A Critical Review of Curriculum Mapping: Implications for the Development of an Ethical Teacher Professionality

Curriculum mapping, a curriculum design methodology popularised in America has found favour in New Zealand schools as they develop their own curricula in line with the recently introduced New Zealand Curriculum. This paper considers the implications of curriculum mapping for the development of an ethical teaching profession. Curriculum mapping is problematised because it reflects positivist theories of knowledge and leads to further technicisation of schooling. The requirement that schools develop their own curricula could however open the possibility to develop pedagogically and theoretically sound curricula and offers teachers and managers the opportunity to regain ownership of their work as they review their current curricula, leading to engagement in a genuinely ethical and collaborative dialogue


INTRODUCTION
This paper investigates the impact that the implementation of the 2007 New Zealand Curriculum could have on the development of an ethical teacher professionality. In contrast with the notion of 'teaching as a profession', which suggests some passivity on the part of the members of a profession who are ascribed by that profession, that of 'professionality' allows the possibility that a teacher self-consciously makes and creates an identity through praxis. This is a dialectical process whereby action is informed by theory, and theory is shaped by refection on action. Such a process may allow a teacher to take up a transformative role in a liberating education in which teaching is based on dialogue; personal experience is considered as a text and starting-point for the acquisition and development of knowledge; and teacher, student and school are motivated by a vision of a just and critical democracy beyond the classroom.
For Paulo Freire (1970), it is the 'ontological vocation' of people to become more fully human. This 'ontological vocation' is the point of peoples' existence, which "...is to be a Subject who acts upon and transforms [his/her] world, and in so doing moves toward ever new possibilities of fuller and richer life individually and collectively" (1970, p. 14). Reflecting that theoretical insight, this paper will propose that the ontological vocation of teachers is to become 'ethical professionals'. The idea of 'vocation' implies commitment and a sense on the part of the teacher that there is a purpose beyond the present for both teacher and student. This concept captures too the idea that teachers are in a state of becoming and moving toward the attainment of their own potential as professionals, as persons motivated by an altruism that is based on a sense of 'the other', duty and service.
Orientation to 'the other' requires acting out of concern for other people rather than out of concern for one's own interests or, for example, those of the Ministry of Education. Duty can be conceptualised as accountability, which is extrinsic in effect (such as being in class when required to by the timetable, because that is what one is paid to do) or as responsibility, which is intrinsic in effect (such as recognising the needs of a student who wants extra help to get better results and therefore making time available after school to help that student). 'Service' suggests one is working for others and in their interests, placing these above or beyond one's own, and that this work is carried out for reasons other than extrinsic, material ones (Wise, 2005). This idea of 'service' is sometimes conceptualised as 'social responsibility' (Brien, 1998). It is a necessary component of the altruism that characterises ethical professionality for a teacher to be motivated by a belief in the good of people and the ability to enhance that goodness, to 'make a difference'. These characteristics are not, however, necessary to teaching. It is quite conceivable that there are people in teaching who have a low opinion of their students and of the world in general and who do not believe that their effort will make one iota of difference to the lives of anyone. Such people however, could not on the account given here, be considered as 'ethical' professionals.
The use of the term 'ethical' in a schooling context refers to teaching as a multi-faceted value-laden and normative activity that focuses on people, making their motivations, desires, beliefs and goals central to teaching. It calls on all those concerned to have positive regard for others similarly engaged, either as students or teachers. Teaching occurs in a broader context of socio-political and economic policy, and those wishing to develop their sense of professionality are required to identify these greater demands made by their profession in regard to each other and their students. They are called to be critically aware of the broader context in which their work occurs, an awareness that challenges the dichotomy created by 'neoliberal technoscientific education'; between a broader liberating education and the narrow economic intentions of vocationalism (Freire, 1996a, p. 131). As Freire noted elsewhere, transformative education requires teachers and students 'to understand the social context of teaching' (Shor & Freire, 1987, p. 33). Bell and Stevenson (2006) also drew attention to the socio-political context of policy making and noted that the important questions to ask are: what is the dominant discourse? What or whose interests are served?
