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Asia-Pacific Forum on Science Learning and Teaching, Volume 19, Issue 1, Article 5 (Jun., 2018) |
This research was carried out in the year 2012 with 56 students from the sixth semester of the Bachelor’s Degree in Natural Science and Environmental Education of the Universidad Pedagógica y Tecnológica de Colombia (UPTC, by its acronym in Spanish), which is a public university. In the near future, these students will teach Physics, Chemistry and Biology in the public education system (to 12-18 year olds). The ages of the participants range from 19 to 24 years of age, and 11 are male and 45 are female. In this study, it was considered that the group that is taking said subjects is appropriate for carrying out the intervention, given that they have already seen 60% of the disciplinary and pedagogical contents of the program. Therefore, it can be inferred that they have a good understanding of the scientific contents involved in the activities and have the necessary elements to apply what they have seen in class to different situations of their daily lives. Oral consent was requested from all participants in order to take part in the research and anonymity was guaranteed through the assignment of a numeric denomination.
The research mentioned was carried out over a period of 16 weeks, in three phases: the diagnosis, which involves the pre-test with regard to the privatization of a power station, which was realized in a 90-minute session; the intervention in which 3 sequences of activities about critical thinking and SSIs were carried out, all in 120 minute sessions. In detail, in the first session of the intervention a study related to scientists was done, in which, due to the scientific themes and the SSIs that were dealt with, problems of a different nature arose: ideological, political and economic. The second session was about coffee consumption and the use of chemical additives in its industrialization. The third was about the use of glyphosate for the eradication of illegal crops. They are all open activities that show the multiple dimensions of science (its relations with technology and society, STS) contextualized in Colombia (except for the activity of the scientists, which shows the universal nature of SSIs). In them, the validity of the arguments is questioned, and conclusions rejected which are not based on proof, argumentative fallacies are detected and the credibility of the sources is assessed. Ethical assessments and judgments are made. Supported decisions are reached and actions are proposed. Finally, there is a phase of final assessment referred to the application of the post-test. It is the same as the pre-test, but about different topics from the ones dealt with in class (scientists, glyphosate, coffee additives), so as to confirm that the improvement in the students is the result of them acquiring the competences of critical thinking, and not to the fact that they know more about power stations and their privatization. In addition, this questionnaire was answered 4 months after the pre-test, which guarantees that the improvement is not a consequence of what they remember.
A test was designed that allows for the characterization of critical competences in the SSI environment. The test was used at the beginning and at the end of the intervention, and it deals with the privatization of the electrical power company of the region of the university, so it is a discussed in-context situation. The instrument was applied over 90 minutes, individually, and it was composed of three aspects with 11 questions, grouped in 3 sections and with a length of 2 pages. Said questions can be seen in Table 1, grouped by critical competences.
Section "i" is related to the generation of electricity, and its aim is to question how electrical energy is generated. A scheme is presented that shows the generation of power. From the figure, students are requested to describe the process by which this energy is generated.
Between the items of section "ii", titled Electricity in Colombia, the current state of electricity in Colombia is presented in relation to the energy produced from water, thermal and wind sources. The main objective of this section is that the students question the information presented about the effects of hydroelectric plants on the environment and society. In the last section, the privatization of electricity companies in Colombia, the instrument presents the current state of a social phenomenon in the country related to the privatization of public companies. Fragments published in some newspapers were presented, with statements from different actors, which include political, social and economic aspects.
To assess the internal coherence of the items of the instrument, the Cronbach alpha was calculated with the data collected from a pilot group of 26 students. The value of the Cronbach alpha is 0.8 and, therefore, higher than the value 0.7, which indicates the internal consistency of the questionnaire used. In the same way, the median variance extracted was superior to 0.57, which indicates that the construct shares more than half of its variance with its indicators.
For the analysis of the data collected from this instrument, there were two levels of interpretation. On the one hand, the percentage of students that responded to the questions was calculated. The result accounts for the critical competences established in the framework of the research (Table I). There was also a textual description of the answers given by the participants.
