Internal Assessment
Internal Assessment in Science Subjects – Biology
(24% of final grade)
Design – D
Aspect 1
Aspect 2
Aspect 3
Defining the problem and selecting variables
Controlling variables
Developing a method for collection of data
What IB want
Formulates a focused problem/research question and identifies the relevant variables.
Designs a method for the effective control of the variables.
Develops a method that allows for the collection of sufficient relevant data.
What you have to do
Research question: You must state exactly what it is you are going to investigate.
For example if the task set by the teacher is to investigate factors affecting enzyme action your research question must state which factor, the name of the enzyme and the reaction it catalyses.
Hypothesis: write a hypothesis based on your knowledge of the topic. This means what you expect to happen in the experiment. You can include a sketch graph if it is relevant.
Identifies variables: Variables are factors that can be measured and/or controlled. You must state what variable you are changing, this is the independent variable (x). When you change the independent variable the dependent variable (y) changes. This is the one you measure. All other variables will be kept the same and must be controlled because you can only change one variable at a time in an experiment.
For example if you are investigating the effect of pH on an enzyme pH is the independent variable, the dependant variable could be the time taken for the reaction. Controlled variables would include temperature and volume and concentration of solutions. You must state exactly how you are going to control each of the variables you listed in aspect 1 when you carry out the experiment. If it is not possible to actually control the variables you should state how you are monitoring them.
For example: temperature keep constant using a water bath, volume : keep constant by using a measuring cylinder.
Time: use same stopwatch, have same person
(24% of final grade)
Design – D
Aspect 1
Aspect 2
Aspect 3
Defining the problem and selecting variables
Controlling variables
Developing a method for collection of data
What IB want
Formulates a focused problem/research question and identifies the relevant variables.
Designs a method for the effective control of the variables.
Develops a method that allows for the collection of sufficient relevant data.
What you have to do
Research question: You must state exactly what it is you are going to investigate.
For example if the task set by the teacher is to investigate factors affecting enzyme action your research question must state which factor, the name of the enzyme and the reaction it catalyses.
Hypothesis: write a hypothesis based on your knowledge of the topic. This means what you expect to happen in the experiment. You can include a sketch graph if it is relevant.
Identifies variables: Variables are factors that can be measured and/or controlled. You must state what variable you are changing, this is the independent variable (x). When you change the independent variable the dependent variable (y) changes. This is the one you measure. All other variables will be kept the same and must be controlled because you can only change one variable at a time in an experiment.
For example if you are investigating the effect of pH on an enzyme pH is the independent variable, the dependant variable could be the time taken for the reaction. Controlled variables would include temperature and volume and concentration of solutions. You must state exactly how you are going to control each of the variables you listed in aspect 1 when you carry out the experiment. If it is not possible to actually control the variables you should state how you are monitoring them.
For example: temperature keep constant using a water bath, volume : keep constant by using a measuring cylinder.
Time: use same stopwatch, have same person