Medical imaging is a topic in which students might have some preconceived ideas and models because of their own or somebody from their family’s medical experience. They will almost certainly have heard something about it.
General common students’ ideas identified by Science Education Research around Sound are:
- Sounds can travel through empty space (a vacuum).
- Sounds cannot travel through liquids and solids.
- Sound moves faster in air than in solids (air is "thinner" and forms less of a barrier).
- Ultrasounds are extremely loud sounds.
It is quite difficult to find research on students’ understanding of ultrasound, X-rays and CT scans. This is probably because these topics are not covered in regular physics curricula.
Almost all of the students either have undergone some ultrasound of X-ray procedure in their lives or know of someone who has.
The studies by Kalita and Zollman [1] showed in their research that
“… students transfer pieces of knowledge from very different sources such as their own X-ray experience, previous physics and other science courses and mass media. This transfer results in mental models that are not necessary stable, consistent or coherent.”
These models should be taken into account.
Some general common students’ ideas around Radioactivity [2], [3] are:
- Radiation is always invisible.
- Light is different that radiation.
- Radiation is mostly artificial.
- Radiation is bad for our environment.
- Factories emit harmful radiation.
- All electrical devices emit harmful radiation.
- X-rays are not dangerous because doctors use them.
- Atoms cannot be changed from one element to another.
- Radiation causes cancer, thus it cannot be used to cure cancer.
- Once material is radioactive it is radioactive forever.
- Objects exposed to radiation would either become sources of radiation or have radioactive properties.
- Either the mass and/or volume of a radioactive material would decrease by half in the period of a half-life. Using such terms, as radioactive ‘decay’ seemed to suggest that the atoms disappeared so even for those students who did have an understanding of radioactivity that involves the atom, they often also predict that half of the radioactive object will disappear after a half-life.
- S.Kalita, D.Zollman, Investigating Students’ Ideas About X-rays While Developing Teaching Materials for a Medical Course, Proceedings of the Physics Education Research Conference, 2006
- S. Neumann, M. Hopf, Students’ Conceptions about ‘Radiation’: Results from and Explorative Interview Study of 9th Grade Students, J Sci Educ Technol (2012) 21: 826-834
- http://www.ase.org.uk/resources/scitutors/subject-knowledge/k46-radioact...