What should we teach about science? A Delphi study - Evidence-based Practice in Science Education (EPSE) Research Network

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Evidence-based Practice
in Science Education (EPSE)
Research Network

What should we teach
about science? A Delphi

Jonathan Osborne, Mary Ratcliffe, Sue Collins,
Robin Millar and Rick Duschl

   Executive Summary                 1

   Introduction                      4

   Teaching the Nature of Science:   7
   Difficulties and Dilemmas

   Methodologies and Findings        19

   Conclusions and Implications      75
Executive Summary

In the past century, school science has been dominated by the educational
requirements of our future scientists. That is, it has become and remained
fundamentally an education in science for those who wish to pursue scientific and
technically related careers. However, during the past two decades, the growing
concern about the relationship between science and society has led to a concern to
improve the quality of formal education about science – in short, to ask what kind of
school science education is required for citizenship in a participatory democracy? For
the separation of scientific knowledge from the political, cultural and historical
context of its production endows it with status as exact, ‘true’ and absolute – leaving
the public without the skills to understand science in a variety of public contexts
where scientific knowledge is often contingent and tentative. And, given that
scientific and technological issues are increasingly dominating the political agendas
confronting society, the meagre public education about science undermines societies’
commitment to democratic pluralism. For the lack of any understanding of how
scientific knowledge is produced, how it is evaluated or the motives for its production
leaves its citizens too dependent on the knowledge of experts for critical decision

Yet, part of the difficulty of determining what should be taught about science is the
failure to agree an acceptable account of science within the scientific community, or
amongst philosophers and sociologists, let alone between the various communities.
Hence, the lack of any consensus makes the task of defining that aspect of the formal
science curriculum which might portray ‘ideas about science’ problematic for policy
makers – the more so as there is, in contrast, a well-established consensus about the
content aspect of science curricula.

This study sought, therefore, to make a contribution towards clarifying this debate and
dilemma by seeking to establish empirically the extent of consensus within the
relevant communities about a simplified or ‘vulgarised’ account of science. That is it
sought to determine the characteristics of scientific enquiry and those aspects of the
nature of scientific knowledge that should form an essential component of the school
science curriculum.

The study reported here sought to explore this issue by undertaking a Delphi study
with a group consisting of 23 individuals drawn from 5 groups – scientists,
philosophers, sociologists of science, science educators, and science teachers.
Members of the first four groups were recruited on the basis that they held an
international reputation in the field, or were Fellows of the Royal Society. Science
teachers were selected on the basis that they had either received awards for the quality
of their teaching, or had published notable textbooks in the field. As is standard in all
such Delphi studies, none of the participants were aware of who the other participants

Executive Summary

The study consisted of three rounds. In the first, the participants were asked to
answer three open-ended questions about science education up to the age of 16.
These were:

     1.        What, if anything, do you think should be taught about the methods of
     2.        What, if anything, do you think should be taught about the nature of
               scientific knowledge?
     3.        What, if anything, do you think should be taught about the institutions and
               social practices of science?

The data from this first round was systematically coded and 30 broad themes emerged
in three major categories: - The Methods of Science, The Nature of Scientific
Knowledge, and The Institutions and Social Practices of Science. In the second
round, a summary descriptor was generated for each theme and returned to the
participants together with a selection of supporting comments. Participants were
asked to rank the importance of the theme and justify their ranking with written
comments. This process led to a reduction in the number of themes to 18 which were
again returned to participants for ranking and comment in the third and final round.
From this final round emerged 9 themes which were ranked 4 or above (on a 5 point
scale) by at least two thirds of the participants, and whose average rating changed by
less than 33% between round 2 and round 3.

Conclusions and Findings
Two major findings emerge from this study:

1. There exists support and broad agreement for nine themes dealing with aspects of
   the nature of science that school students should encounter by the end of
   compulsory schooling.

The evidence supporting this conclusion is the high degree of consensus concerning
these themes and the high stability in the positive ratings of their importance, both
within and between groups.

2.        Many of the aspects of the nature of science represented by the themes have
          features that are interrelated and cannot be taught independently of each other.

This second conclusion emerges from the copious comments made by many of the
participants about the emerging themes. These participants recognised both that the
account of science represented by the 9 themes may be limited, and that is difficult to
specify such aspects of science clearly and unambiguously. Indeed, from an analysis
of the comments of the participants, it is clear that many felt that some of the ideas
presented in the theme summaries were intertwined and not resolvable into separate
propositions. This finding suggests, therefore, that, whilst the research process has
required the separation and resolution of these components in order to weight their
significance and import, it should not be taken to imply a consensus that they should
be represented and communicated in that manner.

Executive Summary

In addition, four of the themes failed to meet our criteria for inclusion by only a few
percentage points. As any criteria for consensus are to some extent arbitrary, we see
the data presented in this report not as indicating that some ideas are essential to the
curriculum and others are not, but as indicating a gradation of consensus about the
significance of various components to an account of science rather than any singular
definitive account.

To our knowledge, no other similar empirical study has been undertaken. The
evidence of the level of consensus we have found within the wider science and
science education community about the account of science that should be
communicated through formal science education removes one of the major
impediments to teaching about science. As several of the components of this account
are either absent from existing curricula, or given minimal treatment, the findings lend
support to the argument that school science needs to devote more time to teaching
about science and less time to details of the content of the scientific canon. This
research, therefore, provides a significant body of empirical evidence to buttress the
case for placing the nature of science and its processes of enquiry at the core rather
than the margins of science education.

