IB ESS 1
I.A. #2: Abiotic Factors Affecting Productivity
Information Provided by Teacher: Productivity of an ecosystem may be determined by various indirect
and direct methods. In this, first, piece of work you will create for your IB internal assessment portfolio,
you will set out to measure how abiotic factors affect the productivity of a named ecosystem.
Time:
Begin on October 23, 2008
Preliminary Plan Due: October 29, 2008
Data Collection Complete: November 7, 2008
First Draft Peer Reviewed: November 12, 2008
Final Draft Submitted: November 18, 2008
Process: Most of the work on creating a good experiment is done in the planning stages, before you
even do the set-up. Remember the adage: “Garbage in, garbage out.” Follow the criteria on the IB
rubrics and the “Guidance on the criteria” document. Basically, you’ll need to think about abiotic
factors that affect the productivity of a particular ecosystem. You need to select one factor that you can
manipulate while controlling all other variables. Background research needs to be done so that you
have an understanding of the processes involved and can form a hypothesis. You must be able to
measure productivity in the ecosystem you choose in a practical way and collect multiple data points
over the time allowed.
You’ll need to think specifically beforehand about the kind of data you want to collect that will help you
make a decision on whether the hypothesis is supported or rejected. The data you gather need to be
processed and presented appropriately according to the IB criteria and you need to provide written
analysis discussing what they mean. It’s also essential that you consider here the numbers themselves
and the error of uncertainty built into your measurement procedure. How “different” do the numbers
need to be before you can say they are “meaningfully different?” Use the data to make conclusions
about your hypothesis and suggest limitations, and improvements to your experiment.
Preliminary Planning Sheet
What is your research question?
What bits of information do you know/have you gathered/do you need to look for to help you
understand the question?
What are 2 possible hypotheses?
1
2
What is your manipulated variable? How will you manipulate/control it?
What is your responding variable? How will you measure it?
What uncertainty is inherent in your measurement procedure?
What factors do you need to consider and control? How?