In this report, we highlight findings from cross-cohort analyses of data from the Head Start Family and Child Experiences Survey (FACES) 2006, 2009, and 2014. The analyses (1) provide a descriptive portrait of observed classroom quality and other relevant classroom, teacher, and program characteristics at each time period; (2) determine the existence of trends or patterns in observed classroom quality and selected classroom, teacher, and program characteristics across cohorts; and (3) examine whether changes in such characteristics can explain the trends in observed classroom quality fully, partially, or not at all. We first describe the research questions the analyses are intended to address and then provide a brief overview of the FACES design across cohorts, including a description of any caveats related to the instrumentation and sampling across cohorts. Next, we describe our analytic approach and summarize findings from each analysis. We conclude this report with a discussion of the implications of the findings for future research. A companion policy brief (Aikens et al. 2016), also highlights a subset of the current findings. (author abstract)