This report presents the findings of an empirical study conducted, using a Delphi
technique, to answer the question ‘What should be taught to school students about the
nature of science?’ The study was one of four projects of a funded research network
involving the University of York, the University of Leeds, the University of
Southampton and King’s College London. The principal aim was to develop and
improve evidence-based practice in science education (EPSE) 1 . This work was
funded by the UK Economic and Social Science Research Council as part of the
Teaching and Learning Research Programme. As such, the study sought to provide
empirical evidence of what the ‘expert’ community engaged with communicating and
teaching science thought was important for the average citizen to understand about
science (as opposed to a knowledge of its content) by the end of their formal

The need for such a study was perceived to lie in the growing arguments for science
education to provide a more effective preparation for citizenship (American
Association for the Advancement of Science, 1993; National Academy of Science,
1995; American Association for the Advancement of Science, 1998; Millar &
Osborne, 1998). For, whilst there has been almost global acceptance that formal
science education is an essential component of every young person’s education, there
has been little attempt to develop a curriculum that is commensurate with such
systemic reforms. Rather, too often, science courses have been adapted from
curricula whose roots lie in programmes that were essentially conceived as
foundational studies for those who were to become the next generation of scientists.
However, the core status of science can be justified only if it offers something of
universal value to all, and not solely to the minority who will become the next
generation of scientists (AAAS, 1998, Millar and Osborne, 1998; Fensham, 2000).
Traditionally, school science has often given scant and largely tacit treatment to the
nature, practices and processes of science with the consequence that most pupils leave
school with naïve or limited conceptions of science (Driver, Leach, Millar, & Scott,
1996). Yet, it is knowledge about science which many have argued is essential for the
education of the future citizen (Fuller, 1997; Irwin, 1995; Jenkins, 1997; Millar,
1996). This aspiration is problematic, however, as contemporary academic
scholarship would suggest that the nature of science is a contested domain with little
consensus or agreement about a view of science that might be communicated in
school science (Alters, 1997; Laudan, 1990; Taylor, 1996). This study sought,
therefore, to test whether it was possible to find any consensus amongst the
community engaged with science communication about those aspects of the nature of
science that might be communicated successfully to school students.

The report is in three parts: The first section considers and reviews the many issues in
the burgeoning body of academic literature that surrounds the nature of science and its
teaching in school science; the second, and major part, presents the methodology of
this study and its findings; the third discusses the conclusions that can be drawn from
this work and their implications for the teaching of science..

    Further details of the other work of this project can be found on the web site

Teaching the Nature of Science

Part 1: Teaching the Nature of Science: Difficulties
        and dilemmas

1.1 Why teach the nature of science?
Science education attempts to wrestle with three conflicting requirements – what
Collins (2000) terms the horns of a trilemma. On the one hand (Collins’ first horn)
science education wants to demonstrate the tremendous liberatory power that science
offers – a combination of the excitement and thrill that comes from the ability to
discover and create new knowledge, the liberation from the shackles of received
wisdom, and the tremendous insights and understanding of the material world that it
offers. This emphasis is apparent in the arguments of the advocates of the Nuffield
courses of the 1960s where school science was to offer pupils the opportunity ‘to be a
scientist for a day’. More recently, it is can be seen in the aspirations of the American
educational reforms where it is explicitly stated that students at all grade levels
‘should have the opportunity to use scientific inquiry and develop the ability to think
and act in the ways associated with [scientific] inquiry’ (National Academy of
Science, 1995).

Yet its mechanism for achieving such an aim is to offer a dogmatic, authoritarian and
extended science education where students must accept much of what they are told as
unequivocal, uncontested and unquestioned (Claxton, 1991) – Collins’ second horn.
And it is only when they finally begin practising as scientists that the workings of
science will become more transparent. Moreover, the emphasis of science education
on foundational aspects such as the definition of current, the parts of the body or the
names of the planets and their order, rather than the major themes or explanatory
theories, such as the origin and evolution of the Universe or the evolution of the
species, means that any sense of the cultural achievement that science represents is
belittled. As the report Beyond 2000 states:

    We have lost sight of the major ideas that science has to tell. To borrow an architectural
    metaphor, it is impossible to see the whole building if we focus too closely on the
    individual bricks. Yet, without a change of focus, it is impossible to see whether you
    are looking at St Paul’s Cathedral or a pile of bricks, or to appreciate what it is that
    makes St Paul’s one the world’s great churches. In the same way, an over concentration
    on the detailed content of science may prevent students appreciating why Dalton’s ideas
    about atoms, or Darwin’s ideas about natural selection, are among the most powerful
    and significant pieces of knowledge we possess. (Millar & Osborne, 1998:13)

The outcome is that science education may, in a non-trivial sense, be science’s worst
enemy, leaving far too many pupils with a confused sense of the significance of what
they have learnt and, more seriously, a potentially enduring negative attitude to the
subject itself (Osborne & Collins, 2000; Osborne, Driver, & Simon, 1996). Such an
outcome, whilst regrettable, does little harm to the traditional education of the future
scientist – which demands a lot of routine and rote learning to acquire the basics of
the domain. In fact, much of traditional science education can be seen as a test of an
individual’s ability to sustain endeavour when confronted by the weight and authority
of scientific knowledge and its difficulty and complexity – a quality which is an
essential requirement for the professional scientist.

Teaching the Nature of Science

An inevitable outcome, however, is that such an education ignores or neglects the
third horn of Collins’ trilemma, the requirement to provide its students with some
picture of the inner workings of science – knowledge, that is, of science-in-the-
making (Latour, 1985). Such knowledge is essential for the future citizen who must
make judgements about reports about new scientific discoveries and applications of
scientific knowledge. Contemporary society, it is argued (American Association for
the Advancement of Science, 1989; Jenkins, 1997; Jenkins, 1998; Millar, 1996; Millar
& Osborne, 1998), requires a populace who have a better understanding of the
workings of science that enables them to engage in a critical dialogue about the
political and moral dilemmas posed by science and technology, and arrive at
considered decisions. Informed use by citizens and society of new developments in
science will, for instance, require the ability to judge whether an argument is sound,
and to differentiate evidence from hypotheses, conclusions from observations and
correlations from causes.

