Developing psychometrically sound instruments can be difficult, especially if little is known about the constructs of interest. When constructs of interest are unclear, a mixed methods approach can be useful. Qualitative inquiry can be used to explore a construct's meaning in a way that informs item writing and allows the strengths of one analysis…

Understanding the reason(s) for Differential Item Functioning (DIF) in the context of measurement is difficult. Although identifying potential DIF items is typically a statistical endeavor, understanding the reasons for DIF (and item repair or replacement) might require investigations that can be informed by qualitative work. Such work is…