Reexamining the Role of Cognitive Conflict in Science Concept Learning

Abstract In this study, we defined and quantified the degree of cognitive conflict induced by a discrepant event from a cognitive perspective. Based on the scheme developed, we investigated the relationship between cognitive conflict and conceptual change, and the influences of students’ cognitive characteristics on conflict in learning the concept of density. Subjects were 171 seventh-grade girls from two city middle schools in Korea. Tests regarding logical thinking ability, field dependence/independence, and meaningful learning approach were administered. A preconception test and a test of responses to a discrepant event were also administered. Computer-assisted instruction was then provided to students as a conceptual change intervention. A conception test was administered as a posttest. In analyzing students’ responses to the discrepant event, seven types of responses were identified: Rejection, reinterpretation, exclusion, uncertainty, peripheral belief change, belief decrease, and belief change. These types were then ordered into four levels. The results indicated that there existed a significant correlation between cognitive conflict and conceptual change. t -test results revealed that there were statistically significant differences in the degree of cognitive conflict by the levels of students’ logical thinking ability and field dependence/independence. Meaningful learning approach, however, was found to have no statistically significant effect on cognitive conflict. Educational implications are discussed

Perceived professional needs of Korean science teachers majoring in chemical education and their preferences for online and on-site training

In this study, we investigated the perceived professional needs of Korean science teachers majoring in chemical education, and examined their preferences for online and on-site inservice teacher training programs. The results were also compared with those of preservice teachers. Participants were 120 secondary school teachers and 67 preservice teachers, whose majors were either chemical education or science education with emphasis in chemistry. A questionnaire consisting of a modified Science Teacher Inventory of Need and a section concerning respondents’ demographic information and their use of the Internet was administered. In contrast to previous studies, the perceived needs of Korean inservice and preservice teachers were found to be very strong in all 30 needs assessment items, and their prominent needs were from all seven categories. Preservice teachers indicated significantly greater needs than inservice teachers on several items. Korean teachers generally tended to prefer online inservice to traditional on-site training programs, although they still preferred on-site types of programs in areas such as conducting laboratory sessions and demonstrating manipulative skills. Preferences for online programs tended to be stronger among preservice teachers than inservice teachers, and among non-veteran teachers than in veteran teachers. Educational implications are discussed

Cognitive conflict and situational interest as factors influencing conceptual change

In this study, we investigated the relationships among cognitive conflict and situational interest induced by a discrepant event, attention and effort allocated to learning, and conceptual change in learning the concept of density. Subjects were 183 seventh graders from six middle schools in Seoul, Korea. A preconception test, a test of responses to a dis-crepant event, and a questionnaire of situational interest were administered as pretests. Computer-assisted instruction was then provided to the students as a conceptual change in-tervention. Questionnaires regarding attention and effort, and a conception test were admin-istered as posttests. The conception test was administered once more as a retention test four weeks later. The results of path analysis indicated that both cognitive conflict and situational interest induced by a discrepant event respectively had an indirect effect on students‘ conceptual understanding, which were mediated by attention and effort allocated to concept learning. Situational interest, however, was found to exert a stronger influence on conceptual change than cognitive conflict. It was also found that attention, either directly or indirectly through effort, influenced students‘ conceptual understanding

A Study on the Elementary School Teachers’ Awareness of Students’ Alternative Conceptions about Change of States and Dissolution

Knowledge about students’ conceptions is one of the requisite components of pedagogical content knowledge. A keen awareness of students’ alternative conceptions provides teachers with information about prospective difficulties students may incur as they make attempts to learn more accurate scientific representations of critical concepts. In this study, we investigated elementary school teachers’ understanding of their students’ alternative conceptions about change of states and dissolution. The subjects were 152 elementary school teachers and 529 sixth graders in Korea. A conceptions test and the test of the understanding about students’ conceptions were administered in order to examine students’ alternative conceptions and the teachers’ awareness of their students’ alternative conceptions, respectively. The effects of teachers’ characteristics such as teaching experience, highest academic degree, science teaching efficacy, and views about teaching and learning (i.e., constructivist and traditional) in relation to their awareness of students’ alternative conceptions were also investigated. The results indicated that the teachers tended to overestimate the number of students with scientifically accepted conceptions. The teachers also did not possess adequate knowledge about the existence and the distribution of their students’ alternative conceptions. It was found that teaching experience, highest academic degree, science teaching efficacy, and the level of teachers’ adoption of a constructivist view about teaching and learning were not significantly related to the their awareness of students’ alternative conceptions. It was found, however, that there is a significant relationship between the level of teachers’ traditional view about teaching and learning and their awareness of students’ alternative conceptions. Educational implications are discussed