Another imperative driving the need to teach more about science is the growing
influence of science and technology on our society. For science and technology pose
questions which seem to require complex and specialised knowledge that only an elite
possess. Yet a core commitment of democratic Western societies is the principle that
all people should be able to contribute to the making of significant decisions (Nelkin,
1975) – essentially that the plurality of voices matters regardless of expertise. As the
European White Paper on Education and Training (1995) argued:

    ..this does not mean turning everyone into a scientific expert, but enabling them to fulfil
    an enlightened role in making choices which affect their environment and to understand
    in broad terms the social implications of debates between experts. There is similarly a
    need to make everyone capable of making considered decisions as consumers. (p28)

Within science education, the response has been to argue for a curriculum that
recognises the need to prepare pupils to engage critically with such issues,
recognising both the strengths and the limitations of science. Millar, for instance, sees
one of the major purposes of science education as ‘equipping students to respond to
socio-scientific issues’ and that ‘this requires an understanding of the nature of
scientific knowledge’ (Millar, 1997:101). In the same volume, both Millar and
Jenkins (1997) suggest that pupils should be provided with some insight into the
difficulty of generating reliable and consensual understanding of the natural world.
Likewise, Driver et al. (1996) argue that:

    Some explicit reflection on the nature of scientific knowledge, the role of observation
    and experiment, the nature of theory, and the relationship between evidence and theory,
    is an essential component of this aspect of understanding of science. (Driver et al.,

Further doubt is cast on the appropriateness of the traditional emphasis on content
knowledge in science education for the majority of young people by evidence that the
knowledge acquired has an evanescent quality. A number of well-funded surveys
have been conducted in the UK (Durant, Evans, & Thomas, 1989), Europe (Miller,
Pardo, & Niwa, 1997) and the United States (Miller, 1995). These surveys used a mix
of closed questions, true-false quizzes containing items such as ‘Is it true that:– ‘lasers
work by focussing sound waves?’, ‘All radioactivity is man made?’, ‘Antibiotics kill
viruses as well as bacteria’, and open questions. A few of the results from one such

Teaching the Nature of Science

survey are shown in Table 1. Whilst such findings might be similarly true for the
public understanding of great literature, they suggest that such knowledge, if it ever
existed, is simply lost through lack of reinforcement or use. Furthermore, such data
invite the question of what is the function of science education if so much of its
product, for most people, has such an ephemeral quality?

                                                                             Europe       United States
                                                                              1992            1995
                                                                                %               %
Disagree that “Antibiotics kill viruses as well as bacteria”                    27              40
Indicate that the Earth goes around the Sun through a pair of closed            51              47
Disagree that “radioactive milk can be made safe by boiling it”                 66              61
Agree that “electrons are smaller than atoms                                    41              44

 Table 1: Percentage of individuals giving specific responses to questions used to determine the
                    public knowledge of scientific concepts (Miller, 1998).

Durant, Evans and Thomas’ (1989) work also examined the public’s understanding of
the process of scientific enquiry. Whilst more than 50% could identify basic
methodological processes necessary for testing new drugs, and interpret the
implications of probabilistic statements about inheritance, less than 50% were able to
identify the theory of relativity or Darwin’s theory as ‘well-established explanations’,
choosing instead ‘a proven fact’ as the best description. In this case at least, the lack
of understanding can possibly be ascribed to a failure of traditional science education
to teach the meta-language of science.

Coupled with the changing nature of contemporary society, the outcome of such
findings has led to a consideration of what other forms of knowledge and
understanding, in addition to content knowledge, science education should seek to
develop. Foremost in the literature have been arguments for a greater emphasis on the
nature of science and its social practices, and evaluative criteria for judging both its
practice and its products.

1.2. Arguments for Teaching about the Nature of Science
Whilst knowledge of science entails knowledge of the scientific facts, laws, theories –
all of which can be seen as the products of canonical science – it also entails
knowledge of the processes of science and its epistemic base. Matthews (1994) points
elegantly to the latter as the missing dimension of science education arguing that:

     To teach Boyle’s Law without reflection on what “law” means in science, without
     considering what constitutes evidence for a law in science, and without attention to who
     Boyle was, when he lived and what he did, is to teach in a truncated way. (Matthews,

Likewise, Ogborn (1988) has argued that science education should consider questions
of what is (the ontological question), how we know (the epistemological question),

Teaching the Nature of Science

why it happens (the causal question), what we can do with it (the technological
question), and the communicative question (how we should talk about science). The
overemphasis on the first of these questions at the expense of the others, particularly
the issue of ‘how we know what we know’, results in a science education which too
often leaves students only able to justify their beliefs by reference to the teacher or
textbook as an authority. Horton (1971) makes the telling point that such practice
made the child of the developed Western World no different from the young child in
the developing world as, in both cases, their teachers were deferred to as the
accredited agents of tradition. Any science education which focuses predominantly
on the intellectual products of scientific labour – the ‘facts’ of science – offers,
therefore, only a partial view of science. Moreover, it leaves students, when
confronted by new scientific claims, without a functional understanding of the
processes and practices necessary to evaluate the claim. And, if science and
scientists, as some would wish to claim, are epistemically privileged, it is at best
ironic, and at worst an act of ‘bad faith’ that the science education we offer does little
to justify or explain why science is considered the epitome of rationality (Osborne,
2001). Rather, the failure to teach about science ‘runs the risk of producing students
who do not even perceive science as rational’ (Duschl, 1990).

