‘If I had to reduce all of educational psychology to just one principle, I would say this: The most important single factor influencing learning is what the learner already knows. Ascertain this and teach them accordingly’
(Ausubel, 1968)
(Ausubel, 1968)
The complex and abstract nature of Chemistry tends to result in students holding a variety of alternative conceptual ideas that differ from the commonly accepted scientific consensus. In the literature, these are generally referred to as misconceptions or alternative conceptions.
I am undertaking an education focused MSc degree investigating how Chemistry students’ alternative conceptions can be exposed and challenged. Alternative conceptions can be exposed using diagnostic tools such as student -generated drawing tasks and concept inventories, both of which I will discuss in more detail below. To challenge students’ alternative conceptions, I am investigating cooperative learning as a pedagogical strategy.
Concept inventories
A concept inventory is a multiple choice instrument composed of non-mathematical conceptual questions. One answer is correct while the other answers (called distractors) are alternative conceptions derived from research.
Below is an example of a concept inventory question. First year Chemistry students at Monash were invited to answer this particular question at the start of semester 1, 2013. Before reading further, what answer would you choose?
Students with a good conceptual understanding of what happens during a phase change would have recognized that (e) was the correct answer. However, only 45% of students who responded chose (e). Therefore, more than half of the students thought that when water evaporates it results in the formation of oxygen and hydrogen atoms or molecules. Or worse still, rather than just being spaced further apart, the molecules disappear altogether!
Student generated diagrams
Knowledge and understanding of Chemistry is generated, expressed, taught, and communicated at the macro, submicro and symbolic levels of representation (Johnstone, 1991). These three levels of representation are briefly described in the table below.
Research data I have collected to date highlights the diversity of students’ submicro representations for the same substance. Below are examples of first year Chemistry students’ drawings of water molecules.
However, does a student-generated drawing that lacks detail or is inaccurate mean that they hold an alternative conception? Maybe they have an understanding of a concept that they have chosen not to include in their diagram or maybe they were just being ‘lazy’?
Chemistry is a visual science, and chemists have developed a variety of representations to help understand and communicate information that may not be easily understood otherwise. I believe it is of pedagogical significance for Chemistry students to generate their own submicro drawings and use them to facilitate a shared understanding with their peers.
References
Ausubel, D. (1968). Educational psychology: A cognitive view. New York: Holt, Rinehart & Winston.
Johnstone, A. H. (1991). Why is science difficult to learn? Things are seldom what they seem. Journal of computer assisted learning, 7(2), 75-83. doi: 10.1111/j.1365-2729.1991.tb00230.x
(c) is a perfectly accurate 'to scale' diagram of water in the gas phase, showing the statistically most-likely image if the container is not a closed system. (It may be implied that it is closed by the picture, but not stated explicitly). As a pedant with twenty years experience of teaching chemistry, I would definitely pay (c).
ReplyDeleteHi Dr Clam. This question does explicitly state that 'The circle on the left shows a magnified view of a very small portion of liquid water in a closed container'. I agree though that without this qualification (c) would be a valid 'to scale' answer.
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