Tutorial Three - Chemistry

In this tutorial we split into groups to look at different experiments that could be used within a science class. But these were not te usual experiments. Instead we had to either design our own method or work through the theory before we did the experiment.

My group looked at acid and base chemistry. We started with a thinking task which got us to move through the chemistry behind the experiment before we started. This was really interesting seeing we had all forgotten acid-base chemistry!!

The questions created a good discussion within our group about how we know if a student has a good grasp on the concept. What had happened in the group was we had come across a question which asked us to calculate the volume of HCl needed to neutralize 20cm3 of NaOH.
None of us could remember what to do. We got an answer at one stage of 1000L! After spending a considerable amount of time on this some of us moved on to the next question so we didn't sit there all class. I felt this question was more conceptual. We were able to come up with an answer without having any of the maths under control.
This created a question about if students needed to have completed both questions successfully to have demonstrated that they understood the topic. At the time I felt that if students could use logic to come to an answer I would be satisfied that they understood what was going on.
Another member of our group felt that it was critical that they could do the maths because being 1:1 mole relationship they may not understand what was occuring and still guess right.

I found this fascinating, because it really got down to the idea that I have tried to touch on before (both here and MUSO). So what is learning and how do we know when it has occured. Is it necessary for students to have all parts together or is it okay for students to demonstrate skills in only one area.

In the end we decided that it would have been more informative for a teacher about the students' knowledge if there had been a different mole ratio. Both of us would have been satisified that the student understood what was occuring if they could used logic to find the answer.

Deb also pointed out something useful. That perhaps these tasks were good at pinpointing where the student is having difficulties. By allowing a student tasks that require maths and tasks that require logic you could get some understanding about how a student thinks. They may be brilliant at the maths but have no understanding about phenomina occurs. So they may get the right answer but no understand what had occured. Or they may have a good insight to the theory about the phenomena but lack the math skills to get the right answer.

We also commented that the thought questions before the experiment was a good idea because students would be expected to have some understanding about what was occuring before they started the experiment. In this way students could ask questions before or during the experiment, instead of discovering during the write-up that they have no-idea what just occured.

We did have the problem that our group split totally during the tutorial. One half insisted on completing the maths before moving on, while the other half pushed through what they could then started the experiment. I found this interesting to think about because of the implications that it may have in class. It is very likely that given a set of thinking questions students may take the whole lesson to complete the task and never have time to complete the experiment. In a classroom you don't want to have to run the experiment two or more times.
Deb suggested that these questions would be more appropriate for students to complete at home or before the lab class. This way all students should be ready to start and have time to complete the experiment.
There is the possibility that students will not complete the questions. In my class I agree with Deb an students would have to miss out on the lab while they finished their homework. This would show students that I expected them to complete it. If they are allowed to continue without having attempted the questions, less and less students would attempt them, until the exercise of having pre-thought through the theory would be lost.

Keasty (in a previous year) also mentioned that he often gives the prac out to students before the lesson. (In experiments where students have to follow set instructions.) The instructions are jumbled and students are expected to unjumble them. This could allow younger students to think about the logic of why certain steps occur in the order they do.

In the last hour we worked again on our unit of work. It is really difficult to do.
I am finding that I have trouble designing work with other teachers because we have different expectations of what we would want students to do. There is alot of comprimise in group designing and it could be extremly difficult if you teach in totally different ways.
I can also see benifits to this work, but it is definatly a developed skill and not an easy process.