The contemporary significance of socio-scientific issues has also led to arguments
that school science is an appropriate context for the consideration of issues of an
ethical nature (Newton, 1988; Reiss, 1993; Reiss, 2000). For, whilst school science
education often seeks to marginalise and keep technology at a distance (Hughes,
2000), such a separation is not one that either the public or students recognise (Irwin,
1995). And, since the funding, application and use of science all involve ethical and
value-based decisions, ethics are ‘inevitably and inexorably conflated with science in
most cases’ (Reiss, 2000). Fuller (1997:9) would go further, arguing that ‘most of
what non-scientists need to know in order to make informed public judgements about
science falls under the rubric of history, philosophy, and sociology of science, rather
than the technical content of scientific subjects.’ Whilst such views are contested by
those who would argue that the fundamental character of science is reductionist,
value-free and non-reflexive (Donnelly, 2000), evidence would suggest that divorcing
the teaching of science from the social and technological context of its application is
simply, for must pupils, an unreal and false dichotomy diminishing its relevance and
appeal to pupils (Osborne & Collins, 2000).

Another imperative driving the arguments for greater attention to the nature of science
is the major structural reforms that have occurred in science education globally. The
growing reliance of contemporary societies on science has led to a near universal
acceptance of the argument that science education should be ‘for all’ and compulsory
(Fensham, 2000), as it is in the UK from age 5 to 16. Yet, as Millar and Osborne
(2000:195) argue, the only way that the core and compulsory status of science
education can be justified is ‘if the form of science taught can seen to be, providing
something of universal value that every young person needs in later life.’

Faced, however, with the task of centrally defining a curriculum for all, policy makers
have predominantly retained the traditional approach to science education and added
marginal elements about the nature of science without much ‘sense of coherence and
underlying educational purpose’ (Donnelly, 2001). The outcome has been curricula
which are still dominated by content with only scant attention paid to teaching about

Teaching the Nature of Science

science and its history, philosophy and practices. Consequently, as Monk and
Osborne (1997) have argued, the history and philosophy of science will continue to
remain more talked about than taught as long as the assessment of science continues
to focus on the its content rather than the methods and practices of science.

The marginalization or non-existence of the nature of science in science education
does not mean, however, that children will emerge with no conceptions about the
nature of science (Nadeau & Desautels, 1984). For the sin of omission – ‘giving
insufficient thought and attention to the nature of scientific knowledge and the
conditions under which it has been developed’ – simply reinforces a scientistic
ideology which Nadeau and Desautels see as a blind faith in the cognitive and moral
value of science. Science teachers do not serve simply as purveyors of a store of
theoretical knowledge but as a means through which scientific activity is legitimised
and given value. Thus, whilst they may think that they are only teaching the content
of science, they are implicitly communicating ideas about the nature of science and
scientists which may be fallacious. The consequence is that too often science comes to
be seen as a ‘final-form’ product with immutable and definitive qualities (Duschl,
1990; Driver et al., 1996) when, in reality, scientific knowledge is often modified,
adapted, or even at times, abandoned. School science, residing solely in the context
of justification rather than the context of discovery, simply fails to convey that
controversy or argumentation are a normal feature of science (Driver, Newton, &
Osborne, 2000; Gross, 1996). Consequently pupils and the future public are
perplexed by the failure of scientists to agree on issues raised by science-in-the-
making such as the existence of global warming, the transmission of BSE or the effect
of genetically modified organisms on the environment.

Even the manner in which science is reported and communicated to other scientists,
let alone the public, is a misrepresentation of its practice. For scientific writing
excises the confusion, doubt, and blind alleys – presenting its findings as the linear
and formulaic application of a standard method which lead inexorably to its inevitable
conclusions (Gross, 1996; Medawar, 1979).

Many would argue that the current form of science education is sustained by a set of
arcane cultural norms – ‘values that emanate from practice and become sanctified
with time’ and that ‘the more they recede into the background, the more taken for
granted they become’ (Willard, 1985). Such cultural norms are distinguished from
other rules, not by reference to any lack of authority, but rather by the unconscious
force they exert over human actions. Milne and Taylor (1999) characterise such
norms as myths – narrative accounts of collective experience – where the ‘historical
and contingent quality of established patterns and beliefs and practices is replaced by
an unwarranted sense of naturalness and inevitability.’ One consequence of this is
that the knowledge becomes tacit and the supporting evidence ‘invisible’ (Barthes,
1972). Hence, the standard view or collective myth within science teaching, is that
explicit consideration of the nature of science is not required because it is implicitly
incorporated and diffused throughout all contexts.

Abd-el-Khalik and Lederman (2000) make the important point that such approaches
to teaching the nature of science that assume it can be acquired implicitly, through a
process akin to osmosis, is naïve. For the various images of science that have been
constructed by the historians, philosophers and sociologists of science are the product

Teaching the Nature of Science

of considerable collective and reflective endeavour. Just as nobody would expect a
student to rediscover Newton’s laws by observing moving objects, neither should we
expect students to come to an understanding of science’s nature simply by engaging
in scientific practice. The nature of science, therefore, must be explicitly taught as
much at its content.

Moreover, research would suggest that implicit approaches to teaching the nature of
science develop notions that scientific facts or laws are derived unambiguously from
empirical evidence; that scientific ideas are unequivocal and absolute; and that
scientists predominantly work in isolation in laboratories ‘discovering’ new
knowledge (Mead & Métraux, 1957; Driver et al., 1996). And, as McComas (1998)
points out, there is substantive evidence that such a science education generates, or
fails to confront, the following ‘myths’ about science – each of which has been
challenged by contemporary scholarship 2 .