Examining Students’ Views on the Nature of Science: Results from Korean 6th, 8th, and 10th Graders

In this study, students’ views on the nature of science (NOS) were investigated with the use of a large-scale survey. An empirically derived multiple-choice format questionnaire was administered to 1,702 Korean 6th, 8th, and 10th graders. The questionnaire consisted of five items that respectively examined students’ views on five constructs concerning the NOS: purpose of science, definition of scientific theory, nature of models, tentativeness of scientific theory, and origin of scientific theory. Students were also asked to respond to an accompanying open-ended section for each item in order to collect information about the rationale(s) for their choices. The results indicated that the majority of Korean students possessed an absolutist/empiricist perspective about the NOS. It was also found that, on the whole, there were no clear differences in the distributions of 6th, 8th, and 10th graders’ views on the NOS. In some questions, distinct differences between Korean students and those of Western countries were found. Educational implications are discussed

Perceived professional needs of Korean science teachers majoring in chemical education and their preferences for online and on-site training

In this study, we investigated the perceived professional needs of Korean science teachers majoring in chemical education, and examined their preferences for online and on-site inservice teacher training programs. The results were also compared with those of preservice teachers. Participants were 120 secondary school teachers and 67 preservice teachers, whose majors were either chemical education or science education with emphasis in chemistry. A questionnaire consisting of a modified Science Teacher Inventory of Need and a section concerning respondents’ demographic information and their use of the Internet was administered. In contrast to previous studies, the perceived needs of Korean inservice and preservice teachers were found to be very strong in all 30 needs assessment items, and their prominent needs were from all seven categories. Preservice teachers indicated significantly greater needs than inservice teachers on several items. Korean teachers generally tended to prefer online inservice to traditional on-site training programs, although they still preferred on-site types of programs in areas such as conducting laboratory sessions and demonstrating manipulative skills. Preferences for online programs tended to be stronger among preservice teachers than inservice teachers, and among non-veteran teachers than in veteran teachers. Educational implications are discussed

Anti-Tumor Effect of Heat-Killed <i>Bifidobacterium bifidum</i> on Human Gastric Cancer through Akt-p53-Dependent Mitochondrial Apoptosis in Xenograft Models

Paraprobiotics, inactivated microbial cells, regulate immune system and exhibit antioxidant and anti-inflammatory activities in patients with weakened immunity or the elderly. This study evaluated the anti-tumor effects of heat-killed Bifidobacterium and Lactobacillus on human gastric cancer MKN1 cells in vitro and in vivo in xenograft animal models. First, cytotoxicity and apoptosis in MKN1 cells of 11 different heat-killed Bifidobacterium or Lactobacillus strains were examined using the MTT assay or flow cytometry, respectively. Then, BALB/c nude mice xenograft animal models were implanted with human gastric cancer MKN1 cells and orally administered a selected single or a mixture of heat-killed bacterial strains to investigate their inhibitory effect on tumor growth. In addition, the expression of p-Akt, p53, Bax, Bak, cleaved caspase-9, -3, and PARP in the tumor tissues was analyzed using Western blotting assay or immunohistochemistry staining. The results show that heat-killed B. bifidum MG731 (MG731), L. reuteri MG5346 (MG5346), and L. rhamnosus MG5200 (MG5200) induced relatively greater apoptosis than other strains in MKN1 cells. Oral administration of a single dose or a mixture of MG731, MG5346, or MG5200 significantly delayed tumor growth, and MG731 had the most effective anti-tumor effect in the xenograft model. Protein expression of p-Akt, p53, Bax, cleaved caspase-3 and -9, and PARP in tumors derived from the xenograft model correlated with the results of the immunohistochemistry staining