AP Biology
Pre-lab expectations
In future investigations you will be expected to demonstrate your understanding of the experimental design (and
yes, you do need to read the lab overview and procedures before you partake in the lab). The artifact of your
understanding will be in the form of a Pre-lab Flowchart This flowchart will help you identify the components of your
investigation. The format can be in diagram or outline form.
This Pre-lab Flowchart will be checked off by your instructor at the beginning of the class and will be
evaluated on completeness and accuracy. Your flowchart is to be included in your e-Laboratory Investigation
Notebook. You should be prepared on the scheduled lab day to answer questions about the investigation.
Pre-Lab Flowchart
Purpose or Question
and
……
.
Experimental design
(between dashed lines)
If…
…
ControllED Variable(s)
(constant across treatments)
(identify at least 3)
Hypothesis
Dependent Variable
(what you are measuring)
“changed” X axis
Y axis
Procedure
“methods”
then..
Independent Variable
Treatments
levels? control?
Predicted Result of Experiment
Form, then wait and see (oh..the suspense!)
00000000))ssuspense!)
And/But…
Observed Result of Experiment
therefore…
Conclusion
Run experiment
multiple times
(trials or
replicates)
Experimental Design…some definitions.
Purpose or question: identify the question(s) that is to be answered by this scientific investigation or the
purpose of the scientific investigation. This is usually found in the “Overview” section of a standardized AP
laboratory handout.
Identify
Hypothesis: a tentative, explanation for what you observe.
Develop
Experimental design: how you will go about testing your hypothesis. Most often, the main purpose of your
design is to test the effect of the independent variable on the dependent variable.
Variable: a characteristic that varies from one biological entity to another (Zar, 1984). There are three
categories used in an experimental design: independent, dependent and controlled.
Dependent Variable: the variable you are measuring (what you count or record in your data table).
Identify
Independent variable: the variable that you vary (manipulate) during the experiment. It is the variable that
you think will affect the dependent variable.
Identify
Treatments: appropriate levels (values) that you assign to the independent variable. These are usually defined
for you in your AP lab handout.
Set
Controlled variable(s): all independent variables other than the one being studied that are to be held constant.
Identify
Procedure (method):an explanation of how you will measure the dependent variable in your experiment, what
the levels of treatment will be for your independent variable and how you will keep the controlled variable(s)
“constant”. Methods are outlined in the “Procedures” section of a standardized AP lab handout. This section
should be written so that anyone could repeat your experiment exactly as it was run and that it is replicable.
List Steps
Prediction: the expected outcome of your experiment. In other words, your “educated guess”. Must be based
on your hypothesis to be valid.
Form, then wait and see (oh.. the suspense!).
AP Biology e-Laboratory Investigation Notebook- Google Doc Style
Pre Lab Flowchart Template- Outline format
AP Biology Investigation:
Primary question(s) investigated:
*Specific experimental question(s)
Hypothesis:
Independent (manipulated) variable:
Levels of treatment (include control treatment if applicable):
Dependent (responding) variable:
Controlled Variables:
Concise conceptual summary of methods and materials you will use:
Predicted results:
*If multiple questions are being investigated for this investigation please copy the template above to
address each experimental design you will use to test this question.