        1.     Hypotheses become theories that in turn become laws
        2.     Scientific Laws are absolute
        3.     A Hypothesis is an educated guess
        4.     A general scientific method exists which is applied universally
        5.     Evidence accumulated carefully will result in sure knowledge
        6.     Science and its methods provide absolute proof
        7.     Science requires the procedural application of standard routines rather
               than creative thought
       8.      Science and its methods can answer all questions
       9.      Scientists are particularly objective
      10.      Experiments are the sole routes to scientific knowledge
      11.      All scientific data are reviewed for accuracy
      12.      Acceptance of new scientific knowledge is straightforward
      13.      Science models correspond accurately with reality
      14.      Science and technology are identical
      15.      Science is a solitary pursuit

McComas’ analysis leads him to conclude that ‘it is vital that the science education
community provide an accurate view of how science operates to students and by
inference to their teachers.’ The corollary of this statement is the necessity for the
scholarly community to define what an ‘accurate view of how science operates’ is
and, furthermore, how should it be taught? Both of which are questions central to the
concerns of this research.

There are, nevertheless, caveats about expecting too much of the science curriculum
or science teachers. Harding and Hare (2000) argue that the arguments of McComas
and others ask science teachers to wrestle both with teaching well-established
consensually agreed knowledge and, in addition, showing that some scientific
knowledge, especially when it is first produced, can be tentative. Science teachers
commonly use the notion of ‘truth’ to describe knowledge that is uncontested and
widely accepted. Their intent is not an assertions about any correspondence with

     The strongest challenge to these ideas is to be found in the work of the sociologists of science –
     see for instance the work of: (Collins & Pinch, 1993; Fuller, 1997; Latour & Woolgar, 1986) and
     in the work of those engaged in the study of science from a rhetorical perspective:
     (Gross, 1996; Taylor, 1996).

Teaching the Nature of Science

reality but merely a statement about a reliable and consistent interpretation of the
material world. To ask, then, that they also suggest that scientific knowledge is
tentative will undermine the world-view in which the science teacher resides.
Osborne (2001), from a rhetorical perspective, goes further, arguing that teachers are
engaged in a process of persuading pupils of the validity of the scientific world-view.
Asking them to suggest that not all knowledge is certain and unequivocal will damage
their primary rhetorical task. And, if, as Kuhn (1999) argues, most children are
absolutists believing that all assertions can be checked and shown to be either false or
true until adolescence, they may be psychologically ill-prepared to deal with a subject
that does not offer certain knowledge.

Nevertheless, the underlying fallacy of Harding and Hare’s arguments is that they are
based in a broad acceptance of science education as it is and not as it might be. If
science education is to be solely a preparation for future scientists (a view with which
we do not concur) then there may be little place for exploring the distinction between
tentative and well-established knowledge, how such distinctions are drawn, how
evidence is evaluated, or the meta-language that is used to describe science.
Moreover, we ourselves, also feel that the formal education of scientists and their
work would benefit from a more systematic exploration of the nature of the work that
they are engaged in and its historical development. However, sixty years after
Haywood (1927) developed a strong case for teaching the nature of science,
secondary science education is still in much the same position as it was then, as
evidenced by the need for Matthews’ (1989; 1994). Duschl’s (1990) and Hodson’s
(1993) careful cases for the place of history and philosophy of science (HPS) in
science teaching. What then are the pitfalls and obstacles that have blocked the
inclusion of the nature of science in the curriculum?

1.3. Why has incorporating NOS in the school curriculum
     been a failed project?

1.3.1     The history of science in school science
Given the considerable attention devoted to exploring the significance and relevance
of the history, philosophy and nature of science, it remains somewhat of a puzzle,
therefore, that its consideration has remained such a marginal feature of most
mainstream science education courses. Perhaps the simplest and most telling
explanation is Kuhn’s (1970) observation that the history of the subject is of no
import to the education of the future scientist. For the potential scientist must acquire
an understanding of the basic concepts and foundations of the discipline as it is not as
it was. His or her concern is investigating the questions about nature that remain
extant, not exploring how others have answered their own questions – answers which
are now well understood and consensual knowledge within the scientific community.
Taking from the past, therefore, is only of value if it offers something which is of
significance to the present.

Even the epistemological question of how such knowledge was unearthed is of little
value, as the concerns of today are rarely the concerns of yesteryear, and
contemporary methodological tools and procedures have made earlier techniques

Teaching the Nature of Science

irrelevant. For the interdependent relationship between science and technology leads
to new technologies which open new windows and approaches to enquiry. Thus the
chemical determination of composition by assaying and weighing is replaced by the
techniques offered by infrared, Raman and mass spectrometry. Visible wavelength
telescopes become just one of a plethora of different means of observing the universe,
from long baseline radio interferometry to X-ray satellites. Whereas biology was a
science concerned with the study of living organisms and their classification, it has,
instead, become a science dominated by molecular biology and genetic determinism.
Even a small field of enquiry devoted to the search for gravitational waves has moved
on from the use of large aluminium bars to long base line interferometers. Given such
substantive methodological changes, the history of science offers few insights, if any,
into how the scientist of today should proceed. The glittering prizes that science
offers will not be won by redeploying yesterday’s technology but through the
invention of innovative approaches to questions that emerge from a good
understanding of the discipline as it is, not as it was.

