What is a pre-experimental research design and how does it differ from the main experiment?

[@mohamedaitelhaj3356]

Thank you

[@pallavikarale3577]

How to calculate in social science..sir calculate some examples...thank u sir

[@belloaliyu3310]

Hello, I'm doing my PhD and my work involved a new method of teaching which is targeted at a small group of 8-10 pupils. Can I used pre experimental design as my PhD method?