This seems like a good overview of quantitative social science research, but I think it's important to recognize the value of qualitative research, as well. When we have a model and a hypothesis to test, quantitative research is the right tool. When we don't yet understand a problem well enough to have a model or a testable hypothisis, detailed, thorough qualitative observations can help to generate a model or hypothesis. On the other hand, quanitative research can confirm a statistical relationship, but usually cannot prove causality, particularly in the social sciences, where exogenous factors are common and setting up a true randomized trial is often impossible. Qualitative research helps us to complete the cycle and interpret the results we obtain from quantitative relationships.