Is consensus generalizable? A study of Chinese science teacher educators’ views of nature of science content to be taught

In addition to the difference in the scope of the meaning associated with the phrase NOS, there are also many disputes among the contents that are to be included in these definitions. Early in 1960s, it is claimed by Herron (1969) that no sound and precise description existing concerning the nature and structure of science. This claim is echoed later by Meichtry (1993) who notes that the “lack of agreement which has occurred” (p.432) in defining NOS may be due to disagreement over “what characteristics typify the complex and ever-changing field of science” (p.432). Given the contested nature of NOS, there are broadly two different opinions found in the literature on the NOS content to be taught: pluralism and essentialism. According to the pluralistic view, the controversies in NOS should not be avoided in NOS teaching. Instead, the different, and sometimes even conflicting views of science should be included in the teaching of NOS so as to give a real picture of science (e.g. Alters, 1997; Jenkin, 1996; Siegel, 1993). However, when facing the same contested NOS, some others hold that despite the debates on the ultimate NOS, there exists a considerable consensus regarding NOS content to be taught to students (Lederman et al., 2002; Osborne, Collins, Ratcliffe, & Duschl, 2003). Hence they do not think it is necessary to include the disputes among NOS views in their NOS teaching. On the contrary, they suggest focusing on NOS instruction on these agreed-on NOS tenets.

The basic assumption of essentialists is that the consensus does exist among people on what ideas about science should be taught. Two studies relevant to this assumption have been conducted, whose findings are summarized in Table 1. The first one (McComas & Olson, 1998) reviewed eight science standards documents in the Western world, including the United States, Australia, Canada, England and New Zealand. In this study, the authors developed thirty statements about the nature of science from the documents and further identified 13 statements that were found in six or more national curriculum documents (i.e. more than 75%). The participants of another study (Osborne et al., 2003) were 23 Western leading scientists, historians, philosophers and sociologists of science, science teacher educators, experts engaged in the public understanding of science or science communication, and expert science teacher. The research method adopted was three-stage Delphi questionnaire. In the first stage, the participants were asked what they thought should be taught about the methods of science, the nature of scientific knowledge, and the institutions and social practices of science. After then, the authors summarized 30 themes, whose importance were rated on a 5-point Likert scale in the second stage. In the last stage, the 18 themes with a mean rating of >3.6 in the second stage were rated by the participants on its importance. 9 themes were generated, which more than 66% subjects rated as 4 or more and the shift whose rating were one-third or less between Round 2 and Round 3.

Table 1. Comparison of agreed NOS elements indicated in two previous studies

McComas & Olson (1998) (N=8)	Osborne et al. (2003) (Max=5)
*Scientific knowledge*
Scientific knowledge is tentative (8)	Science and Certainty (4.0)
Change in science occur gradually (7)	Historical development of scientific knowledge (4.2)
*Scientific investigation*
Science is an attempt to explain phenomena (7) Scientist are creative (6) Science relies on empirical evidence (6) Scientists require replicability and truthful reporting (7) New knowledge must be reported clearly and openly (6)	Analysis and interpretation of data (4.2) Creativity (4.4) Scientific method and critical testing (4.4) Science and questioning (4.2) Hypothesis and predication (4.2) Diversity of scientific thinking (4.2)
*Scientific enterprise*
Science is part of social tradition (8) Science has played an important role in technology (6) Scientific ideas have been affected by their social and historical milieu (6) All culture contributes to science (6) Scientists make ethical decision (8) Science have global implication (7)	Cooperation and collaboration in science (4.2)

As indicated in Table 1, some agreed NOS elements in these two studies are rather similar, such as “science knowledge is tentative” and “science and certainty”, “science is an attempt to explain phenomena” and “analysis and interpretation of data”, as well as “scientists are creative” and “creativity”. Besides, the lists in two studies both include a good number of NOS elements that are relevant to scientific investigation. A prominent difference between the findings in these two studies is that the former covers a rich list of features of science in the social dimension while the latter has only one.