Mini summer project - Developing enquiry through practical work

Through my masters myself and others have found that while students enjoy practical work, they may not understand why they are doing it or what their results show,

While teaching on the summer school I have been experimenting with an introduction to the IB group.  The students are unknown to me before the week starts, and most of them I will never see again, my class is mixed ability and mixed nationality.  Students haven't normally done much if any practical work. 


I experimented with changing the way I normally teach by first doing the practical work and then asking students to derive the variables and the reasons behind it.  Normally I would teach the content

I chose two simple experiments, one looking at mass loss in different leaves, and the second looking at the affect acid has on seed germination. 

In the first hour students set up the experiment

Transpiration - students weighed 5 different leaves from different species and pegged them on a clothes line, 

Germination - students made serial dilutions of acid, and added it to 5 petri dishes containing filter paper.  Each petri dish contained 10 rocket seeds.

In the second hour students were introduced to variables and then asked to identify the dependent, independent and controlled variables.  I used think-pair-share and then wrote their answers onto the board.

Enquiry

I found enquiry difficult to observe, however through group work I noticed that by giving students time to think through things on their own and to jot down their ideas they were much better at participating and more importantly questioning each others’ answers.  Although an obvious point, I must remember to give students enough thinking time before I ask them to contribute their ideas.  In the interview one student made the comment that she preferred the way we had done the experiments because it had forced her to think about her ideas, whereas normally she read the sheet and didn’t remember anything afterwards.

To develop enquiry further I think I would need a much more specific idea of what I wanted from my students.  During the tasks I identified enquiry as talking through their scientific ideas and questioning each others ideas.  However this is quite limited because it doesn’t take into account the work they did individually.

Understanding

Students completed their work on germination and transpiration easily.  When I asked them about it many had studied these topics before and helped other students with the subject specific questions.  From the interview students said it was useful to be given questions to make them reflect on the experiment as often they completed practical work without knowing why and what they were doing.  So although they were unsure while they were completing the experiment the reflection time and questions afterwards meant that they all made progress in why they were doing the experiment.

Other points

The interview also identified a common complaint which was that students were always made to complete full write ups, which took them so long that they started to dread doing practicals because of their resulting homework.  By making their homework questions shorter after having processed the data in class they felt they had gained a better understanding of the science.

Despite the long homeworks another student said that in order to develop enquiry skills they needed to do more of them.  One student also got frustrated when she did practicals that didn’t have a clear change, she enjoyed the germination experiment because she could see a definite change at the end of the week.  

I still have a way to go to make sure that all of my students are understanding the point of practicals and developing enquiry skills through practical work, but I was pleased with the progress the students made over the week.   I am now much more aware of developing inquiry skills and in the future I will be more careful about choosing post-practical questions to develop enquiry.  

There also needs to be a balance between developing practical write ups skills to get good marks in internal assessment and using practicals to develop scientific understanding.  In the future I will stress the difference to my students, so they don’t see practical work as a cause of lengthy and pointless homework.