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Asia-Pacific Forum
on Science Learning and Teaching, Volume 14, Issue 1, Article 6 (Jun., 2013) |
This study employs a quasi-experimental design, in which two secondary 4 (grade 10) classes of a Hong Kong secondary school were taught about the same topic, human reproduction, with one class employing the STSE approach and the other class taught traditionally. The scientific literacy of the students of the two classes were assessed and compared.
The school was a band one school (intake of top 30% of primary students) and used English as the medium of instruction. All the students were Chinese with ages ranging from 14 to 16. They were allocated evenly into the two S4 classes according to their overall academic results in S3, so the average academic abilities of the two classes were similar. Both classes were taught by one teacher in order to reduce the variability stemming from the basic qualities of the teacher, though the teacher variable is still a significant and unavoidable factor when he attempted to teach in two different approaches.
Assessment of scientific literacy
Based mainly on the framework of PISA, scientific literacy was assessed in this study on six domains: 1. Recall of concepts; 2. Application of concepts in unfamiliar situations; 3. Scientific inquiry skills; 4. STSE awareness; 5.Understanding of the nature of science; 6. Attitudes towards science learning. Tests were constructed for the assessment of these domains, which were first validated by two science educators and then trailed in a group of about 10 students to improve their clarity and validity.
A test consisting of short-answer questions was constructed to assess the recall, understanding and applications of the biological concepts. Similar to PISA, several items were clustered into one unit under the same STSE context, such as the cloning of sheep, amniocentesis and in-vitro fertilization. To make the assessment fair, only the concepts covered by both classes were assessed and the contexts used were novel to both classes. The breadth and depth of the test are set in line with the biology certificate examination of Hong Kong in order to investigate if the STSE approach can cope with the heavy demands of the public examinations. The content and construct validity of the test were judged by two experienced biology teachers. Students of both classes took the test shortly after the course and the performances of the two classes were compared after adjusting for their biology scores in the last year using analysis of covariance (ANCOVA). This can compensate partly for the lack of pretest in the study.
A test for the assessment of scientific inquiry skills was constructed (see Appendix 1.) based on several sources: PISA’s assessment framework and items, Test of Integrated Process Skills (TIPS) (Dillashaw and Okey 1980) and Biological Investigations Test (Germann 1989). The test consists of 22 multiple-choice items, which was validated independently by two experienced biology teachers. The test was administered to the two classes as pretest-posttest and the scores of the two classes were compared using one way analysis of covariance (ANCOVA).
The students’ attitudes toward science, STSE awareness and understanding of nature of science were assessed by a Likert-scale questionnaire in a pretest-posttest manner. The items were adapted from some existing instruments: the Views on Science-Technology-Society (VOSTS) (Aikenhead and Ryan 1989) for the assessment of STSE awareness, the Inventory of Scientific Attitudes (Moore and Sutman 1970) for the assessment of NOS understanding, and the revised Inventory of Scientific Attitudes (Moore and Hill 1997) for the assessment of attitudes toward science and science learning. For each assessed construct, there are both positive and negative statements (Table I) and the scores of the two classes were compared by ANCOVA, with the pretest scores as covariates.
Table I. A sample of the Likert–scale items for the assessment of STSE awareness, understanding of nature of science and attitudes toward science STSE awareness
Only doctors have the right to decide on what treatments to be made on the patients, as they have best medical knowledge. (+)
The patients and their families, rather than the doctors, should have the right to decide what treatments to receive, as the decisions affect themselves. (–)
Understanding of nature of science
Some questions cannot be answered by science.(+)
Anything we need to know can be found out through science.(–)
A useful scientific theory may not be entirely correct, but it is the best idea scientists have been able to think up.(+)
Scientific laws have been proven correct without any possible doubt.(–)
Attitudes
Biology class is interesting. (+)
Biology is the subject I dislike most.(–)
Note: The (+)/(–) denotes the informed/naïve views, or positive/negative attitudes.
