Longer ago than I care to admit a popular educational resource for kids was a series of Bell Telephone sponsored films on a variety of science topics. The series was made for TV in the mid to late 50s and later distributed to schools. The one I remember best was Hemo the Magnificent. It combined humorous Disney style animation with human actors to take the student on a virtual tour of the circulatory system. Clever production elements and analogies (such as nervous pathways illustrated by telephone lines and little men operating levers representing pre-capillary sphincters) held us baby boomers in rapt attention and indelibly etched the circulatory system in our minds.
Fast forward to generation X and this paper in Advances in Physiology Education. The survey of undergraduate students found a high rate of misconceptions about circulatory function and offers fascinating insight about how we learn. When asked to trace the flow of blood a student might draw a path around the perimeter of the body. When asked about the principal function of the lungs some students said it was to filter the blood, others said to convert oxygen into carbon dioxide. There was confusion about distinctions between arteries, veins and capillaries. Worse, these college students were pursuing a career in elementary education.
Despite improvements over time major misconceptions persisted through the end of the course. Equally concerning was the fact that one on one interviews with students uncovered many more misconceptions about the circulation than standard tests, suggesting that students can conceal major areas of misunderstanding on routine testing.
The authors point out that faulty preconceptions about course material hinder learning. Learning is a synthesis of new content and what the student thought before. If the student’s prior thoughts are flawed the learning is less effective. The discipline of physiology, the study of how the body works, may be uniquely susceptible to prior thinking. Early on children begin to develop a mental model based on their interpretations of body sensations. Although the model becomes more sophisticated over time it remains flawed. The teaching of physiology might be more effective if teachers could identify student misconceptions, then employ means to help students unlearn or modify them. The authors conclude that new methods of assessment and teaching are needed. I would add that perhaps we should resurrect Hemo the Magnificent.