Answer:
There are many different methods of experiments. I would have been able to help you more if you were more specific. However i can tell you that, there are different types of methods for everything. For instance when studying the brain psychologists may use methods like the CAT scan, PET scan, MRI scan, and even the EEG scan. All scans are used for different operations.
Also keep in mind that experiments are not always to take place inside a lab. For instance a rat does not always act the same as it would outside, inside a lab. So in some experiments psychologists choose to do their study outside the lab for more accurate results.
Hope this helped.
- Azad