STSE course and traditional course
The STSE course was designed by the researcher of this study together with the teacher of the classes. It was trialed in another class and the students were interviewed to collect feedback for the improvement of the course. In the design of the course, the first principle is to take account of the learning of the biological knowledge as required by the exam syllabus, thus leaving only about 30% of the instruction time to the development of the scientific inquiry skills, decision making skills, and understandings of nature of science and STSE connections. This emphasis on content knowledge is thought vital for the STSE course to be accepted by teachers and schools in Hong Kong under intense exam pressure. Another challenge is to identify clearly and minimize the knowledge outside of exam syllabus since students in Hong Kong are very pragmatic and exam oriented. However, this poses difficulty in the design of the course since many STSE themes would require much knowledge outside the exam syllabus.
There are four STSE themes in the course: 1. Intersexuality; 2. Teen sex and pregnancy; 3. Infertility; 4. The journey to become a mother. (See Appendix 2). These themes were carefully chosen for their relevance to the biological knowledge required by the exam syllabus, and their potentials to develop the skills, understandings and values regarding STSE connections, scientific inquiry and nature of science. In addition, these themes were deemed interesting to the students and could enhance their attitudes towards science.
With an emphasis on learning the required disciplinary knowledge, the STSE course developed in such a way belongs to the category of singular discipline through STS content in Aikenhead’s (1994) categories. As for the six currents of STSE education as proposed by Pedretti and Nazir (2011), this STSE course is closer to the current of logical reasoning since it stresses rational decision making for socioscientific issues based on scientific knowledge and skills. Also, it addresses more the Vision I of scientific literacy by Roberts (2007). Despite that, values and morals are also addressed throughout the course, for instance, patient rights, respects for the intersexuals, and values related to abortion and contraception.
The teaching lasted for about two weeks using nine 40 minute lessons. A wide variety of interactive learning strategies were used in the STSE course such as, brainstorming, structured group discussion, open class discussion, jigsaw learning, case studies, debates, role plays, simulation, decision making, problem solving (See Appendix 3) since interactivity is at the core of STSE instruction (Byrne and Johnstone 1988). For the learning of scientific knowledge, however, direct teaching is still the principle method employed. This is to ensure that the efficiency of content learning in terms of instruction time would not be compromised in the STSE course. Nonetheless, the STSE course is estimated to require 50% more instruction time than the traditional course in covering the same amount of content.
The teaching basically follows the sequence shown by Figure 1. Teaching starts from the socioscientific issues, then moves through related technologies and scientific knowledge, and finally returns to the issues for their resolution. The issues are resolved, bit by bit, along with progressive acquisition of relevant knowledge. Teaching shifts regularly between issues resolution and content learning so that students can learn on a need-to-know basis and apply their learning within meaningful contexts. Take for example, in the unit of intersexuality, the students first read the stories of an intersexual, from which the chllenges of determining gender are raised. Then, the reproductive systems and secondary sexual characteristics of man and woman are taught. With the knowledge learned, students revisit the issues to discuss which gender the person in the story should be assigned. The discussions, though largely rational and science-based, also address the rights and feelings of the intersexual.
Figure 1. The instructional sequence of STSE (Aikenhead, 1994)
The traditional class was taught in a more “traditional” way: the biological concepts were presented first, followed by some of their applications in everyday life. It is closer to category 1 of Aikenhead’s (1994) framework- motivation by STS content. The organization of the contents is mainly determined by the internal conceptual structure of the topic as in most traditional textbooks. For example, teaching started with the general anatomical structures of the male and female reproductive system, and then the detailed functions of each part are explained one after one. This organization makes the traditional course, as compared to STSE approach, more systematic in concept learning and students will be given the prerequisite knowledge before learning a new concept. However, the downside of this traditional approach is that the concepts are not learned on a need-to-know basis in meaningful contexts. Moreover, the traditional course does not play particular attention to scientific inquiry, nature of science, STSE interrelationships and sociocultural perspectives. Nonetheless, the instruction of the traditional class is not necessarily didactic. It was interactive using extensive class discussions and multimedia, but, as compared to the STSE course, it was more teacher-centered and did not have much student group discussions and independent work.