This paper is concerned with the process of 'curriculum mapping', one that may seem initially to be a non theoretical matter. Despite the likelihood too that teachers' approach to curriculum mapping will probably be non theoretical, this paper seeks to unpick relevant theoretical issues that will clarify curriculum mapping and subject this process to critical review. Such a review is necessary in light of the emergence of curriculum mapping in education discourse in New Zealand around the introduction of the 2007 New Zealand Curriculum, and the significance that curriculum mapping may come to assume in the minds of many school leaders who could feel compelled to implement a process to which they have not given critical thought. The relevance of this paper also lies in its contribution to a study of the ethical-professional role of teachers in modern schooling in New Zealand, particularly because one of the claims of curriculum mapping is that it contributes to the development of teacher professionalism (Tuchman Glass, 2007).
A Freireian approach to educational understanding highlights the political nature of education and schooling. There is no neutral education and there is no neutral curriculum. The notion of 'curriculum mapping' is nevertheless conveyed in the literature as a 'neutral', depoliticised process. It must be noted, however, that "…those who hold power define what education will be, its methods, programmes and curriculum" (Connolly, 1980, p. 70). Curriculum mapping, it will be suggested, has to be contextualised, along with any policy that drives such practical implementation measures, within a broader understanding of power and its application.
The term curriculum mapping now requires explanation including a consideration of some of the metaphors by which it is often explained in the literature. This use of metaphors serves a dual purpose; it gives a rather mundane planning process a mystical or abstract status whilst simultaneously placing this seemingly complex process in the hands of classroom teachers. The process of curriculum mapping will be canvassed briefly before considering the claims made on its behalf in the curriculum mapping literature. Because the process of curriculum mapping suggests that teachers 'stand back' from their practice, and because the New Zealand Curriculum gives significant status to self-reflection and metacognition, some comments will be made to evaluate the relationship between curriculum mapping and critical teacher reflection. Notwithstanding this critique, balanced consideration will be given to the possibility that the process of curriculum mapping may have some role to play in developing an ethical teacher professionality.

WHAT IS CURRICULUM MAPPING?
Curriculum mapping "…is an invaluable tool that can help schools clean their closets" (Erickson, 2004, p. vi). It is an analysis and assessment of a school's current curriculum offerings in relation to prescribed competencies or standards of performance. The resources and assessment used to support the teaching of both content and competencies is also recorded. A curriculum map attempts to assess what a school currently offers against an ideal or desired set of competencies or attributes. It does so by exposing gaps or overlaps in course offerings. It is a process that has been employed also at the tertiary level (Sumsion & Goodfellow, 2004). Not all the literature accords with the description of the preceding paragraph, however. Some authors prefer to see a curriculum map as a diary that captures in real time what is actually taking place in the classroom against what is planned, recording this as a description of content and competencies taught or standards being aimed at (H. Jacobs, 2004).
A curriculum map is presented as a table reflecting competencies or standards along one axis and the unit topics or curriculum content of specific areas (e.g. social studies) along the other axis. Where intersections occur, the degree of the fit between the two points is noted either simply by ticking or by written description. This type of map aids the analysis of a school's present situation. A journal or diary map will have timeframes along one axis (e.g. months) and competencies, content, standards, resources and assessments along the other axis, with the intersecting blocks being entered and completed with the relevant information.
Experienced practitioners will realise that what is described represents nothing other than a curriculum overview, or a scheme of work. The key element that may set curriculum mapping apart from what are really standard tools of practice is the intention that it be implemented school-wide and even clusterwide (a group of similar schools in a defined geographical area).
The elevation of otherwise routine and taken-for-granted practices to the status of academic theory presented in expensive text books suggests that there may be some justification to reflect on the process of self-promotion by 'experts'. Dressing established practice in bright new garb, and promoting it as 'the next big thing', suggests that some duplicity or mystification is afoot. Nowhere is this more evident than in the use of metaphor. The literature reviewed for the purposes of this paper uses several: mapping, of course, is the central one. However, presumably to make 'mapping' a more accessible concept, metaphors of building, cookery and pastry-making are also deployed. These metaphors require some teasing out to provide some insight into the process of mysterymaking.
Cartographers use available empirical evidence, such as satellite imagery, and in earlier times, on-the-spot visual experience to note in symbolic form what is there 'in the world'. In this sense, cartographers practice a very pure empiricism, relying on sensory experience to detail a world apart from the cartographer. Needless to say, this empirical evidence is still filtered through the experience of the cartographer and the cartographer may make decisions about what to include and what to exclude that actually have a bearing on the final product. The map is at best a symbolic representation of reality -it is not reality itself.
