How do I know what research design to use on a Psychology research paper?

I am writing a research proposal comparing the IQ of two different groups. There is no intervention or treatment, just comparing the groups as is...ANY help, as soon as possible would be GREATLY appreciated!

How do I know what research design to use on a Psychology research paper?
Such psychological research would most likely require surveying (to obtain demographical data to aid in developing conclusions on the two groups' similarities and differences) and testing to determine their actual IQ. I imagine this could include using experimental procedures to test IQ, but the more traditional approach to testing IQ is using the appropriate test to survey the two groups.
Reply:Use the APA format and the design would depend on what kind of methodology you are using to collect the data. I like the feminist methodology because generally with psychology I like to be at the same level as the people I am interviewing or polling. I find that I collect more data that is honest and not contrived. Try quantitative as they may be easier to gather the initial findings needed to do a comparison.