A portrait of Molly

Molly was a Grade 6 girl who initially chose to investigate “Chemical reactions”. Table 4.13 contains the transcripts of Molly’s three videos.

 

Table 4.13

Molly’s video transcripts for “Molecular naming conventions”

Prior knowledge video
Transcript

My topic is chemical reactions.

I don't really know much about chemical reactions but when you put two things together it makes something different, and that's practically all I know.

Completed explanatory animation
Transcript

Atoms are the building blocks of matter. A molecule is a group of atoms. Atoms are sometimes named after the first letter:

H for Hydrogen.

C for Carbon.

They are sometimes based on the first two letters.

Li for Lithium.

Ti for Titanium.

Sometimes the letters have nothing to do with the element.

Au for Gold.

Ag for Silver.

A number following the element refers to the quantity of those atoms.

The number comes after the element.

For example, H2O means two hydrogens and one Oxygen, H2O4S  means two  hydrogens, four oxygens and one sulphur

The order in which the elements are written usually follows the rule developed by Edwin Hill in 1900.   According to this rule, when you have Carbon it goes first, Hydrogen is second and the rest are in alphabetical order.

Director's commentary
Transcript

I changed from topic from “Chemical reactions” to “Chemical bonds” to “Molecular naming conventions.”

I liked how it went and how I made the letters light up when they were mentioned.

Brendan helped me with the animation and I like how he did some of the picturing.

So if you need to ever to learn about naming conventions just go to my animation.

Edwin Hill helped me get this animation correct and helped me get the actual information in order.

 

Introducing Molly and her topic

Molly had a friendly, positive attitude and was always eager to learn and challenge herself with new experiences. Molly was the only 2011 participant who was also involved in the 2010 pilot study. During the first session, Molly got straight to work and devised the following questions as her slide headings:

Slide headings are generally associated with more typical PowerPoint presentations but I knew that Molly was thinking in terms of creating various animation scenes as she had been through this process before. Molly also knew at this early stage that her topic would probably require some tweaking:

Chemical reaction is such a broad topic. I have to find out the basics of chemical reactions and cut it down, to... say... two different things and instead of doing heaps of like...what it is, I should do it like, two different types of chemical reactions and put detail into it. Lots and lots of detail (Student reflection, 21st July 2011).

My own prior knowledge was limited to what I had learnt in High school where I found that I was much better at Physics than Chemistry. I remembered the Periodic Table of the Elements quite vividly and thought that there might be some interesting visual possibilities if we looked at the valency of various elements.

A single animation covering Chemical reactions would always have been too big but we didn't realise how big until later. We considered changing the topic to “Chemical bonds” during the 8th session. This would also have been too big as there were several sub-categories such as covalent, ionic and so on.

 

Creating the ZPD with Molly

Although other students also changed topics during the project, the mutual ZPD that Molly and I were in seemed to revolve around the various discussions about modifying her topic. There was a time when we thought we could come up with a novel way to represent chemical bonds when we first encountered Lewis-style dot diagrams. Figure 4.16 is a Lewis-style dot diagram showing how molecules can be represented as a combination of elements with corresponding atomic bonds.

Figure 4.16

Figure 4.16. Lewis-style dot diagram for water. (Source http://commons.wikimedia.org/wiki/File:Water-2D-flat.png)

These dot diagrams seemed to offer much promise due to their visual simplicity. “It was initially exciting to read that there are pre-existing representation traditions such as Lewis-style dot diagrams. Ideally, Molly would create a new system but this might be unrealistic” (Researcher reflection, 8th September 2011). It turned out that these diagrams don’t reduce the complexity of chemical bonds so we decided to experiment with some other ideas. Molly was very patient and willing to change so we considered using a jigsaw metaphor. Figure 4.17 shows jigsaw pieces with a defined number of male or female parts (1) to represent how different atoms can become molecules depending on their valency.

Figure 4.17

Figure 4.17. Screenshot of discarded jigsaw metaphor 18th August 2011.

I suspect that my incomplete recollection of the periodic table from High school chemistry left me equating this [valency] to positive and negative numbers. I'm now fairly sure that this isn't the case so the jigsaw puzzle imagery from last week is not the best representation for this concept. There is a money analogy that I'll mention [during the next session] as one possible alternative. It involves various denominations of coins that can be combined to add up to one dollar (thus avoiding negative numbers) (Researcher reflection, 25th August 2011).

When I suggested that positive and negative might not be appropriate terminology, Molly was very gracious, considering that it was I who had first suggested these terms only a few weeks earlier. I noted that the “new analogy of various coins making up a dollar was well received so this could be our way forward” (Researcher reflection, 1st September 2011). Molly appeared to have no trouble abandoning the negative and positive terminology saying, “I realised that you can't do positive and negative for my presentation because there's no such thing in chemical language about positive and negative” (Student reflection, 1st September 2011). Further reflection about the validity of negative and positive caused me to wrestle with the issue of whether I could really support Molly with her topic as noted in my Researcher’s reflexive journal, 17th October 2011:

I am considering whether Molly might be better changing to a completely different topic such as the musical rhythms of swing and straight. She is the only Storyboard 2011 participant who was also part of the 2010 pilot study and her topic then was the musical convention of “Sharps and flats”. Not only would a new topic be easier, but I read a statement in the International Handbook of Research on Conceptual Change (2008) that made me question my ability to be of real assistance to her. "Instructional approaches compound the problem when they present the tenants of the atomic molecular theory as a set of facts rather than as an explanatory model" (Wiser & Smith, 2008, p. 220).