As a mode of explanation, a mapping metaphor is imperfect because it purports to be an objectification of a reality that is complex and not value-free. It implies that there is a pre-assumed route that is best, and that the time and distance of the journey can be predictable. Finally, a mapping metaphor attempts to depoliticise and deproblematise a reality that may be serving to oppress the marginalised or to mystify the relations of power at work in the broader curriculum or in the school itself.
There are super-metaphors or meta-metaphors present in the literature that are seemingly required to clarify the mapping metaphor: "I see the … curriculum map… as the overall balance of a well-rounded menu…" (Tuchman Glass, 2007, p. xvii). Like the mapping metaphor, a menu-planning metaphor also serves to disguise reality and fails to acknowledge that not all schools have kitchens or larders of equal size; not all schools have chefs of equal ability and nor do all schools get to serve customers of equal discernment and refinement. Indeed, one of the driving forces behind the New Zealand Curriculum of 2007 is an acknowledgement of at least the final of these three caveats, although its creators have failed to take heed of the essentially discriminatory and uneven state of affairs in New Zealand schooling as regards the first two caveats, namely resourcing and teacher quality.
A third super-metaphor is a building metaphor: "… curriculum mapping is like a tool belt because it contains or holds information about what a teacher really teaches…" (Truesdale, Thompson, & Lucas, 2004, p. 11). In reference to reluctant teachers (rocks): "… the rock has to be extracted. Removing rock (extracting old attitudes) and bringing in new dirt (introducing new information about teaching and learning) were necessary before lay[ing] the foundation for curriculum mapping" (2004, p. 19). This unfortunate super-metaphor also implies predictability, certainty and single outcomes that may not be desirable in real learning (Rolling, 2006). Neither the mapping metaphor nor the two supermetaphors outlined here are especially helpful in better understanding the significance, pitfalls or benefits of curriculum mapping or the contribution it could make to developing ethical teacher professionality or to transforming education.

THE PROCESS OF CURRICULUM MAPPING
The 'how to' literature provides clear guidelines about the mapping process, despite the contrary views of some critics (Sumsion & Goodfellow, 2004). However, if these writers consider that there is "surprisingly little guidance concerning the process" (2004, p. 333) this may be because they expected more of curriculum mapping than it actually entails. The key step in the process is attaining consensus from all teaching staff on the value of the process and staff ownership of the process and what it entails, because the process is on going. Sumsion and Goodfellow (2004) noted that in a 'stock-take' type mapping exercise staff may feel threatened and under surveillance (pp. 336-337), whilst the on-going commitment to maintaining the mapping process may require shifting resistant staff attitudes (Truesdale, Thompson, & Lucas, 2004, p. 11).
As earlier indicated, however, the key purpose of mapping is to ensure that delivered curriculum content is addressing defined skills or competencies and providing opportunities for students to be assessed against standards, learning outcomes, or achievement objectives. The process for establishing this may vary from school to school, but will entail individual teachers or teams of teachers completing the required spaces within intersecting grid blocks. Once overlaps or gaps are identified, these have to be addressed so that leading into the next academic year, the school can adopt a more coherent and systematic approach to its teaching of the curriculum. Following the curriculum mapping process will require that whole-school overviews outlining what is planned for the year ahead are prepared. These will have to be monitored and reported against throughout the year, at the end of specific teaching units, for example, or other chronological benchmarks such as each month.
Curriculum mapping emphasizes the requisite that teachers and administrators focus on the balance between what really took place in individual classrooms and what was planned individually or collaboratively. This data is measured in real time: recorded by months or grading periods (Hale, 2004(Hale, -2008.
This brief description gives rise to a number of issues: the role of competencies; the role of standards; questions of technical-rationalist orientations to student learning and teachers' work; questions of whole-school collaboration over individual autonomy; the primacy of planning and recording over teaching; and the enormous commitment of time, effort, and personresources such a process will entail.

