The main purpose of this study was to determine whether early childhood classrooms can be grouped based on their scores on multiple measures of quality. The study team also examined the number of classroom quality groups that exist and the percentage of classrooms that fall within each classroom quality group. This study employs a methodological approach that has not previously been used to synthesize measures of classroom quality. This approach, known as latent class analysis, allowed the study team to uncover hidden patterns of classroom quality in data collected from programs serving Head Start-eligible children across the country. In addition to informing practitioners about what quality looks like in these settings, the findings allow for the categorization of classrooms across multiple classroom quality dimensions. This is more useful for informing practitioners than the traditional way of measuring quality along a single continuum--eliminating the need for users to come up with their own cut scores for these measures. A second purpose of the study was to explore the extent to which each measure contributes to the identification of classroom quality groups. (author abstract)