Relevant Research on the Nature of
Science and Assessment Tools
Learning and Teaching of the Nature of Science in School
In the science education literature, NOS typically refers to the epistemology
and sociology of science, or the values and beliefs inherent in scientific
knowledge and its development (Lederman,
1992;
Ryan & Aikenhead,
1992).
Whereas there are still many disagreements about NOS among
philosophers, historians, sociologists and science educators, research has
shown that consensus does exist regarding the basic aspects of NOS most
relevant to school science curricula (e.g.,
McComas
& Olson,
1998;
Osborne, Collins, Ratcliffe, Millar, &
Duschl,
2003).
For instance, Osborne et al. (2003)
conducted a
Delphi
study to determine the extent of consensus on teaching NOS topics in school as
perceived by a group of acknowledged international experts including science
educators, scientists, historians, philosophers, and sociologists of science.
This expert community reached a consensus on the following NOS themes:
Scientific Methods and Critical Testing, Creativity, Historical Development of
Scientific Knowledge, Science and Questioning, Diversity of Scientific
Thinking, Analysis and Interpretation of Data, Science and Certainty, and
Hypothesis and Prediction. The ninth theme of consensus was on "Cooperation
and Collaboration," although it was found to be less stable than the others.
Moreover, in an analysis completed by McComas and
Olson (1998),
similar themes are also consistently highlighted in the national science
curriculum standards documents from different countries.
In light of the abovementioned studies, we chose to focus our research on the
following essential, non-controversial components of the nature of scientific
knowledge development (Lederman,
Abd-El-Khalick,
Bell,
& Schwartz,
2002).
These aspects have been emphasized in the aforementioned science education
reform documents, and have been widely discussed in the NOS empirical studies
(e.g., AAAS,
1990,
1993;
Aikenhead & Ryan,
1992;
Chen,
2006;
Kuhn,
1970;
Lederman, Abd-El-Khalick,
Bell,
& Schwartz,
2002;
Lederman,
2004;
McComas & Olson,
1998;
National Science Teachers Association,
2000):
-
Tentativeness of Scientific Knowledge: Scientific
knowledge is both tentative and durable. Scientific knowledge is reliable;
however, it may be abandoned or modified in light of new evidence or
reconceptualization of existing evidence and
knowledge. The history of science reveals both evolutionary and revolutionary
changes.
-
Observations and Inferences: Science is based on both
observations and inferences. Both observations and inferences are guided by
scientists' prior knowledge and perspectives of current science. Multiple
perspectives can lead to multiple valid inferences.
-
Subjectivity and Objectivity in Science: Science aims to
be objective and precise, but subjectivity in science is unavoidable. The
development of questions, investigations, and interpretations of data are to
some extent influenced by the existing state of scientific knowledge and the
researcher's personal factors and social background.
-
Creativity and Rationality in Science: Scientific
knowledge is created from human imaginations and logical reasoning. This
creation is based on observations and inferences of the natural world.
Scientists use their imagination and creativity throughout their scientific
investigations.
-
Social and Cultural Embeddedness in Science:
Science is part of social and cultural traditions. People from all cultures
contribute to science. As a human endeavor, science is influenced by the
society and culture in which it is practiced. The values and expectations of
the culture determine what and how science is conducted, interpreted, and
accepted.
-
Scientific Theories and Laws: Both scientific laws and
theories are subject to change. Scientific laws describe generalized
relationships, observed or perceived, of natural phenomena under certain
conditions. Theories are well-substantiated explanations of some aspect of the
natural world. Theories do not become laws even with additional evidence; they
explain laws.
-
Scientific Methods: There is no single universal
step-by-step scientific method that all scientists follow.
Scientists investigate research questions with prior knowledge, perseverance,
and creativity. Scientific knowledge is constructed and developed in a variety
of ways including observation, analysis, speculation, library investigation
and experimentation.
Assessment of the Nature of Science
In the last decades, both quantitative and qualitative questionnaires have
been developed and used in conducting NOS related research. Examples of
traditional quantitative instruments include the Test on Understanding Science
(Cooley & Klopfer,
1961),
Science Process Inventory (Welch,
1966),
Nature of Science Scale (Kimball,
1967),
Nature of Scientific Knowledge Scale (Rubba,
1977),
and Modified Nature of Scientific Knowledge Scale (Meichtry,
1992).
These instruments contain multiple-choice or
Likert-type questionnaires and were usually
written from perspectives of experts. Jungwirth
(1974)
and Alters (1997)
criticized that those experts did not adequately represent perspectives of
scientists, philosophers, and science educators. Moreover,
items on these instruments often assumed that all scientists had the same view
and behaved in the same way. Views of NOS in these
instruments were oversimplified and over generalized.