A different argument is advanced by Brush (1969) in a seminal article entitled
‘Should the History of Science be rated X?’ Brush’s thesis is that much conventional
teaching about the history of science is neither good science nor good history. It is
not good science, as taking from the past is only of value if it offers something which
is of significance to the present – which it rarely does. Moreover, it is not good
history, as the myths and anecdotes that feature in science textbooks commonly
reinforce a ‘Whig’ interpretation of the history of science which presents the past in
terms of present ideas and values, elevating in significance all incidents and work that
have contributed to our current understanding, rather than attempting to understand
the social context and the contingent factors which were significant to its production.
For example, very crudely the Whig view would portray Fleming’s discovery of
penicillin as the brilliant perception of an exceptional scientist of a fortuitous event.
A more realistic account would demonstrate that it was contingent on (a) problems of
current interest in medical research and Fleming’s existing bacteriological research
interests, (b) the weather at the end of July in 1928 which happened to be sufficiently
cool to allow the mould to grow, and (c) the presence of a laboratory beneath which
was investigating moulds – and that even then, its beneficial application was delayed
for ten years before other researchers explored ways of producing the mould in
commercial quantities. Practically without exception, science texts are simply not
written with the intent to convey any of the latter type of information on the context of
discovery which the professional historian of science would consider essential. Brush
argues that the failure to teach history appropriately may inhibit the development of a
critical mind by presenting ‘the present as the inevitable, triumphant product of the
past.’ Since science education is an attempt to cultivate scepticism towards all
dogmatic and singular interpretations of events, such a simplistic approach to the
teaching of its own history would run counter to one of its essential aims.

1.3.2. The context of science education
Reichenbach’s (1938) distinction between the context of historical discovery and the
context of epistemological justification offers some insight into why HPS is often
ignored in school science. In the context of discovery, ideas are tentative, if not
speculative, and presented in language which is interpretative and figurative (Sutton,
1995), often using new metaphors (Eger, 1993). The central concern of most science

Teaching the Nature of Science

teachers, in contrast, is the transmission of the products of ‘the context of
epistemological justification’ - that is a narrow focus of ‘what we know’ rather than
‘how we know’. Gallagher (1991), in looking at prospective and practising secondary
school science teachers’ knowledge and beliefs about the philosophy of science,
provides a recent reminder that, for its teachers, science is perceived as an established
body of knowledge and techniques which require minimal justification. Such teachers
often work from weak evidence, use inductive generalisations (Harris & Taylor,
1983), and renegotiate classroom observations and events to achieve a social
consensus (Atkinson & Delamont, 1977), persuading their pupils of the validity of the
scientific world-view (Ogborn, Kress, Martins, & McGillicuddy, 1996). Gallagher
comments that, even if science teachers consider the history of science for inclusion in
the curriculum, it is generally only in terms of humanising science for the purpose of
fostering positive attitudes to science, rather than for the purpose of understanding the
nature of science. For many teachers of science, only the development of an
understanding of science concepts and the nature and methods of science are essential
to an education in science. The rest lies beyond the boundary of ‘what we now
know’, which, as Haywood recognised in 1927, is the criteria that curtails science
teachers’ incorporation of HPS into their schemes of work.

1.3.3. The nature of science teachers
Another fundamental difficulty identified by a variety of authors is that many science
teachers, themselves the products of such an archetypal education, are invariably left
with a range of misconceptions or naïve understandings of the nature of science.
Various authors have argued, with respect to content knowledge, that one of the
necessary conditions of effective teaching is a good knowledge and understanding of
the content to be communicated (Shulman, 1986; Osborne & Simon, 1996; Turner-
Bissett, 1999). Likewise, it follows that teaching about the history, philosophy and
nature of science requires a good knowledge and understanding of the body of
scholarship that exists about these subjects.

Consequently, during the past 15 years there have been several attempts to ascertain
the extent, depth and nature of science teachers’ knowledge and understanding about
the nature of science (Brickhouse, 1991; Hodson, 1993; King, 1991; Kouladis &
Ogborn, 1989; Lederman & Zielder, 1987; Mellado, 1998). The main picture to
emerge from this research is that science teachers have no consistent view about the
nature of science and that, in the light of contemporary scholarship, most of views
they hold could be termed ‘inadequate’ (Abd-El-Khalick & Lederman, 2000). A
significant proportion of teachers, for instance, have no recognition of the tentative
nature of some scientific knowledge and others hold positivist or empiricist views of
the nature of science. Koulaidis and Ogborn (1989) also found distinctions between
teachers from the separate scientific disciplines and that student teachers hold
somewhat different views from those of experienced teachers. Moreover, several
studies have now consistently shown that there is little relationship between teachers’
declared conceptions of the nature of science and the manner in which they present
the subject in the classroom (Brickhouse, 1991; Duschl & Wright, 1989; Hodson,
1993; Lederman & Zielder, 1987). The best explanation for this finding would appear
to be that teachers’ actions are dominated by the exigencies and imperatives of
managing classroom learning and not their own philosophical stance towards science.
Coupled with the eclectic and heterogeneous nature of teachers’ views, it is perhaps

Teaching the Nature of Science

not surprising that incorporating more of the nature of science into the curriculum is
seen as a substantial task. For the findings of these studies invite the questions of
whether a) it is possible to establish amongst the science education community some
common consensual understanding about the salient and significant features of the
nature of science that should be communicated to students, and b) whether it is then
possible to teach this understanding effectively.

