by the astronaut. To answer the question, learners needed to determine a configuration of the components of the Earth-Moon-Sun system for which earth viewers would see the crescent moon illustrated in the diagram, and to imagine looking at the Earth from the Moon in this position (related to relative positions of the Earth, the Sun and the Moon, and phases of the Moon).

 Question 9 tested skills necessary to determine phases of the Moon from diagrams, using a diagram that was likely to be familiar to the learners. The question illustrated the Earth, the Moon in eight positions around the Earth, and the Sun‘s rays shining on the Earth and the Moon (see Figure 3.3)

Figure 3.3 A diagram from Question 9

The question asked learners to determine phases of the Moon in positions 1, 4, 5, 7 and 8 as seen from the earth shape. Learners who had used this diagram before would be in better position to answer the question, than learners who had never used the diagram. In addition,

Earth

P A

learners with high spatial ability skills could outperform learners with low spatial ability because the question required respondents to manipulate objects in space.

 Question 10 illustrated the Planet Mars, its two moons, and the Sun‘s rays approaching the planet and its moons (see Figure 3.4).

Figure 3.4 A diagram from Question 10

The question asked learners to determine the phase of Phobos as seen from Deimos. This questions required learners to use diagrams to determine the shape of one spatial object as seen from another, a skill needed to interpret diagrams illustrating phases of the Moon. Failure to get the correct answer to this question suggested that learners would likely struggle to interpret diagrams illustrating phases of the Moon.

 Question 11 tested learners‘ ability to perform simultaneous rotation and revolution of spherical objects. The question illustrated the Planet Mercury in its orbital path around the Sun. A crater (C) was illustrated on the surface of Mercury (see Figure 3.5).

Sun

Mercury C

Figure 3.5 A diagram from Question 11

The question asked learners to draw the planet and its crater after a given duration of time (in days), thus investigating learners‘ ability to perform simultaneous rotations and revolutions needed to understand phases of the Moon. Failure to get a correct answer indicated that learners would likely struggle to understand concepts requiring simultaneous rotation and revolution of spherical objects.

Format of the test: The test consisted of five pages, a cover page and the questions in four pages (see Appendix B). The cover page had the following sections: (a) a space for learners to write their

Deimos Mars Phobos Sun’s rays

names, (b) a question asking learners to indicate whether they had been taught about phases of the Moon, and the grade level in which they learned about the topic, (c) information explaining importance of the study, (d) the instructions explaining how to answer the questions. The four-page test was printed on both sided of an A3 sheet, which was then folded to make a booklet.

Each question had a confidence scale asking learners to indicate how certain they were about correctness of their responses. In addition, Questions 8-11 each had a visualization scale asking learners to indicate how easy it was for them to visualize what the diagrams illustrated. The diagnostic test consisted of spaces for learners to indicate specific problems encountered while responding to the test.

Validation of the test: The test was content-validated by two experts: an astronomer doing some work with school learners on astronomy education, and an experienced science education researcher who had interest in astronomy education. I asked the experts to check (a) clarity of instructions, (b) scientific accuracy of content in the test, (c) appropriateness of terminology used in the test (d) appropriateness of multiple-choice distractors, (e) whether the test fairly covered intended content, and (f) any other issues they could find interesting. Responses from these experts resulted in modification of instructions, simplification of language, and modification of some items. For instance, the astronomer suggested modification of the diagram in Question 10. In this diagram, the two moons were almost equidistant from the planet. The astronomer indicated that if this were the case, the moons would collide as they orbit the planet.