THE CLAIMS MADE BY CURRICULUM MAPPING
"Essentially, the CYO (Curriculum Year Overview) provides teachers with a curriculum road map for the year" (Tuchman Glass, 2007, p. 3). This claim is expanded by reference to milestones on the journey that provide direction to teachers in a well-organised curriculum, and presupposes that teachers in a school are working from a unitary well-defined plan that takes account of all contingencies and that they have achieved consensus over the plan. The claim is supportable and defensible so long as such a plan and level of consensus can be attained. The difficulties lie not so much in whether the claim is workable or feasible but in whether all the teachers in a school can be unified voluntarily in the pursuit of joint or common planning, and whether the time can be created to allow this planning to occur. This concept of joint or common planning suggests too that the classical concept of a teaching professional working as independently autonomous cannot be sustained in a context where mutual collaboration and support is required. Should the barriers of time and mutual collaboration be overcome, the philosophical purposes and understandings of learning come into question to challenge the workability of such a plan. Tension runs along a fault line between learning as a serendipitous activity or as one that can be planned predictably with set outcomes. As Rolling (2006, p. 41) has suggested, "… learning is no sure thing and it is not easy to map…" Clearly then, this claim rests for its success on all teachers in a school collaborating mutually on a plan and a process for which there is consensus, underpinned by a philosophical acceptance of learning as a predictable activity leading to predictable outcomes.
Matching curriculum content and desired skills or competencies and assessment to standards (statements of desired achievement outcome) is at the essence of the process of curriculum mapping (H. H. Jacobs, 2004b, p. 5;Truesdale, Thompson, & Lucas, 2004, p. 13;Tuchman Glass, 2007, p. 3); with the latter theorist claiming that teaching to standards 'validates what teachers do' and that curriculum mapping validates teaching to standards. What this claim suggests is that as long as a teacher's activity is geared towards the standards of achievement then that activity is valid. Furthermore, curriculum mapping will help teachers align their content and assessment with the required standards and so keep them 'on track', ensuring that they do only 'valid' work. The implication of Tuchman Glass's claim is that any teaching not linked to standards of achievement does not count as 'teaching'. Indeed, she goes on to say that a teacher "…cannot manage or teach effectively what one does not measure" (2007, p. 3). There is little likelihood suggested here of any personal development of a teacher seeking transformation as an ethical professional or seeking to be an agent for educational transformation if all that teaching amounts to is instruction against standards that pre-determine the outcome of teaching.
The New Zealand Curriculum "…encourages all students to reflect on their own learning processes and to learn how to learn" (Ministry of Education, 2007, p. 9). 'Learning to learn' implies a critical and constructivist mode of pedagogy, yet curriculum mapping simply reinforces learning what to learn through the rigid adherence to pre-set standards and learning outcomes that predict where the learning process will lead. Adherence to prescribed Learning Outcomes is in conflict with learning to learn and lifelong learning:

Social-constructivist teaching and learning is … open to variation in
the outcome of what has been learned, and more reliant on teacher authority than on state authority. It also requires … [teachers who are]… mature, experienced, confident, resourceful, and lifelong learners. (Grace, 1997, p. 50) Moreover, in an already crowded curriculum, pressures on the time the teacher has available are significant, the stakes are high, and the standards dictate what the process should be. Constructivist learning in contrast requires patience and time to allow students to co-facilitate and make meaning as they go. This suggests that constructivist practices -like inquiry learning -may be implemented only in short bursts, thus not allowing 'learning to learn' to become fully embedded. The political question of who has the power to decide the standards is germane, because it clearly is not teachers and definitely not students. The standards are outlined as 'achievement objectives' in the form of unpaginated fold-outs at the rear of the New Zealand Curriculum (2007), and are provided in far greater detail within the pre-existing Curriculum Statements by Learning Area that are used now to supplement the new document. At Years 11 -13 (Level 1 -3 on the New Zealand Qualifications Framework [NQF]) standards are detailed on the NQF, each one describing what a "learner needs to know or what they must be able to achieve" in order to meet the standard (Davies & Burke, 2004, p. 8). These pre-determined standards represent a particular set of socio-cultural norms (i.e. middle-class, mainly Pakeha New Zealand) which are being imposed on increasingly culturally diverse students. Yet their teachers have to operate in a national curriculum framework predicated on conceptions of student metacognition and co-constructivist learning that presuppose an environment in which a more radical pedagogy can flourish and in which the outcome of learning cannot be easily predicted. There is an inherent contradiction in the New Zealand Curriculum between teaching to standards and teaching students to become independent lifelong learners in classrooms where knowledge is co-constructed and where both teacher and student engage in the development of metacognitive abilities. Jacobs (2004b, p. 2) claimed that curriculum mapping brings about measurable improvement in student performance, but she fails to provide documentary or statistical evidence. A review of related curriculum mapping literature (H. H. Jacobs, 2004a;Johnson & Johnson, 2004;O'Neil, 2004;Truesdale, Thompson, & Lucas, 2004;Tuchman Glass, 2007); reflects the same lack of evidence of improved student performance. Indeed, O'Neil (2004, p. 52) listed the advantages of curriculum mapping as reported to him by teacher survey, without a single reference to enhanced outcomes for students. In conclusion, he considered that students "are the most important impact group" (2004, p. 62) who will "ultimately reap the benefits". While Johnson and Johnson (2004, p. 50) reported that curriculum mapping was the "hub that focused the work of the district on enhancing student achievement", they too failed to report any research findings or data to support this claim. They resorted instead to the conclusion that curriculum mapping has allowed teachers to "become dreamers and confident risk-takers in their quest to help all students become independent and lifelong learners" (2004, p. 51).
