Use of socio-scientific issues in order to improve critical thinking competences http://www.ied.edu.hk/apfslt/v17

The data obtained in the two tests is surprising in various aspects. One is related to the significant increase by 73.2% in the High level, of competence V: Conclusions and decision-making with p < 0.00. This means that more coherent arguments with personal or familiar decisions are collected, apart from linking their profession as future science teachers to positions regarding the SSI. This coincides with what was found by Day and Bryce (2006), the SSI may have a significant role in scientific and citizen training. Therefore, it is evidenced that SSIs contribute to constructing new statements and conclusions, adequately supported, which lead to making well-supported decisions.

Another aspect is related to the highest degree of difficulty that competence III continues to have for the students. To study the socio-scientific issue in a comprehensive way, in its complexity, in a way that scientific, technical, ethical, cultural, social, economic and environmental dimensions are involved. It is important to highlight an increase from 5.4% in the highest level to 50%. This may be due to the fact that it requires a greater level of comprehension in multiple topics and establishing relations among them.

The above reflects that the students relate, to some extent, the concepts of chemistry with the description of energy generation. However, many only transcribe the image presented in the test without any interpretation whatsoever. The data indicates that in the post-test the participants are more informed about the production of energy in their region. They also include the importance of the generation of alternative and renewable sources in coherence with other studies (Driver, Newton and Osborne, 2000; Sadler, 2004; Windschitl, Thompson and Braaten, 2008), which indicates how the use of SSIs in a science class offers opportunities for the development of a citizenry capable of applying scientific concepts and promoting ethical consciousness. Other aspects that stand out in the post-test are related to better-supported answers with regard to the production of electricity in the country.

The statistical analysis carried out with the chi-squared test of marginal homogeneity of Stuart and Maxwell indicates a favourable effect in all the competences with values p < 0.05 and reflects a reduction in the number of students who do not respond to questions in the post-test. Nevertheless, the data indicates a greater improvement in competence II: To learn to question information; competence V: Conclusions and decision-making, and competence IV: Assessment and Making of ethical judgment, considering that these registered a greater number of students in the Low and Insufficient levels in the pre-test.

The above shows that the use of SSIs in the classroom facilitates the development of critical competences. Therefore, promoting pedagogical and didactic processes from within the classroom from the SSI approach can strengthen the processes of the development of critical thinking. Thus, the results presented show an inclusion of the social aspect in the study of the scientific concepts in consistency with Albe (2008); Rundgren, and Yao (2014), according to whom the teaching of science must have a meaning in social interactive processes where the human being learns and interacts with the reality of others. This suggests that the influence of the context constitutes a possibility to reflect upon social, economic and political topics.

In the same way, it also allows for the promotion of communication processes in the classroom, and as Van Zee and Minstrel (1997); Seyhan (2015) point out, spaces for the students to express their thoughts, comments and questions must be fostered. This gives the students the responsibility of thinking and contributing in order to articulate ideas, beliefs and concepts. In the same way, the data obtained agrees with the studies of Albe (2008), and Dawson and Venville (2010), which indicate how the construction of arguments in a collaborative way may facilitate better-supported arguments and opinions. In this study, the activities about the consumption of coffee and the use of glyphosate were dealt with in groups.

Finally, the data shows that the SSIs allow for approaching real problems from social, environmental, and scientific aspects that promote the formation of well-supported opinions. These situations, different from what is regularly used in science classes, allow for the localization of the issue in an environment or context that makes the learning of scientific concepts more meaningful. This is important as a contribution to the autonomy that teachers may have when designing the curricula. It also favours the possibility of creating collective spaces of study and curricular planning which go beyond the accumulative, homogeneous, linear and the technical rationality approaches.