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Asia-Pacific Forum on Science Learning and Teaching, Volume 17, Issue 2, Article 5 (Dec., 2016) |
Study Design
This study used the nonequivalent control group design (Gay, Mills, & Airasian, 2012). The experimental and the control groups were administered in this study as a pre-test; the experimental and the control groups were administered as a pre-test; the experimental group had POGIL instruction, while the control group had traditional instruction and then the post-test was administered to both the experimental and the control groups. Two experimental groups and two control groups were randomly selected from four available groups (classes). Experimental groups were instructed using the POGIL method, while control groups were given traditional chemistry instruction. All groups received identical syllabus-prescribed learning content. The study was conducted over a six week semester.
Sample of Study
This study comprised 115 11th-grade students (61 boys and 54 girls) from four intact classes with two teachers. The study was conducted in a large urban district. Two of the classes were set as the experimental group (n= 56), and the remaining two classes were randomly set as the control group (n= 59). Two experimental and two control groups were selected because the researchers wanted the study to be conducted with a larger sample. Furthermore, assumptions of statistical analysis are better provided in large samples. The ages of the students ranged from 15 to 16 years old. The socioeconomic status (SES) of the students in the experimental and control groups was similar, with the majority of the students coming from mid-SES to upper-SES families. Two chemistry teachers were included in the research. Each teacher had one experimental group and one control group. This prevented the treatment diffusion factor, which is one of the factors affecting the validity of the study. Prior to the teaching the lessons in experimental groups, the researcher and the teachers exchanged information about POGIL and that day’s activity.
Instrument
The Electrochemistry Concept Test (ECT) was developed by authors. The purpose of ECT is to determine students’ conceptual understanding of electrochemistry, and to reveal alternative conceptions about the subject. The ECT included 19 questions. The questions in ECT are not similar in POGIL exercises. The ECT comprised three tier multiple choice questions and the POGIL exercise included open-ended questions and problems. All of the questions were prepared using the course books that the schools had given to the students. The questions in the control group exercises were prepared by their teacher based on the traditional teaching method and these questions were similar to the questions in the POGIL exercises. The questions prepared were related to reduction, oxidation, electrodes, electrochemical cells, galvanic cells, concentration cells, electrolysis, and Faraday’s laws. Each was a three-tier question. The first tier of each question was a multiple-choice question, and had five alternatives. The second tier again had five alternatives, but here students were asked to state the reason for their choice in the first stage. The distractors in the second tier were generally the alternative conceptions concerning electrochemistry. In the third tier, students were asked to state how confident they were in terms of their answers to the questions in the first and second tiers. To calculate total scores, the answers of students of each question in the first, second and third tier (confidence level) were evaluated. If the answer of the students in the third tier was ‘I am sure’ for their incorrect responses in first and/or second tier, this indicated that these students have alternative conceptions; however, if the answer of the students in the third tier was ‘I am not sure’ for their incorrect responses in first and/or second tier, this indicated that these students lacked knowledge.
Two experts in chemistry education reviewed each item and the content validity of the ECT. The items were revised based on suggestions submitted by the experts. Prior to the administration the ECT as a pre-test, a pilot study with 268 students (excluding the students in the experimental and control group) was conducted to assess the face and content validity of the test. The students in the pilot study were 11th-grade students from similar mid-SES to upper-SES families. The items were revised and some rearranged, according to the results of the pilot study. In the ECT evaluation, students who had answered the first and second stages of the test correctly and who had been sure of their answers received 1 point; and those who had answered one or both stages of the test incorrectly received 0 point (Arslan, Çiğdemoğlu, & Moseley, 2012; Gürcay & Gülbaş, 2015; Pesman & Eryılmaz, 2010). Following reliability analyses, the Cronbach Alpha value was found to be 0.810 for the 19-item test.
Procedures
The experimental and control groups both received 36 hours of teaching. Each group instruction comprised four 45-minute sessions per week and each POGIL activity was one 45-minute session, only for critical thinking questions (except for exercises and problems in POGIL activities). Two high school teachers participated in the research. Both teachers used the POGIL method in their experimental group and the traditional teaching method in their control group. The researchers qualified in science and chemistry education prepared the POGIL activities. Experts in science education and chemistry teachers checked the POGIL activities, conducted various scientific studies in teaching and learning approaches. During the two weeks prior to the treatment, the teachers were informed about POGIL activities and their use, over a period totalling eight hours. Teachers prepared POGIL activities relating to different chemistry topics. Following this, the researchers provided samples of different POGIL activities in the literature. In this process, the researchers provided more information and details about POGIL and the application of POGIL in the classroom.
