 |
Asia-Pacific Forum on Science Learning and Teaching, Volume 19, Issue 1, Article 5 (Jun., 2018) |
The results presented below are the product of a didactic intervention that consisted of the use of diverse SSIs, as was mentioned earlier. Therefore, in this article the pre-test and post-test results are presented, referring to the SSI on the privatization of a power plant, which allows us to indicate the influence of the SSI in the competences of critical thinking as shown in Table I.
The data presented in the following tables shows the percentages of students in each one of the levels and the p values found with the statistical Z. It is observed that the best values are registered in the High level, in competences II, IV and V with a p that equals 0.00. The post-test evidences an increase in the number of students reaching better levels, with a different level of difficulty to that of the pre-test. In the pre-test, values for competences in the following order were obtained III<II<V<IV<I. In the post-test, the values are ordered as follows: III<V<IV<II<I. It is observed that, in both tests, competence I is in first place and competence III is last.
Below, the results for each one of the competences are presented:
Table II. Comparison between the pre-test and post-test in competence I
Levels Pre-test 48.2 39.2 8.9 3.6 Post-test 91.0 7.1 1.8 0.0 p value 1.8·e-8* 6.8·e-6* 0.0* 0.0* Asterisks represent significant differencesCompetence I: To acknowledge the nature of science as a social activity obtains the best percentage in the post-test. It increased by 42.8% in the High level, with a p = 0.00 (lower than the level of statistical significance 0.05). This value shows that the students identify the problem of privatization and relate it with the study of science, as can be seen in the following answer, written by students E22 and E9 in the post-test when they are asked the question: Do you consider that the situation described as the privatization of energy in Boyacá can be an object of reflection of the sciences?
- Answer written by student E22 in the post-test: “Yes, because the reflections made in relation to science involve social, environmental, economic, political and technological aspects, and the above situation shows us how science has facilitated our activities but, at the same time, it creates a certain dependence on them, which has increased consumption policies, therefore, it has to be reflected on what science is producing in order to contribute to the environment.”
- Answer written by student E22 in the pre-test: No answer.
- Answer written by student E9 in the post-test: “The privatization of the electricity company is a problem that involves various aspects, social and economic, for example the cost of electricity in Boyacá, the people who have worked for the company for years might be fired, and in the field of the science, which involves the social aspect, the following could be studied: the efficiency of the equipment used, the use of generators, and the invention of new technologies which are more eco-friendly and that are sustainable.”
- Answer written by student E9 in the pre-test: “It is only a political problem. It is not related to science, as it does not study any phenomenon.”
In their affirmations, the students improve their understanding of the nature of science after the SSI and start to acknowledge the social role of science.
Table III. Comparison between the pre-test and post-test in competence II
Levels Pre-test 7.1 42.8 42.8 7.1 Post-test 89.2 8.9 1.8 0.0 p value 0.0* 4.49·e-6* 1.11·e-9* 0.02* Competence II: To learn to question information increased significantly from 7.1% to 89.2%. This indicates that the students became informed with regard to alternative positions and rejected the statements that were not completely valid. This is translated into a greater degree of information when questioning and not giving full credibility to some statements. For example, one of the questions for this competence presents the following statement: 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. It is sought that the participants detect the fallacy and question the information presented. With respect to this, 30% of the students did not detect the fallacy in the pre-test and gave answers such as the following:
E1: “Yes, I agree with the above. I do not know of any environmental impact of great magnitude with reference to hydroelectric plants.”
E24: “I agree with the fact that hydroelectric plants mitigate environmental pollution as they barely emit gases.”
In the post-test, the students responded:E1: “They produce an environmental, economic and social impact.”
E24: “…although they are sources of renewable energy, they alter the reproductive cycle of aquatic fauna because of the construction of artificial ponds and alter the amount of water in rivers, their temperature and degree of oxygenation”.
In the interventions of the post-test, the students indicate the environmental impact of hydroelectric plants on an aquatic and terrestrial level. As regards thermal plants, they mention the increase in polluting gaseous emissions. Their final affirmations account for the inclusion of the environmental dimension, which was comparatively limited in the answers of the pre-test.
