Scientific investigations generally focus on the cause/effect relationship
between two variables. Change one aspect of the situation and see how another
is effected. Deciding what variables to investigate is a major part of defining
the problem. For example; you might be interested in the effect of putting
ice inside the incubator. For example, how does the temperature depend on
the amount of unmelted ice remaining in the incubator.
Once you have chosen the independent variable (cause) and the dependent
variable (effect), you can decide how the change the independent variable
(like the amount of ice) and how to measure the dependent variable (like
the temperature). It is a good idea to set up a table for recording measurements
as you change the independent variable. A graph helps with the visualization
of the relationship and may lead to a mathematical model.
Plan your extension so your report will have diagrams, tables, graphs, calculations,
Talk through your ideas with your teacher and make a plan before you begin
to experiment. Once experimentation starts you will probably want to revise
your original plan.