Polio & Friedman (2016) Chapter 1

   Quantitative approaches and qualitative approaches have different foci. A quantitative approach establishes causal relationships between a practice and an outcome by assigning participants to random groups, designing tasks for them to perform and manipulating variables; a qualitative approach focuses on understanding the process. The approaches to be used depends on the specific research questions and the research stage of a certain field of study. 

    If the research question is about how certain factors can affect the outcome, a quantitative approach should be used; if the process, not the outcome is the focus of the research question, a qualitative method should be used. 

    In addition, whether a quantitative or qualitative approach should be used depends on the stages of the research. For example, if no research has been done in peer review and writing development, and it is not clear what variables in peer review might affect students’ writing development, qualitative research would be very important at this point. Qualitative research can help to understand the process of peer review and provide factors to be analyzed. Based on the results of qualitative research, quantitative research can be done to analyze the relationship between certain variables and the outcome.

    As for the studies mentioned in Polio & Friedman (2016), they approached peer review from different aspects and are both helpful in understanding the matter. Lundstrom & Baker (2009) found that in beginner group, feedback givers got a better score at the posttest(mostly in global skills); Zhu and Mitchell (2012) found that different students have different motives when participating in the peer review activities and the differences in motives affect their interaction behavior during the peer review sessions.

   The studies I have done are mostly descriptive qualitative research and I have never done quantitative research before.