Furthermore, traditional instruments were developed based on an assumption
that students perceive and interpret the statements in the same way as
researchers do. However, research has indicated that
students and researchers used language differently and this mismatch has
almost certainly led to misinterpretation of students' views of NOS in the
past (Lederman & O'Malley,
1990).
Aikenhead,
Fleming, and Ryan (1987)
also found that students may agree upon a statement for very different
reasons. Therefore, traditional instruments often failed to detect the
respondents' perceptions and interpretations of the test items.
It was suggested that empirically derived, multiple-choice responses
could reduce the ambiguity to a level between
15%
and
20%
(Aikenhead,
1988).
Accordingly, Aikenhead and Ryan (1992)
developed an instrument entitled the Views on Science-Technology-Society (VOSTS)
over a six-year period. They analyzed
50
to
70
paragraphs written by Canadian students (grades
11-12)
in response to two statements representing both sides of an NOS issue, to
ensure that all VOSTS items represent common viewpoints possessed by students.
Furthermore, "VOSTS items focus on the reasons that students give to
justify an opinion" (p.480).
The reasons underlying the students' choices of items are particularly
meaningful for teachers to make informed decisions in teaching and for
researchers to interpret students' beliefs appropriately.
Nevertheless, several problems were found with the use of VOSTS.
For instance, some VOSTS items
appeared redundant, and/or
had ambiguous positions and overlapping meanings (Chen,
2006).
Researchers also pointed out that respondents might have combinations of views
that would not be reflected in the multiple-choice format (Lederman,
Abd-El-Khalick, Bell, & Schwartz,
2002;
Abd-El-Khalick & BouJaoude,
1997;
Chen,
2006).
This particular problem may be resolved by using the
Likert scale and scoring model proposed for the
use of VOSTS by Vazquez-Alonso and Manassero-Mas (1999).
Their proposed scale and scoring scheme allow researchers to draw
maximum information of the VOSTS items because respondents circle their views
on all items, and create data that can be applied to inferential statistics.
Most recently, two multi-dimensional NOS assessment tools were developed by
Tsai and Liu (2005),
and Chen (2006),
respectively. Tsai and Liu's instrument, using a
5-point
Likert scale, was designed for assessing high
school students' epistemological views of science (SEVs).
The development of SEVs was based on both the
existing literature and interview data collected by the researchers. The
SEVs instrument consists of five subscales:
the role of social negotiation in science, the invented and creative
reality of science, the theory-laden exploration of science, the cultural
impact on science, and the changing features of science. Chen (2006)
also reported the development of a NOS assessment tool, the Views on Science
and Education Questionnaire (VOSE), built on selected VOSTS items by
incorporating a
5-point
Likert scale. Chen modified
and clarified certain ambiguous VOSTS statements based on the interviews of
both American and Taiwanese preservice secondary
science teachers. The latest version of VOSE was administered to
302
college students majoring either in natural science or language arts at two
research universities in
Taiwan.
Both instruments demonstrated satisfactory validity and reliability
when tested with samples in
Taiwan.
Currently, the most influential NOS assessment tools on views of NOS perhaps
are the Views of Nature of Science questionnaires (VNOS), developed by
Lederman, Abd-El-Khalick,
Bell, and Schwartz (2002).
There are several forms of VNOS (e.g., Form A, B, C, D). With certain
variations in length and complexity of language used in the questionnaires,
all VNOS instruments consist of open- ended questions accompanied by follow-up
interviews. For instance, the VNOS C is composed of
10
free-response questions and takes
45-60
minutes for undergraduate and graduate college students to complete the
survey. This presents a challenging task to respondents with limited knowledge
of NOS and writing skills. Most often, students who
are not equipped to fully express their own ideas in an open-ended format tend
to respond in a few words or simply leave several items blank. This
limits the potential of using VNOS instruments alone as either formative
classroom assessment forms or accurate research tools. Other
supplementary research methods such as follow-up interviews are necessary to
clarify the participants' beliefs.
In summary, significant efforts have been made to modify and/or develop
instruments aimed at increasing validity and minimizing the chance of
mis-interpretation of respondents' perceptions
over the past four decades. It appeared that the open-ended questionnaires
accompanied interviews would yield valid and meaningful assessment outcomes.
However, it may not appropriate as a standardized tool in large-scale
assessments. On the other hand, previous research
suggested that empirically derived assessment tools would significantly reduce
the ambiguity caused by the problem of language. We
therefore have developed the SUSSI instrument, by combining both quantitative
and qualitative approaches to assess students' views about how scientific
knowledge develops.
Copyright (C) 2008 HKIEd APFSLT. Volume 9, Issue 1, Article 1 (Jun., 2008). All Rights Reserved.
