M. Silva1, A. Almeida2

1Centro Interdisciplinar de Estudo Educacionais (PORTUGAL)
2Instituto Politécnico de Lisboa (PORTUGAL)
The schooling process includes learning a multiplicity of science concepts. Students have their own distinct ideas about many of these concepts, the so-called misconceptions, which interfere negatively with learning. Learners organize their own daily experiences and interpret the reality around them. However, the use of didactic models not properly interpreted by the students and the non-identification of the previous ideas of the students help to reinforce many of these misconceptions.

The present study involved 38 students from two classes (A and B) attending a state school in Lisbon from the 6th year of schooling in which the Science syllabus is centered on the study of human body systems. Its purpose was to determine:
(i) whether the students possessed any of the misconceptions related to the human respiratory system, referenced in other studies developed in different countries (e.g. air enters and leaves our bodies with no function, air tubes connect the lungs to the heart, the air exhaled is rich in carbon dioxide and poor in oxygen);
(ii) whether a learning design focused on the deconstruction of these misconceptions would be effective to the conceptual change of these pupils.

To this end, the experimental group (class A) experienced a learning design expressly conceived for the deconstruction of the misconceptions related to the human respiratory system while the control group (class B) experienced a traditional approach with interactive lectures and use of the school textbook. The data were collected through a questionnaire applied in two stages (pre and post-test). The questionnaire consisted of open and closed questions and was validated by two experts in Didactics of Science. Pre and post-test results in both groups were compared using a t-test to compare the means obtained by the two groups in the pre-test and to verify the gains of each class between the pre and the post-test. The differences between the groups at the pre-test were statistically non-significant (p = 0.410), an important aspect to better appreciate the gains of each group between the two stages.

After analysis of the results of the pre-test, it was found that the students of the two groups had several misconceptions of the human respiratory system. From the comparative analysis of the means obtained in the pre and the post-test by the experimental group and the control group, both groups had statistically significant differences (respectively p = 0.000 and p = 0.004). Thus, students from both classes decreased the incidence of misconceptions, but the improvement of the experimental group was more significant.

This study allows us to conclude that a design learning process paying particular attention to the identification and deconstruction of misconceptions brings clear gains. Even so, the process experienced by the control group also brought some positive results. Both results support the idea that formal education, if provided with well-structured activities, can contribute to the conceptual restructuring of the students’ mind, albeit with a different rate of success. Finally, the present study also helps to confirm the universality of certain misconceptions. If some of them may be influenced by the cultural context, others seem to be found in samples from different countries, proving that some ideas are common in the human mind independently of the particularities of each context.