Research Question

#1
Hey Everyone hopefully you can help me. My last hope ;-). For a Stat's and Research Exam (on Monday) I need to answer the following questions:
Draw a diagram to illustrate the stages of the research process. Explain function and purpose of each stage.
Note: I know the diagram but I'm really struggling with the function and purpose.

The second question is:
Define validity, reliability and accuracy. Briefly outline how each stage of the research process contributes to ensuring a research project is valid,reliabale and accurate.