Topic models, as developed in computer science, are effective tools for exploring and summarizing large document collections. When applied in social science research, however, they are commonly used for measurement, a task that requires careful validation to ensure that the model outputs actually capture the desired concept of interest. In this paper, we review current practices for topic validation in the field and show that extensive model validation is increasingly rare, or at least not systematically reported in papers and appendices. To supplement current practices, we refine an existing crowd-sourcing method by Chang and coauthors for validating topic quality and go on to create new procedures for validating conceptual labels provided by the researcher. We illustrate our method with an analysis of Facebook posts by U.S. Senators and provide software and guidance for researchers wishing to validate their own topic models. While tailored, case-specific validation exercises will always be best, we aim to improve standard practices by providing a general-purpose tool to validate topics as measures.

Information and communication technologies, especially in the forms of mobile telecommunications, satellite imaging, and geographical information systems, promise to significantly improve the practice of humanitarian relief. A working group convened at the Humanitarian Action Summit 2009, has begun investigating the challenges to implementing these technologies in field operations, keeping in mind the ethical considerations of linking people to place, and pledging to build a community of practice among academics, practitioners, and developers.