Of the first two claims, namely that curriculum mapping "provides teachers with a curriculum road map for the year" (Tuchman Glass, 2007, p. 3) and that it can match curriculum content and desired skills or competencies and assessment to standards, curriculum mapping can do what it claims. This is so on the proviso that alignment of the teachers in a school with the concept and practice of mapping can be attained, and assuming acceptance that teaching is an activity geared to the extrinsic pursuit of student attainment of specified standards. On the third claim, that curriculum mapping brings about measurable improvement in student performance based on the available literature to hand, there seems to be no evidence. It can be assumed that a curriculum programme that is streamlined, efficient, without overlaps and that attends to the acquisition of competencies may lead to better outcomes for students. However, to make the claim without any primary research evidence suggests that the claim should not be made until such evidence is forthcoming. The balance of the claims made for curriculum mapping may be more promising, because these are the claims related to the reduction in isolation between teachers and schools, and the enhancement of collaboration amongst teachers and schools. Both lead to a result in which the professionality of teachers may be enhanced.
The writers cited above make common claims that relate to enhanced professionalism for teachers. The claims suggest that curriculum mapping fosters teamwork and "elevates teachers' level of professionalism" (Tuchman Glass, 2007, p. 10); can "provide a process for collegial dialogue" (Truesdale, Thompson, & Lucas, 2004, p. 24); and requires cross-departmental dialogue that leads to a "rewarding professional openness" (H. H. Jacobs, 2004a, p. 28) and "more collaboration within and across departments" (O'Neil, 2004, p. 53). There is however no reference in the curriculum mapping literature reviewed here to teachers being critically self-reflective, seeking to problematise their reality and to give shape to policy in their own words and on their own terms. On the evidence above curriculum mapping assumes that teachers must accept the status quo of externally applied standards that predict and shape the process and outcome of teaching and learning. What curriculum mapping does is ensure that a school and its teaching staff are teaching to these standards in a systematic, organised wayone that eliminates unnecessary overlaps or gaps so that student chances of achievement are maximised.
Acceptance of the status quo in this way by teachers is a collective decision and it depends in part on a collective fear of freedom and on an identification with the 'oppressor consciousness' (Freire, 1996b). It has already been noted that some of the claims made in support of curriculum mapping require a high level of consensus around not only the concept and process of curriculum mapping but also around a conception of teaching that focuses on the reproduction of a dominant cultural norm that reduces all learning to the attainment of standards and student regurgitation of a 'hegemonic canon' (Spaedman, 1999). By identifying with the 'oppressor consciousness', teachers, perhaps unwittingly, become oppressors themselves. The 'elevation of teachers' professionalism' suggested by curriculum mapping is precisely the form of 'reprofessionalisation' that is promoted from within the Ministry of Education; one that does not see teachers become liberated to seek the attainment of their ontological vocation, and in so doing seek to transform the lives of their students so that they in turn may become autonomous, responsible political actors (Spaedman, 1999). Rather this 'reprofessionalisation' replaces what has been rubbed out systematically by two decades of neo liberal, market-oriented reform that has turned teachers into assessment managers and functionaries.
