Part II
Studies of Conceptual Development
From the questioning of basic assumptions of how we teach traditional geometric concepts to the increased interaction of reasearchers and teachers in creating research-based, teacher-designed activities, researchers with their colleagues, classroom teachers, have begun to rethink what happens in mathematics (in particular, geometry) classrooms.
In this section, we sample that range of work, looking at models of student thinking; studies of interactive, hands-on and computer-enhanced methods of exploring geometric concepts; and the emergence and growth of studentsā reasoning from the primary grades through high school. In chapter 5, Pegg and Davey graft the SOLO taxonomy of modes and levels of thinking (Biggs & Collis, 1991) onto the main trunk of the van Hiele cognitive model. They examine what is perhaps the predominant theory in Kā12 geometry educationāthe model of ālevelsā of teaching and learning proposed by the van Hielesāand take the position that although the van Hiele theory offers a broad framework in which to view cognitive growth in geometry, the theory is not sufficiently fine grained to account for individual differences. The synthesis they propose suggests a way to fine-tune how we look at cognitive reasoning and conceptual development.
Lehrer, Jenkins, and Osana, in chapter 6, report on a 3-year longitudinal study of elementary-grade students that questions (as do Pegg and Davey in chap. 5) the adequacy of the van Hiele model as a description of the progression of childrenās thinking. Their broad-scale portrait of childrenās emergent spatial reasoning skills suggests that current curricular practices in elementary school promote little conceptual development and that, for many children, the opportunities to develop and integrate spatial reasoning skills may substantially diminish before they leave elementary school.
In the next chapter, Lehrer, Jacobson, et al. suggest both that geometry education begins in studentsā informal knowledge and grows in a classroom culture that depends on skilled teachers, teacher-developed models of student cognition, and a comfortable interface between research (and researchers) and teachable moments (and teachers). This particular collaboration between researchers and elementary-grades teachers worked to design activities that stimulated childrenās development of spatial reasoning and their ability to conjecture. The authors trace the growth and development of childrenās conceptions of area and its measure as teachers structure instruction, based on childrenās informal knowledge of space and reallotment, to allow children to experience the conflict between appearance and reality. In closing, Lehrer, Jacobson, et al. note the key roles that invented notations, classroom conversation, and teachersā practices and understanding of childrenās thinking play in the development of conceptual understanding.
Many of the contributors to this section explore ways to use studentsā informal knowledge as scaffolding for more abstract concepts like structure, stability, measurement. Clements, Battista, and Sarama report on a curriculum development project that focused on spatial reasoning, in particular childrenās conceptual development of measurement. They propose that childrenās conceptions of space are based in physical motions like walking, measuring by hand, and so on. They trace the abstraction of length and turn and their measure from situations involving paths (especially the paths made with Logo), noting that this action-based perspective affords ready integration of space and number.
Battista and Clements, in chapter 9, investigate studentsā strategies for spatial structuring and their exploration of volume measure. They find that childrenās reasoning about volume evolves through cognitive restructuring of the shape of space. In this instance, children learn to coordinate and integrate two- and three-dimensional cube representations, working with cube arrays and developing models of cubes as composite spacefilling ālayers.ā
Middleton and Corbett encourage children to explore not only traditional, basic geometric properties like linearity and congruence, but also the more abstract notions of stability (resistance to deformation) and force. Building on childrenās informal notions of structure and stability, they develop engineering contexts that facilitate childrenās understanding and abstraction of relationships between geometry and structure.
Working from the perspective that area and volume measure are essential for the investigation of nature, Raghavan, Sartoris, and Glaser explore the ways that students āmathematizeā their explorations of contexts involving immersible objects that students float and sink. Reporting on the MARS curriculum project, which uses computer modeling to assist integration of mathematical and scientific concepts, they note that students need extensive hands-on activities and call for more attention to the interplay between mathematics and science.
Dennis and Confrey also investigate the interactive roles of tools and representation. They report a case study of the āmethods, voice, and epistemologyā of a high-school student as he investigates analytical geometry with curve-drawing devices that reincarnate forms of thought that have been abandoned for several centuries. The studentās investigations constitute an extended argument for physical exploration of geometric concepts, supported by attempts to representationally and symbolically redescribe what his hands produce with the curve-drawing tools.
One issue explored in several chapters in this volume is the development of argumentation. Koedinger proposes a cognitive model, reflecting that conjecture and argument serve not only discovery, but also problem solving and recall. In his study of secondary-school students, he finds that student arguments are often limited by excessive reliance on overly specific cases, perhaps because student conceptions of form are often rooted in visual prototypes, as noted in the Pegg and Davey and Lehrer et al. investigations. Koedinger also explores the consequences of different forms of teaching assistance and the role of tools for the arguments students develop and strongly suggests, as does Gravemeijer in Part I (chap. 2), that students be guided through their reinvention of concepts.
Collectively, the research reported in this section of the volume takes a wide-angle view of instructional environments and classroom cultures that attempt to promote the development of studentsā understanding. Again we underline the emphasis in these studies on the importance of building (and valuing) studentsā informal knowledge and on encouraging students to physically explore geometry in contexts that support reflection, conflict, and generalization.