My self-doubt occurred during Molly’s one-month absence (i.e., two Storyboard sessions and two weeks of school holidays). “I spoke to Molly outside of a Storyboard session as I hadn't had the opportunity for over a month. She wanted to keep a chemistry focus so we are looking at Chemical bond naming conventions" (Researcher’s reflexive journal, 18th October 2011). Ultimately, a topic change was in order and having found Hill's rule, we were finally confident that we had a topic that could be adequately covered. Our goal was to simplify the topic without being simplistic.

 

Molly’s conceptual journey

When the topic evolved into “Molecular naming conventions”, the previous metaphors were abandoned as they were no longer relevant. These discarded metaphors, however, had still served a valuable purpose for Molly’s learning as they provided a context for us to articulate the variables involved in her topic and to discuss how these might fit together as a model. This approach was consistent with the notion that “chemistry as a discipline is dominated by the use of models and modelling” (Coll & Taylor, 2002, p. 175).

To assist with model development, I introduced Molly to Hill’s rule for naming molecular bonds. This consisted of three short guidelines that Molly was able to include in her reference slide (i.e., the final frame at the end of an animation where information is left on the screen for possible use in classroom discussion). Figure 4.18 states Hill’s rule as three sequential guidelines:

Figure 4.18

Figure 4.18. Hill’s rule as a concluding reference frame.

The animation task for Molly then became a process of reverse engineering where she could devise the most affective way the lead up to Hill’s three guidelines. Molly introduced her animation by stating that, “Atoms are the building blocks of matter” (“Molecular naming conventions” animation). Figure 4.19 depicts literal building blocks containing the chemical element abbreviations accompanying the figurative speech of Molly’s voice-over script.

Figure 4.19

Figure 4.19. Opening screen shot from “Molecular naming conventions” animation.

The notion of atoms combining and bonding into molecules was then handled without reference to electrons or valency. The main consideration was now about achieving visual clarity. “Today I experimented trying to find which colours would suit the elements for highlighting” (Student reflection, 8th December 2011). Figure 4.20 shows how the red oval shape acts as a grouping device for the chemical element symbols:

Figure 4.20

Figure 4.20. “Molecular naming conventions” screen shot 8th December 2011.

The decision to use the names and corresponding abbreviations for the elements, rather than attempting to represent them graphically, made the task more manageable. I noted that labelling and naming appears to be one of the easiest representational tasks as this process is often arbitrary:

Molly's reflection about how she is going to "write the atoms instead of drawing them" is actually quite profound. Far from language being the ultimate form of expression, Molly chose words as an easier option than the more difficult task of representing atoms by drawing their structure (Researcher reflection, 20th October 2011).

During the debriefing session, Molly had some insight and opinion about the issue of the ideal class size for this project:

Brendan: I mentioned to you all that umm, that last year I did the same project but the difference was I didn’t get the information along the way. I just got the final animation, right? Two things about the comparison between them and you: Firstly, I told you that there were eighteen of those children.

Molly: And I was one of them.

Brendan: And you were one of them. Do you have any comment before I say another word?

Molly: I like it with eight people because it’s more...

Maria: Individual.

Molly: You get to go, you get to learn more and you’re more...

Sunny: Focused.

Molly: You’re more "in it" and get to know people better.

Brendan: There were a few times like with Grade 5 camp that only half of us were here and I think that was even better.

Molly: Yeah (Debriefing session 1C, December 15th 2011).


I have since concluded that a class size of four would have been optimal. Table 4.14 is Molly’s final conceptual consolidation rubric.

 

Table 4.14

Molly’s final conceptual consolidation rubric

Uses correct terminology With assistance Simplified terminology Some correct terminology Actual terminology

Identifies relevant variables

Not apparent With assistance Basic understanding

Deep understanding

Identifies relationships between variables Not apparent With assistance Basic understanding Deep understanding

Self-assessment scale (1-10). Does the student think that they understand their topic?

1
2
3
4
5
6
7.5
8
9
10

Molly’s modest self-assessment score of 7.5 may have been because she realised how difficult chemistry can be and remembered how much of the initial research was too difficult. My assessment in the first three rows of her rubric was higher than Molly’s self-assessment, as I looked at the topic that she actually presented. In that regard, Molly would agree that she understood her topic clearly, stating confidently, “if you need to ever to learn about naming conventions just go to my animation” (“Molecular naming conventions” director’s commentary).

Molly’s director's commentary was the only one where we changed the video footage from the completed explanatory animation by speeding up one passage. This was because we didn't need as much time at this point to accommodate Molly’s comments.

A summary of Molly’s conceptual journey is presented in Table 4.15.

 

Table 4.15

Summary of Molly’s conceptual journey

Table 4.15

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(1) The terms male and female are used here in a similar way to electrical audio connections where the male parts are extended and the female parts are recessed.

 

Proceed to the next Portrait of Ingrid

 

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