1.3.4. The contested nature of science
Abd-el-Khalick and Lederman (2000) argue that the body of work on teachers’
conceptions of the nature of science simply shows a failure of science teachers’ own
education to develop a ‘valid understanding of NOS’. But what would such a valid
understanding be? The one feature that emerges from an examination of the
scholarship in the field of history and philosophy of science is that, if its intent was to
establish a consensual understanding of the foundations of the practice of science,
then it might be best characterised as a ‘failed project’ (Taylor, 1996). Baconian
notions of science as a process of empirical observation and inductive generalisation
have always been open to the criticism that no singular set, or sets of data, can
establish that any generalisation is universally true. The logical positivists attempted
to take this further by demanding that all statements were either logically deducible or
verifiable by observation, anything else being mere speculation, thereby offering a
means of proving the truth of scientific statements. However, the weakness of this
position was perhaps best illustrated by Mach’s use of it to deny the atomic
hypothesis. Popper’s work on conjecture and refutation shifted the emphasis from
verification to falsification, and was a significant change in focus in developing our
understanding of how science proceeds by arguing that scientists are engaged in the
endeavour of trying to refute rather than prove theories. However, this view, in turn,
is subject to the criticism that the historical record shows that scientific theories are
not abandoned simply because of one observation which does not fit and, furthermore,
that scientists do not strive to falsify their theories. Lakatos offered a significant
development of Popper’s ideas by suggesting that scientists work with an inner core
of basic assumptions or theories, and that these are surrounded by a ‘protective belt’
of auxiliary hypotheses or assumptions. Only data that directly contradicts the
theoretical and empirical assumption that contribute to the hard core of working
theories are capable of challenging well-established ideas.

However, it is perhaps to Thomas Kuhn (1962), and his interest in what the historical
record had to say about the practice of science, that we owe the greatest revolution in
our understanding of the nature of science. Kuhn’s work distinguished between
periods of normal science, in which there is a set of basic commonly-agreed
assumptions about theory and methods, and scientific revolutions when all the
fundamental assumptions of a given field were questioned, precipitating a crisis.
Kuhn’s incidental achievement was to shift the focus from the nature of the
knowledge itself to the means by which it was produced as a social community. One
result was an explosion and growth of work in the field of the sociology of scientific
knowledge (SSK) (Bloor, 1976; Feyerabend, 1975; Gross, 1996; Latour, 1993; Latour
& Woolgar, 1986; Taylor, 1996; Traweek, 1988). This programme of work was
notable for its interest in the causes of beliefs, that is the means by which the
scientific community were persuaded of the validity of a scientific argument, rather
than the belief itself, and in addition, its strongly relativist view of the nature of

Teaching the Nature of Science

scientific knowledge. Arguably, its major achievements were to establish that there is
no such thing as a singular scientific method and that scientists are engaged in a
process of rhetorical argumentation within a social community. And, like all social
communities, science has well-established codes of conduct and norms of practice by
which the status of individuals and their work is judged. The other major
achievement of SSK has been to problematise the nature of science even further,
leading to the conclusion asserted by Laudan et al. (1986:142) that:

    the fact of the matter is that we have no well-confirmed general picture of how science
    works, no theory of science worthy of general assent.

Further evidence for a lack of consensus comes from the work of Alters (1997) who
surveyed the views of 210 members of the U.S. Philosophy of Science Association.
Using a questionnaire containing 15 basic tenets about the nature of science drawn
from the literature, and which the initial pilot had suggested were controversial, Alters
was forced to conclude from the 187 responses that:

    A minimum of 11 fundamental philosophy of science positions are held by philosophers
    of science today……The implication for the science education research community and
    its formal organisation is that we should acknowledge that no one agreed-on NOS
    exists. (p 48)

Faced with a lack of consensus within the discipline, Alters argues that the only
legitimate position for the science education community is to adopt a pluralistic
approach to teaching about the nature of science. However, Smith et al. (1997) make
the not unreasonable point that these findings are hardly surprising, given that the
statements were selected on the basis that they would be likely to produce
controversy. Even then, 75% of the respondents agreed with 6 or more of the
statements, even though as philosophers they are professionally trained to argue. A
different response might have been obtained from a broader community – something
which this present study attempts to do. More significantly, an analysis of eight
curriculum standards documents such as the Benchmarks for Scientific Literacy,
National Science Standards, the California State Standards, and National Curricula in
Australia, New Zealand, Canada, and England and Wales have shown that there does
exist some consensus within science education community about the elements of the
nature of science that should be taught (McComas & Olson, 1998). McComas and
Olson summarise these as:

   a. Scientific knowledge while durable, has a tentative character.
   b. Scientific knowledge relies heavily, but not entirely, on observation
      experimental evidence, rational arguments, and scepticism.
   c. There is no one way to do science (therefore there is no universal step-by-step
      scientific method.
   d. Science is an attempt to explain natural phenomena.
   e. Laws and theories serve different roles in science, therefore students should
      note that theories do not become laws even with additional evidence.
   f. People from all cultures contribute to science.
   g. New knowledge must be reported clearly and openly.
   h. Scientists require accurate record keeping, peer review and replicability
   i. Observations are theory-laden.
   j. Scientists are creative.

Teaching the Nature of Science

     k. The history of science reveals both an evolutionary and a revolutionary
     l. Science is part of social and cultural traditions.
     m. Science and technology impact on each other.
     n. Scientific ideas are affected by their social and cultural milieu.