Having lost so much, teachers now eagerly take up what the oppressor offers, and in this sense identify with the oppressor. However, to seek authentically to realise their ontological vocation as ethical professionals calls on teachers to become critically aware of this oppressor-oppressed relationship, and to act decisively to liberate themselves by, at the very least, becoming critically self-aware agents who render the oppressor consciousness redundant. Freire (1996b) likened this to the Hegelian dialectic -to exist or to have a reason to continue existing, the oppressor needs the oppressed to continue lapping up the sops handed to them by the oppressor. To turn this situation on its head, so to speak, requires perhaps that teachers become 'self empowering critical activists'.
The New Zealand Curriculum calls on teachers to educate their students to be self reflective, which implies that teachers too are required to be self reflective. This process of introspection may be aimed at the teacher coming to a greater self-knowledge and translating that knowledge into changing and enhancing practice. This painful process of critical self examination requires the agent to be brutally honest, to be questioning, and to consider the possibly negative effects that the agent's previously unquestioned assumptions may have had when turned into action in the world of practice. Being critical calls on the agent to be willing and able to court controversy, to accept the limits of personal knowledge, to be able nevertheless to seek knowledge by cross-disciplinary analysis that removes some of the traditional barriers to knowledge enquiry, and to accept the notion of and participation in a collaborative project of meaning making; namely that meanings are constructed in the context of cultural communities of people (Greenman & Dieckmann, 2004, p. 242). Given these attributes, critical self reflection is aimed at more than mere introspection. The goal of this process is to lead the teacher to transformative pedagogical practices that will enable students to themselves become critical self reflectors, with the ultimate aim of sharing in collaborative cultural meaning making. Because curriculum mapping claims to be affirming the professional status of teachers then this must mean that curriculum mapping will allow teachers to be more critically self reflective in order that they are able to realise their ontological vocation. Nothing in the research however indicates that curriculum mappers have any notion of transformative pedagogy as suggested here.
A critical pedagogy calls on teachers to engage students in meaningful learning experiences in which both teacher and student co-operate as travellers on the same road. The teacher is still learning despite many years more experience. This position makes teachers vulnerable, and calls into question what some students may consider appropriate behaviour for a teacher. These critical approaches to classroom practice are acquired dispositions and cannot be reduced to a bullet point item in a relevant box on a curriculum map. The claims thus made by curriculum mappers to positively influence teacher professionality are at best shallow and trite. They beg more fundamental questions regarding what really constitutes critical teacher professionality.

CONCLUSION
To be authentic curriculum mapping must allow teachers to perceive their reality critically and to be made aware of what supports that reality, such as understanding the power relations that allow the exercise of hegemonic cultural values and practices over all aspects of society and the extent to which teachers 'buy in' to that reality. Teachers must commit to bringing about some fundamental transformation in their own professional lives which includes aiding their students to become autonomous beings, for this authenticity to be realised. Furthermore, teachers have to understand that not only should their critical reflective activity lead to changes in their practices but that these new practices also require further reflection and transformation. This dialectical process is the praxis that is fundamental to Freire's thought (1996b). Clearly, the literature on curriculum mapping cited in this paper bears no resemblance to this process. However, the process of curriculum mapping does stumble over a potential gem: that which lies in the possibilities for dialogue, cross-departmental and intraschool collaboration and critical conversations about what it is worthwhile to teach and learn. The extent to which these possibilities bear fruit in the transformation from 'banking education' (Freire, 1996b) to a radical pedagogy that "provides the conditions for students to become autonomous" (Spaedman, 1999, p. 26) will depend very heavily on the critical consciousness of the curriculum leaders in a school and the teachers themselves. It will depend on gaining consensus about transformation rather than a mechanistic process of teaching to standards.

University of Auckland
Leon Benade is a Doctoral student in the School of Critical Studies in Education at the University of Auckland. His thesis explores the question of the spaces created by the 2007 New Zealand Curriculum for the development of an ethical teaching profession.
He is also an independent education consultant and Director of Mockingbird Education Management Consultants (www.mockingbird.co.nz ). In this capacity he works with several schools as they implement the 2007 New Zealand Curriculum. This paper is a modified version of one that was presented to a Doctoral Symposium held at the University of Auckland on 5th Apr 2008.
Contact: leon.w.benade@aut.ac.nz The opinions expressed are those of the paper author(s) and not the New Zealand Journal of Teachers' Work. Copyright is held by individual authors but offprints in the published format only may be distributed freely by individuals provided that the source is fully acknowledged. [ISSN-1176-6662]