How does the use of constructive analogies enhance/hinder students’

In phase two of the analysis, we found 29 examples of analogies that had the three characteristics. We found cases where there were only one of the three

characteristics evident, combinations of two of the three characteristics evident as well as cases where all three characteristics were present. There were three examples in which only characteristic 1 was evident and two that were only characteristic 2. There were no examples where only characteristic 3 was present. In terms of the combination of more than one characteristic, there were eight examples of characteristic 1 and 2, one example of characteristic 1 and 3, one example of characteristic 2 and 3. There were 15 examples that had characteristic 1, 2 and 3. These findings are illustrated in Figure 4.

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Figure 4 – Number of constructive analogy characteristics used by participants

Researchers have suggested that the use of analogies or terms associated with analogies such as “it is just like this” or “if you think about it like that” are so

ingrained in human conversations it is easy to develop the ability to compare two similar concepts. Being able to go beyond the comparison of similar concepts gives evidence to higher order conceptual understanding of the target concept (Glynn et al., 1991). This therefore makes the three characteristics discussed as indications of constructive analogies important to be included in analogies used when teaching scientific concepts. Consequently, since more than half of the analogical examples found had all three characteristics the conclusion can be made that there are constructive analogies in the students’ knowledge base. These examples also demonstrate that while analogical thinking or reasoning can be considered commonplace in scientific contexts, the point at which these participants learned these analogies all three characteristics were included. In addition, the second highest combination of characteristics was the eight examples of characteristics one and two. This finding shows students possess the ability to not only identify similar features in

0 2 4 6 8 10 12 14 16 C 1 C 2 C 1, 2 C 1, 3 C 2, 3 C. 1, 2 3

CHARACTERISTICS OFCONSTRUCTIVEANALOGIES INPARTICIPANTS' RESPONSE

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the two concepts being compared but to also discuss how these features map unto each other. In Table 4 below we show examples of three cases of analogy use that had all three characteristics and helped the student’s understanding, had all three characteristics and was reinforcing a misconception and one analogy that was incomplete.

Table 4 – Examples of analogies having constructive characteristics

Analogy had all three characteristics and supported understanding:

So basically with, with DC power, or direct current, it’s kind of like a fire hose, so as you’re pushing a fire hose through, let’s say a small tube, or even a larger tube, it doesn’t really matter, you’re going to have the water that kind of clings to the walls essentially. That’s kind of the general idea of resistance. (1- comparison of power as pressure in a fire hose, 2 – size of tube

compared to resistance, 3 – explains the concept of resistance well)

Analogy had all three characteristics that reinforced a misconception:

So initially if the switch is closed, we’re going to have a voltage flowing through our circuit. You’ll have a current flowing around here. It’s going and, it’s just flowing, flowing, flowing actually–and then when the switch opens, it’s still wanting to flow through it. And so that’s what causes that initial arc. So it’s, it wants to keep going. Like how the switch gets far enough away–that it doesn’t flow anymore. And so the arc is actually just the flow of electrons continuing. So suppose that you have your pipe and you broke the pipe, the water’s still going to flow through it that’s it really. ( A – implied water analogy, B – current movement compared to

fluid flow, C – misconception is reinforced by the analogy)

Incomplete analogies:

There’s a pipe flow analogy that the teacher use in the beginning. And like resistors are like shrinking the pipe, and inductors are, let’s see – like fluid flow, probably like a storage, no that would be a capacitor would be a storage tank, and I don’t remember what the inductor was. But they did have any analogy that like, ‘cause most people take just fluids, they take fluids

beforehand. (A – explicit discussion of water analogy, B – resistor compared to the shrinking of

a pipe, capacitor as storage, C – not evident)

While the presence of all three characteristics in an example indicates the use of constructive analogies, these characteristics on their own do not prevent against students ability to develop or reinforce existing misconceptions. Analogies used in instruction that are not explicitly discussed and explained can lead students to develop misconceptions about the nature of the concept being taught.

I guess I never really used fluid flow analogy, but it helped in describing it to other people. So I guess I kind of already had the idea in my mind before I heard the analogy that went with it, it kind of helps to identify some; might indirectly

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help. But, yeah, there are definitely some things, some circuit components that you can’t describe with a fluid flow; like a transistor, I mean, it just doesn’t have any correlations, so in that sense it could definitely bog you down, but by the same token it can also help you visualize something. And in, when describing to some of my friends as much it, it’s been very beneficial to help them to see it.

Here this student exhibits evidence of meta-cognitive thinking about their understanding of the concepts and their use of analogies. This emerging finding suggests that while it is natural for humans to use comparative language as theorized by Glynn et al. (1991) in some instances students are able to understand on their own that analogies and metaphors do not always completely describe the concept being studied. In the preceding quote it can be seen that this particular student use analogies as a tool to communicate knowledge to others and not necessarily as a method to understand the material. The ability to visualize the concept and to acknowledge this visualization that happened even before the analogy was introduced speaks to this particular participant’s aptitude to reflect on how s/he came to understand.

These findings support the claim that analogies are “double-edged swords” (Glynn et al., 1991, p. 224) in that analogies can be both beneficial and detrimental to the learning of scientifically complex concepts. Overall these findings have significant implications for how analogies are used in instruction.