This report provides the theoretical, technical, and empirical foundations of the Desired Results Developmental Profile(C) (2010) (DRDP(C) (2010)), and summarizes information documenting the validity and reliability of interpretations and use of ratings from the Desired Results Developmental Profile - Infant/Toddler(C) (2010) [DRDP-IT(C) (2010)] and the Desired Results Developmental Profile - Preschool(C) (2010) [DRDP-PS(C) (2010)]. Validity and reliability for the DRDP(C) (2010) were evaluated by the Berkeley Evaluation and Assessment Research Center (BEAR) at the University of California, which analyzed the results of a comprehensive research study involving a large, diverse group of teachers and students. Findings of the study are based on sources of evidence supporting the validity, reliability and fairness of inferences as established by the Standards for Educational and Psychological Testing ("The Standards") (American Educational Research Association (AERA), American Psychological Association (APA), National Council of Measurement in Education (NCME), 1999). The Standards define validity as "the degree to which all the accumulated evidence and theory supports the interpretations of test scores entailed by proposed uses of tests" (AERA, APA, NCME , 1999, p. 9). For purposes of this report, the term "scores" is replaced by the word "ratings." (author abstract)