The best way to grasp the complexities involved in designing an experiment is to actually do it.
What
Let’s say you were interested in the effects of marijuana on short-term memory. How would you design an experiment to test this? What would you need to consider when designing this experiment? For example, how would you avoid subject biases? That means finding a way to deliver marijuana (or the active ingredient THC) without the subjects being aware of it. And how could you test memory without subjects realizing you were testing memory? Think of this from the point of view of a scientist conducting an experiment in a laboratory or some type of field study. Have fun with this one.
How
Answer the following questions.
How would you deliver marijuana, or the active ingredient THC to your subjects in a way that they would not know they were receiving it?
How would you measure memory without making them aware that that was what you were interested in?

And how would you provide informed consent to your subjects without letting them know it was marijuana or testing memory?
In responding to your peers try to respond to those that had  strategies different from your own. Do you think their ideas would work?
When