In this article, the comparison between the pre-test and post-test results were presented, in order to describe the influence of the intervention, that is to say, the incidence of SSIs in the development of the competences of critical thinking.
Table I. Competences of critical thinking and questions from the test
CRITICAL COMPETENCES QUESTIONS FROM THE PRE-TEST I. To understand the nature of science as a human activity with multiple relations with technology, society, and the environment. iii.1. Do you identify problems in what was previously described? If your answer is yes, which ones? Why? iii.2. Do you consider that the situation previously described may be the object of reflection of the sciences?
Yes____ No ____
If your answer is yes, in what aspects and why?II. To be informed about the topic, not to be limited to the dominant discourses; to be aware of alternative positions; to question the validity of the arguments, rejecting conclusions that are not based on proof; to detect argumentative fallacies; to evaluate the reliability of the sources, taking into account the underlying interests, and to create well-supported arguments. ii.2. Do you agree with the following: It is affirmed that hydroelectric plants do not cause pollution; they help to stop the emission of CO2 and do not have an impact on the environment. What has been the impact of hydroelectric plants on the environment and society? And that of thermal plants? iii.4. Do you agree with the method of production of electricity in the department of Boyacá? iii.5. What controversies or scientific disagreements related to the production or use of electricity have taken place? III. To study the socio-scientific issue in a comprehensive way, in its complexity: in a way that scientific, technical, ethical, cultural, philosophical, social, economic, and environmental dimensions are involved. i.1.Observe the scheme that appears on the right and describe the procedure that is required to generate electrical power.
i.2. What other procedures that allow a turbine to rotate in order to produce electricity do you know of?
ii.1. How is electricity produced in Boyacá? Who produces it?IV. To value and make ethical judgements around the SSI, attending to their contribution in to the satisfaction of human needs and solving the problems of the world. iii.3. Do you agree with the privatization of EBSA? Why? iii.6. Suppose that you are invited to a debate where the implementation of electrical power in the country is discussed. If your professional assessment o this matter was required, what would your statement be? V. To build statements and conclusions that are duly supported, which lead to making well-supported decisions, to promote actions for the improvement of quality of life, and to be capable of transforming reality, by solving different situations at a personal, family and work level. iii.7. Based on the previous statement, what decisions would it be necessary to make, at a personal, work, and family level, with respect to the previous situation? The analysis of the information collected in the pre-test and post-test is carried out in the software R version 3.0. In order to determine the incidence of intervention with the use of SSIs in the development of competences of critical thinking, the results of the pre-test and the post-test are analyzed. At the same time, in order to verify the benefit of the intervention with the SSIs and its incidence in the post-test, the information obtained from both instruments is compared.
The analysis and classification of the answers provided by the participants to each one of the questions asked in the instrument was carried out from the comparison of the answers with a guide of responses for the instrument, elaborated by the authors.By competence analysis
For each of the competences, there is a rating scale with the levels High, Medium, Low and Insufficient. For each level, a score is established according to the number of questions it contains, for example, competences II and III have 3 questions each, each one of which is evaluated as Adequate Explanations (3 points), General Explanations (2 points), Explanations Out of Context (1 point) and No Answer (0 points), (Solbes and Traver, 2003). To classify the answers in the rating scale, the researchers analyzed the answers independently and, afterwards, a consensus was established among them. Therefore, as said competences are composed of three questions each, which are rated from 3 to 0, their maximum score is 9 and the minimum is 0. In consequence, four levels can be defined according to the points obtained: High 9 and 8, Medium 7, 6 and 5, Low 4, 3 and 2, and Insufficient 1 and 0. If the competences are formed of 2 questions, as is the case of I and IV, the four levels will be: High 6 and 5, Medium 4 and 3, Low 2 and 1, and Insufficient 0.
In order to determine if there are relevant differences between the results of the pre-test and the post-test with regard to the percentage of students in each level, Test Z is used.
The changes that each of the students have experienced are described through 4x4 tables of contingency and, to analyze the differences, the Stuart and Maxwell chi-squared test is used,as there are ordinal variables of more than two categories (Cohen, Manion and Morrison, 2007).
