Design an experiment
Summary
You are to construct a thought experiment on a topic specific to human biology connected to this
class and write a description of it. You’re experiment needs to address a specific, narrowly focused
question, and describe all the components of the experiment. You are not actually going to do it.
But it should be something that COULD be done. This assignment will be revised for a larger
written assignment later.
While your experiment can be based on previous research, your experiment should be original.
You should not need to do any outside research.
You should not worry too much on techniques (see below).
Because it is a thought experiment (and not actually done), ethical considerations can be relaxed (for
now). You can consider using “model systems” (see below).
Steps
For this part of the assignment, you will submit a proposal describing the design of a biological
experiment that is connected to a topic that has been (or will/may/could be) covered in class.
Your proposal must describe 1) what you are planning on testing; 2) why you plan on testing it; 3)
what you hope your experiment will show; 4) roughly how you are planning on testing it; 5) what
your dependent and independent variables are; 6) and all necessary controls.
Considerations
Things to keep in mind: your hypothesis and experiment should be extremely focused and clearly
defined; you should have adequate number of replication of the experiment as part of the
description; your sample size in your controls and treatment groups should be adequate; make sure
your dependent variable actually addresses your hypothesis; make sure you have enough controls to
eliminate other alternate explanations for possible results.
If you come up with an experiment that, after it were performed, one can’t draw any useful
conclusions from it because there were too many unanswered questions, or there were not enough
controls, or because it was a too broadly defined hypothesis or topic, then that experiment was of
little value. With respect to controls, it is common for there to be more than one, as a method to
address potential variables.
Recommended steps:
• Brainstorm a list of topics covered in class. Use your lecture notes, resources posted on
iLearn, or something you’ve read or always been curious about.
• Choose a few topics that most interests you and brainstorm some experiments that could be
done.
• Avoid experiments that are subjective. For example, avoid any experiment that includes data
where you might ask the participants to describe how they feel or that has a survey attached.
Asking if someone “feels better” has too many variables. But you could collect data that
demonstrates “feeling better” like improved performance of a task.
• Of the one you like best, start to craft what the experiment might look like.
• Isolate all the conditions you need to control for. Come up with experimental controls to
avoid those.
• Think of how you can collect measurable data.
• Think about what your data might look like, if you were to run the experiment.
About data
Don’t focus on the technical aspects of how to measure something. For example, say you are
interested in seeing how a molecule affects the brain, with the hypothesis that the molecule reduces
some activity in a region of the brain. In your experiment, you can simply say you introduce a 1x
amount of the molecule, a 2x amount, a 3x or 4x amount, etc…. and you then measure activity in
the brain using imaging equipment. You can also say your molecule has a tracer (like an isotope, e.g.)
so you can follow where it accumulates. Notice you do not have to specify the molecule, the tracer,
or the way you are measuring the effect. You can then give the results (e.g. there was no change in
the region of the brain, but the molecule also failed to accumulate in that region, so it was either not
transported or was metabolized/degraded).
Model systems are a good way to do research. Examples include using cells where you might follow
a response cells have to a new medication. Or using other organisms and non-human animals – for
example, genetic studies often use everything from bacteria and yeast, to worms, fish, mice, etc…
Because this is a thought experiment, and because ethics is less a consideration, these are options to
think about but aren’t things you need to include.
DO NOT PERFORM THE EXPERIMENT!
Submission
Organize your submission using the following headings:
1. Title of Experiment
2. Brief summary of your experiment (see “Steps”) and conclude with a statement of your
hypothesis
3. Description of your independent variable
4. Description of your dependent variable
5. Description of your control group(s)
6. A brief description of how the experiment will be performed, including the data being collected
and how it will be collected.
Again, your written proposal does not require that you do any outside research or gather any
references, although you are welcome to do so. But be sure to properly site your source(s) following
APA guidelines.
The proposal should not be more than 350 words, excluding citations (if any).
Once again, do not perform this experiment!
Grading will be based on clarity of thought, practicality of the experiment, and how well thought out
it is.
In particular, 1) if it is an experiment, 2) how effectively it addresses the topic you select, 3) the
practicality of the experiment and how well thought out it is, 4) the clarity of the submission.