Table IV. Comparison between the pre-test and post-test in competence III
Pre-test 5.4 38.0 42.8 14.2 Post-test 50.0 41.0 8.9 - p value 6.0·e-10* 0.37 4.49·e-6* 0.001* Competence III, referring to the multidimensionality of science, went from 5.4 to 50% in the higher level, which indicates that the students analyze SSIs from different dimensions: scientific, ethical, cultural, social, economic and environmental. This percentage also shows that in the post-test students are more informed about the production of energy in the department of Boyacá and include the importance of the generation of energy through alternative sources. In the following affirmation, made by student E53, their opinion on privatization is expressed, once the intervention had been realized:
E53: “I do not agree; first because it is a company that belongs to us and, second, because all companies may have economic or productivity problems at some point, what is obvious is that they want to sell it to a single organization and they are not taking into account what the people who have worked at the company say.”
Table V. Comparison between the pre-test and post-test in competence IV
Pre-test 27.0 51.7 14.2 7.1 Post-test 89.2 10.7 7.1 - p value 0.0* 9.9·e-8* 0.001* 0.97 In competence IV: Assessment and making of ethical judgments. A 58.7% rise stands out, which accounts for the importance of making ethical judgments regarding SSIs, attending to their contribution and the satisfaction of human needs. In this competence, it is highlighted that the students make statements related to the implementation of electric power in the country and make a professional assessment with respect to the topic. As can be seen in the opinions of E2 and E19 as an answer to the question: Do you agree with the privatization of EBSA? Why?
E2 in the post-test: “In my opinion, the country should implement better practices to obtain electricity. Colombia has a large variety of terrains that are suitable for the implementation of alternative energies, apart from hydroelectric and thermoelectric, such as wind and solar, what is important is to think about the future of the new generations.”
E19 in the post-test: “Electric power companies should not only think about the economic aspect, but also come up with strategies for the use of resources, seeking the least possible harm, so as to maintain balance in the environment.”
They also take their own stance as future teachers of the natural sciences who promote citizen formation and the development of values for the democratic participation in topics of science and technology, as students E43 and E53 point out in their interventions.
E43. “It is necessary to seek for renewable sources of energy, such as solar or wind, and in the departments that are closer to the sea, tidal energy can be used. In that way, pollutants would be partially stopped. For example, projects with students can be implemented where the advantages and disadvantages of diverse types of processes of electricity generation can be studied, and at the same time teach concepts such as energy, types of energy, etc.”
E53: “At present, the country has many companies, but as a future teacher of the natural sciences I think that the impact that they have on the environment should be looked at, these can be mitigated through cooling towers and other alternatives.”
Table VI. Comparison between the pre-test and post-test in competence V
Pre-test 12.5 28.5 12.5 46.4 Post-test 85.7 7.1 1 - p value 0.0* 0.001* 0.16 2.6·e-12* In competence V: Conclusions and decision-making there are very significant values in the high and medium levels. This indicates that the students make statements regarding decisions at a personal, work and family level. Also, it is evidenced that the percentage of students in the low and insufficient levels drops. By way of example, the intervention of student E14 is presented:
Intervention by student E14 in the post-test: “More than decisions, we need to train ourselves in ethical values because if we know that these methods are not the most adequate, we need to look for others that do not harm the environment so seriously and, on the other hand, we must give our opinion about energy with the aim of preventing the problems that are taking place. For my part, it is important to have more knowledge on the topic so as to be able to reflect upon energy saving in educational institutions.”
Intervention by student E14 in the pre-test: “We have to be ready because prices will rise due to privatization.”
The previous affirmations prioritize the need to promote spaces for reflection regarding the topic of energy saving. This contributes to making possible spaces of critical consciousness and social responsibility, in this case from their position as teachers of the natural sciences.
Implications of SSIs in the pre-test and post-test
In order to show the changes brought about by the intervention in each competence, not only at a percentile level, but also analyzing the changes that each of the students have experienced, we will use tables of contingency. Below, the analysis of the implications of SSIs in the pre-test and post-test is presented.
For the pertinent analysis, 4x4 squared tables are used, the data of which comes from paired samples, given that, in the research the same students took part in the pre-test as well as in the post-test. At the same time, the categories used in rows and columns correspond to high, medium, low and insufficient levels.