Insofar as some or all of these tenets might be contentious within the philosophical
community, it is possible to argue that they represent a partial or simplified view of
the nature of science. However, in that they represent elements that the community
considers important aspects of people’s ideas about science, they represent legitimate
aspirations for the curriculum. Science education has, after all, commonly relied on
vulgarised or simplified accounts of its content as pedagogical heuristics for
communicating a basic scientific understanding. Thus the Bohr model of the atom is
still taught although it has been superceded by quantum models within the scientific
community. Likewise, initial encounters with the explanations for energy, the
transistor or glycolis metabolic pathways are three examples amongst the many of the
vastly simplified accounts of our full understanding that science education offers its
students. They are used simply because they offer a vital first step and preliminary
introduction to a fuller understanding. Alters’ position, however, in common with
that of Rudolph, is to argue that science education should avoid such simplifications
and, rather, to offer plural accounts of its varied nature grounded in particular

Our basic premise in this work has been to question such a position. For, if we are to
ask science teachers to teach explicit aspects of the epistemic nature of science, then
as a community, we must come to some agreement about what those aspects might be
(Duschl, Hamilton, & Grandy, 1990). Our approach, then, in this research, has been
to seek to establish empirically whether there is significant support within the expert
community for an account of the nature of science that might be offered to school

Part 2: Methodology and Findings

2.1. Methodology
This project sought to determine what might constitute the learning targets for the
processes and practices of science for pupils aged 5-16 and, in addition, what might be
the justifications for such targets. In approaching this task, our decision was to adopt the
Delphi method (Dalkey & Helmer, 1963). Essentially this is a research tool for
establishing consensus among experts in any given field and, whilst widely used in the
social sciences, it has been relatively underused in education. This qualitative research
approach facilitates the systematic elicitation and analysis of the judgements of a panel of
experts within a common field. Issues are explored through multiple iterations or rounds
of questionnaires which provide summarised statistical information and written responses
from previous rounds – all of which encourages feedback and comment by the
participants on the panel (Delbecq et al., 1975; Cochran, 1983; Dailey & Holmberg,

Whilst the Delphi method has long been utilised for forecasting future trends by
government and industry, the technique has proved so successful in producing consensus
that it has outgrown its use solely in forecasting. It is now adopted in a range of
situations, including social science research, where convergence of opinion is desirable
(Murry & Hammons, 1995). The evolution of the Delphi method has resulted in the
development of three distinct forms. First, the ‘exploratory Delphi’ – most closely
associated with that developed by the Rand Corporation in the 1960s as a forecasting
methodology – which elicits expert opinion about the probability, desirability, and impact
of future events. Second, the ‘focus Delphi’, seeks the views of disparate groups that are
likely to be affected by a projected programme or policy. The third form, the ‘normative
Delphi’, gathers the opinions and views of a defined group of experts on clearly specified
issues, with the aim of achieving consensus (Dailey& Holmberg, 1990). In education the
normative Delphi has been utilised effectively for issues pertaining to the generation of
educational goals and objectives (Helmer, 1966; Adelson, 1967), and curriculum
planning and development (Judd, 1971; Häussler et al., 1980; Martorella, 1991; Petrina,
1992; Smith and Simpson, 1995). The strength of the Delphi method in addressing such
issues lies in the principle that ‘several heads are better than one’ (Weaver, 1971) in the
decision making process. Thus the outcomes have greater validity than those propounded
by an individual. The anonymity of participants in a Delphi study alleviates the
drawbacks commonly associated with group interviews in reducing specious persuasion,
deference to authority, impact of oral facility, reluctance to modify publicised opinions,
and the bandwagon effect of majority views (Helmer & Rescher, 1960; Martorella,
1991). The Delphi method also makes it possible to elicit opinions from a group of
experts who are geographically dispersed (Murry & Hammons, 1995). The value of the
normative Delphi in encouraging agreement by experts on a range of issues made it a
potentially useful tool for identifying and prioritising key ‘ideas-about-science’ to be
included in the school science curriculum for pupils up to age 16 – an area in which any
consensus is not well established (Part 1).

Methodology and Findings

Each successive round of a normative Delphi study is designed to move participants
towards consensus. The Delphi procedure typically ends after either consensus or
stability of responses has been achieved. Brooks (1979) identified consensus as ‘a
gathering of individual evaluations around a median response, with minimal divergence’.
Stability or convergence were said to be reached when ‘it becomes apparent that little, if
any, further shifting of positions will occur’ (ibid). The number of rounds for a Delphi
study will be determined by how expeditiously the panel attains consensus and/or
stability. However, for pragmatic reasons, many Delphi studies restrict themselves to
three rounds and, as in this case, examine what, if any, is the emergent consensus at the
end of the third round. Hence, for such reasons of cost and time, a three-round Delphi
inquiry was chosen to ascertain the extent to which consensus exists among experts
within the science community about the learning targets for the processes and practices of

2.1.1. Procedures for the Study
The number of participants in any Delphi study is determined by the nature and scope of
the issue to be addressed. Typically, panels comprise a minimum of ten individuals,
although reliability improves and error is reduced in direct relation to an increase in the
number of participants (Cochran, 1983). However, Delbecq et al (1975) maintained that
few new ideas are generated within a homogeneous group once the number exceeds thirty
well-chosen individuals.

For this study members of the Delphi panel of experts were selected to represent a
community engaged in the practice, articulation and/or communication of science.
Individuals from five areas within this community were recruited to the study:

     •   Research scientists, eminent in their field;
     •   Prominent philosophers and sociologists of science renowned by their work and
     •   Leading individuals engaged in science communication in the UK
     •   Leading science educators who have played a significant role in developing or
         implementing existing curricula;
     •   Science teachers recognised as experts through teaching awards or recognition
         as ‘advanced skills’ teacher.

An additional criterion for the first three groups was that individuals had a recognised
interest in science education. For the last two groups, we also attempted to ensure that
individuals had a spread of expertise between primary and secondary phases of school
science education. A letter was sent to prospective members of the panel, summarising
the aims and purposes of the project, and outlining the tasks, procedures and approximate
time commitment for the three rounds of the Delphi study. A total of 25 individuals was
selected and 23 of these completed all three rounds of the study.

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