Social scientists make many methodological decisions that can influence their research findings and the conclusions they draw about them. Scholars must decide how they will define their key concepts, design survey questions that measure these concepts appropriately, conduct multiple data analyses, decide which analyses make the most sense, and carefully identify the claims that they can make based on the entirety of their research. These challenges apply to all kinds of research, but may be even greater for scholarship that examines LGBTQ populations, as well as other groups that constitute a small percentage of the population. This entry reviews some key methodological issues and highlights one example of research to illustrate key issues that researchers examining LGBTQ populations may encounter and should be especially mindful ...