Treatment in the Experimental Group
The experimental group of students were taught using the POGIL method. POGIL is a learner-centered approach that focuses on small groups of students (4-5) engaging in inquiry-based learning activities. The students in the experimental group worked with POGIL activities designed on the basis of the three-phase structure of the Learning Cycle; namely, the exploration phase; the concept invention phase and application phase.
Prior to the application, sessions were held with the chemistry teachers in the schools included in the study and the teachers were informed about the POGIL method. Subsequently, taking the teachers’ opinions into account, the final shape was given to electrochemistry course, materials were prepared using POGIL and these materials were given to the teachers for them to use in their teaching. First of all, the teachers informed the students in the experimental group about the POGIL method, the concept maps and the preparation of the lotus blossom technique. The lotus blossom technique is a data collection tool to determine students’ ideas, cognitive structures, and understanding in relation to a concept (Palıcıca, Gavrılă, & Boacă, 2010; Yaqoob, 2007). Groups were formed from each experimental group in accordance with cooperative learning method procedures. These groups, who would study in the classroom setting, were formed heterogeneously, according to achievement levels (high achievers, middle achievers, and low achievers), based on the results of the previous chemistry exam and then the application began.
The students in the experimental group, who would be taught using the POGIL method, were told about their roles in their groups (managers, presenters, recorder, and reflectors etc.). It was explained to them that they would take turns in playing these roles for each activity. As well as their tasks, the rules they would follow were also explained to them. They were told that while responding to critical thinking questions in particular the group should have shared views. Furthermore, in order to be able to follow the process effectively, each group was asked to prepare a group file containing their work and the answers they gave to the questions.
In order to contribute to the evaluation of the POGIL method, quizzes would be given to students at the beginning of each lesson. In this study, concept maps and the lotus blossom technique were also used, so that the students could assess their learning process and see their mistakes and their progress. At the end of each lesson the students were given five minutes to prepare the concept maps and lotus blossoms, after which they were collected. The students were given no extra time.
The students studied cooperatively in the groups during the prepared activities, on the basis of the three-phase structure (exploration phase, concept invention phase and application phase) of the learning cycle. Meanwhile, the teacher walked around the classroom and checked the group’s shared answers as shown in the notes taken by the recorders. When necessary, the teacher intervened and guided the students in their learning process. The students were asked to respond only to the critical thinking questions included in the activities.
The teacher also encouraged interaction between the groups. From time to time, the teacher asked a group to explain their answers to the critical thinking questions to the whole class. In this way, the groups had the opportunity to compare their answers and thus dispense with their contradictions. Certain groups sometimes took on the role of consultant for other groups and helped them to understand the activities.
POGIL Activities Used in the Study
The opinions of a board of experts comprising chemistry educators and chemistry teachers were obtained for the preparation of the POGIL activities used in this study. The necessary arrangements for the activities were made in accordance with their opinions. A total of nine POGIL activities were prepared for the study, in relation to subjects including reduction, oxidation, electrodes, electrochemical cells, galvanic cells, concentration cells, electrolysis, and Faraday’s laws. All the activities were designed by the researchers. A varied number of models and critical thinking questions were developed for each activity. In addition to this, exercises and problems were prepared at the end of each activity. A sample activity is shown in Appendix A.
Treatment in the Control Group
The control group students were taught using traditional chemistry teaching methods (teacher-centered approach). Although the Turkish chemistry curriculum suggests constructivist learning environments to enhance learning and support conceptual change, Turkish chemistry teachers do not hold positive beliefs about implementing constructivist teaching methods in schools, such as problem-based learning, project-based learning and inquiry based learning. Therefore, many chemistry teachers in Turkey use traditional chemistry instruction. Traditional instruction is a teacher-directed strategy, based on teacher’s explanations, discussions, and textbooks. Management and responsibility for learning are teacher-centered. This traditional teaching views students as the passive recipients of information. In the control group, lessons were taught in the traditional chemistry teaching method in the form of lectures and questioning. A teacher-centered teaching approach was adopted in the process of learning the concepts related to reduction, oxidation, electrodes, electrochemical cells, galvanic cells, concentration cells, electrolysis, and Faraday’s Laws. Before attending class, the students studied the subjects in their course books. The classroom environment and the whole learning process was structured by the teachers. The teachers required the students to take notes, they explained the concepts using the blackboard, drew figures related to electrochemistry, prepared charts about galvanic cells and concentration cells, and solved sample problems. The teachers asked the students questions and required them to participate in discussions that were always under the teachers’ control. The coursework material were the examples, figures and pictures contained in the worksheets and course books.
Also, in the control group, concept maps and mini quizzes were used as an assessment tool to examine the students' understanding of electrochemistry concepts. Apart from the POGIL activities, all the activities in the experimental and control groups were similar. Instead of POGIL activities being used, the teachers made activities/materials based on traditional teaching methods.
