This document has several purposes. First, the compendium aims to discuss the purpose of developmental screening and how it differs from child assessment. Second, the compendium aims to "translate" technical psychometric information about the reliability and validity of commonly-used developmental screening tools into language that is easily understood by early childhood practitioners. Being able to access this information more easily can help early childhood practitioners evaluate whether a developmental screening tool is appropriate for the population with which it will be used. Finally, this compendium aims to highlight areas in which the early childhood field is lacking information on reliability and validity of available developmental screening tools. (author abstract)