This paper begins by discussing some of the issues that arise when conducting research with young DLLs and the challenges that result from the lack of high-quality, validated assessments in multiple languages. The First 5 California DLL Pilot Study (www.californiadllstudy.org) serves as a case study of how these issues and challenges might be addressed. Next, this paper will explain how researchers on the First 5 DLL study have responded to the lack of high-quality assessments in multiple languages by instead using assessments that have either been translated or adapted, again presenting the First 5 California DLL Pilot study as an example. However, these approaches (adaptation and translation) are not perfect and so this paper will go on to help current researchers who use these solutions avoid important pitfalls. Finally, we conclude with a call to action and discussion of possible next steps. (author abstract)