Table VII. Comparison between the pre-test and post-test in competence I through contingency tables
COMPETENCE I (PRE)
POST
High 23
21
5
2
51
Medium 3
1
0
0
4
Low 1
0
0
0
1
Insufficient 0
0
0
0
0
Total 27
22
5
2
56
The table indicates the change the students have gone through. In the diagonal, there appear those who have not changed, on the top right corner, those who have improved and in the bottom left corner, those who have worsened. In the pre-test, 21 were in the Medium level, 5 in Low and 2 in Insufficient, and they rose to the High level in the post-test. It is observed that 3 students dropped, in the pre-test they were in the High level and, in the post-test, they went down to Medium level. At the same time, it is observed that 1 student worsened, going from High to Low level. There are 24 students who remain the same, 23 that had a High level in the pre-test and 1 that was registered in the Medium level.
In this sense, the data delivered by the R program allows us to obtain the value of the statistical c2 = 18.16 and a value p<0.00which indicate the contribution of the SSI to the understanding of science as a social activity.
Table VIII. Comparison between the pre-test and post-test in competence II through contingency tables
COMPETENCE II (PRE)
POST
High
Medium
Low
Insufficient
Total
High 4 22 20 4 50 Medium 0 2 3 0 5 Low 0 0 1 0 1 Insufficient 0 0 0 0 0 Total 4 24 24 4 56 In competence II, the positive effect of the intervention is observed in 46 students. This allows us to infer that the students question the information presented to them, which means to assess the impacts of the thermal and hydroelectric plants as producers of energy. Among the most common answers, the ones that stand out are those referring to environmental impact, followed by climate change, greenhouse effect, the effect of the plants on the biodiversity of marine ecosystems and the displacement of people from their places of origin.
In competence III, the rise of 27 students to the High category is observed. In the post-test, no students are reported in the Insufficient level. Out of the 8 registered in this level in the pre-test, 3 scaled to the High level and 5 to the Medium level. It can be seen that 8 students of the Medium level, 4 of Low and 1 from High, remained the same. Therefore, in this competence, 23% of the students were not affected by the didactic intervention. In contrast, 2 students who were in the High level worsened in the post-test.
Table IX. Comparison between the pre-test and post-test in competence III through contingency tables
COMPETENCE III (PRE)
POST
High 1 13 11 3 28 Medium 1 8 9 5 23 Low 1 0 4 0 5 Insufficient 0 0 0 0 0 Total 3 21 24 8 56 The statistical test allows us to obtain a value of c2 = 31.09 and a value p < 0.00 which is significant so as to assess how the participants include various dimensions, such as the scientific, ethical, cultural, social, economic and environmental in the analysis of the SSI referring to the privatization of electricity. Likewise, they relate aspects such as the production of combustion reactions of coal, oil or gas that heat a liquid with a lot of pressure and Faraday’s Law, etc.
In competence IV, the chi-squared test of marginal homogeneity shows a statistical value of the contrast of symmetry of c2 = 33.68 and the value p < 0.00. For this matter, the result indicates that the SSIs allow for the linking of essential instruments for citizen participation, such as the production of clean energies, the implementation of energy saving strategies, the use of energy for social wellbeing and the generation of actions at a curricular level for the adequate use of energy.
Table X. Comparison between the pre-test and post-test in competence IV through contingency tables
COMPETENCE IV (PRE) POST
High 13 29 5 3 50 Medium 2 0 3 1 6 Low 0 0 0 0 0 Insufficient 0 0 0 0 0 Total 15 29 8 4 56 In this competence, there are positive changes in the post-test. The data indicates that 37 students have gone up to High level whereas 3 students, who were in the Low level, went up to Medium. Those students who were in the Insufficient level have improved and ascended to the scales High and Medium. In the post-test, there are no students in the lowest categories.
Finally, in competence V, the statistical test calculated in R allows us to obtain the statistical value c2 = 40.41 and a value p < 0.00. The answers of the post-test deal with general aspects that highlight the participation and information regarding problems affecting the public sector, the impact of companies. In addition, the participants show ideas of their own, from their training as science teachers, where they highlight the importance of promoting critical positions and prioritize the need to originate spaces for reflection with regard to the topic of energy saving.
Table XI. Comparison between the pre-test and post-test in competence V through contingency tables
COMPETENCE V (PRE)
POST
High 6
13
6
23
48
Medium 1
2
1
0
4
Low 0
0
0
0
0
Insufficient 0
1
0
3
4
Total 7
16
7
26
56