REFERENCE
Biggs, J., & Collis, K. (1991). Multimodal learning and the quality of intelligent behavior. In H. Rowe (Ed.), Intelligence, reconceptualization and measurement (pp. 57ā76). Hillsdale, NJ: Lawrence Erlbaum Associates.
5
Interpreting Student Understanding in Geometry: A Synthesis of Two Models
John Pegg
University of New England
Geoff Davey
Christian Heritage College
There is increasing evidence that many students in the middle years of schooling have severe misconceptions concerning a number of important geometric ideas (see, e.g., Burger & Shaughnessy, 1986; Dickson, Brown, & Gibson, 1984). There are many possible reasons for this. A clear divergence of opinion exists in the mathematics community about the methods and outcomes of geometry, and, as a result, textbook writers and makers of syllabuses have failed to agree on a clear set of objectives. Anecdotal evidence suggests many teachers do not consider geometry and spatial relations to be important topics, which gives rise to feelings that geometry lacks firm direction and purpose.
To some extent these problems may be due to the relatively small quantity of research (as compared with, say, research in number) that has been undertaken into studentsā thinking in geometry at the school level, which, in turn, may stem from a perceived absence of a theoretical framework. Even though Piaget and his coworkers published two significant works relating to this area, The Childās Conception of Space (Piaget & Inhelder, 1956) and The Childās Conception of Geometry (Piaget, Inhelder, & Szeminska, 1960) and these have been followed by various studies in the field of spatial cognition, little impact on classroom practice has resulted. Part of the problem lies with Piagetās ātopological primacy theory,ā on which it has proven difficult to build a school syllabus and about which there have been some fundamental doubts (see Darke, 1982).
It was a combination of these problems and their own classroom experiences in the Netherlands in the 1950s that caused husband-and-wife team van Hiele and van Hiele-Geldof to put forward a theoretical perspective for the teaching and learning of geometry. This theory is referred to universally as the van Hiele theory, and the reader is referred to Structure and Insight: A Theory of Mathematics Education (van Heile, 1986) for a detailed account of this work.
In summary, the van Hiele theory is directed at improving teaching by organizing instruction to take into account studentsā thinking, which is described by a hierarchical series of levels. According to the theory, if studentsā levels of thinking are addressed in the teaching process, students have ownership of the encountered material and the development of insight (the ability to act adequately with intention in a new situation) is enhanced. For the van Hieles, the main purpose of instruction was the development of such insight.
Reaction to observed inadequacies in Piagetās formulations also inspired Biggs and Collis to explore ways of describing studentsā understanding more deeply than was offered by current quantitative and qualitative methods. Their work focused attention on studentsā responses rather than on their level of thinking or stage of development. This focus arose, in part, because of the substantial dĆ©calage problem associated with Piagetās work when applied to the school learning context, and the need to describe the consistency observed in the structure of responses from large numbers of students across a variety of learning environments in a number of subject and topic areas. Their research resulted in the development of a categorization system referred to as the Structure of the Observed Learning Outcome (SOLO; Biggs & Collis, 1982). Although the SOLO taxonomy has its roots in Piagetās epistemological tradition, it is based strongly on information-processing theories and the importance of working memory capacity. In addition, studentsā familiarity with content and context plays an influential role in determining the response category.
Although at first glance there may appear to be irreconcilable differences between the two theoretical stances (namely, van Hiele was concerned with underlying thinking skills and SOLO with observable behaviors), a closer examination reveals that the two stances have much in common and that the models are complementary. A synthesis provides a fresh perspective in considering student growth in understanding. The last part of this chapter takes up this theme. First, we give a brief but inclusive review of both models. Second, we consider related research to help develop these ideas further by enabling a comparison of common features. Finally, implications of the findings are explicated and discussed.
THE VAN HIELE THEORY
Since the early 1980s, the van Hiele theory has been under extensive investigation in the western world (for a detailed summary see, e.g., Clements & Battista, 1992; Hoffer, 1981). Although there are two fundamental aspects to the theory, namely, levels of thinking (a hierarchical series of categories that describe growth in student thinking) and five teaching phases (which help guide activities that lead students from one level to the next), the main focus of the research has been on the nature or existence of the levels and the assumptions that underpin them. The initial conception envisaged five levels (see van Hiele, 1986), described here as they relate to two-dimensional figures:
Level 1. Students recognize a figure by its appearance (i.e., its form or shape). Properties of a figure play no explicit role in its identification.
Level 2. Students identify a figure by its properties, which are seen as independent of one another.
Level 3. Students no longer see properties of figures as independent. They recognize that a property precedes or follows from other properties. Students also understand relationships between different figures.
Level 4. Students understand the place of deduction. They use the concept of necessary and sufficient conditions and can develop proofs rather than learn them by rote. They can devise definitions.
Level 5. Students can make comparisons of various deductive systems and explore different geometries based on various systems of postulates.
Although these descriptions are content specific, van Hieleās levels are actually stages of cognitive development: āthe levels are situated not in the subject matter but in the thinking of manā (van Hiele, 1986, p. 41). Progression from one level to the next is not the result of maturation or natural development. It is the nature and quality of the experience in the teaching/learning program that influences a genuine advancement from a lower to a higher level, as opposed to the learning of routin...