Background: Decades of research suggest that when young children are enrolled in high-quality pre-K classrooms they have better literacy, language, math, and social outcomes at the end of the pre-K year. A traditional approach to capturing the quality of children's experiences, including the quality of their engagement with academic content and with teachers in a classroom focuses on average classroom quality levels. This approach, however, may not capture the variability in the quality of classroom experiences individual children encounter. This study proposes to examine the variability of the quality of children's engagement in academic content and with their teachers, and the degree to which variability in addition to total proportion of time spent in academic content contribute to children's school-readiness outcomes. We also explore a novel approach to examining variability as the actual incidence of academic engagement is quite low for individual children enrolled in pre-K classrooms (Early et al., 2010). The examination of individual variation in pre-K classroom experiences is particularly important as we deconstruct systemic racism built into a one-size-fits-all approach. For example, African-American children were enrolled in classrooms with more didactic instruction, which may be influenced by the beliefs of the teachers, schools, and cultural communities within which these children are enrolled (Howes, 2010). Hispanic/Latinx children are also more likely to be engaged in language and literacy activities, but less engaged in science activities than their non-Hispanic/Latinx peers (Early, et al., 2010). Accounting for individual variation and opportunities for improvement are an important component of equitable, effective pre-K experiences. Purpose: The purpose of this study is to explore the variability of individual children's engagement with teachers and engagement with academic content, whether it relates to children's outcomes, and whether it is moderated by children's dual language learner (DLL) status and by being a Hispanic/Latinx or African American child with a teacher of the same race/ethnicity and language background. Setting and Program: This study draws from three datasets that represent children's pre-K experiences in varied locations across the country: Multi-State, SWEEP, and LAExCELS. Participants: Both studies included direct classroom observations, time-sampling of child engagement and child assessments and have representation of families from middle- and low-income socioeconomic contexts, as well as racial, ethnic, and linguistic diversity. A total of four children per classroom were selected using a stratified random sampling approach resulting in a sample of 701 programs and classrooms across studies, and 2,962 children in the Multi-State and SWEEP datasets. Research Design: All children from the original studies were included in the secondary data analyses unless they attended a classroom where no observational data of child engagement, environmental quality, or teacher-child interactions was collected. Data Collection and Analysis: An intensive time-sampling measure of individual and group-level engagement was used in all three studies, the Emerging Academics Snapshot (Ritchie, Howes, Kraft-Sayre, & Weiser, 2001), and is comprised of academic content codes (e.g., math, oral language, social studies, etc.), children's engagement with teachers (e.g., scaffolded and didactic approaches and social integration), and activity settings (e.g., whole group, free-choice, etc.). Simultaneous time-sampled measurement of the complexity and reciprocity of teacher-child interactions was conducted using the Adult Involvement Scale (Howes & Stewart, 1987). Child outcomes include measures of language, literacy, math, and social skills. To examine variability in child outcomes (see Table 1) and in children's engagement with academic content and with teachers (see Table 2), descriptive analyses were conducted. The next step in the analysis will be to utilize a person-time approach (Rostgaard, 2008; Rothman & Boice, 1979) to examining variability in infrequent treatment (child engagement in content and quality of teacher-child engagement) occurrences (snapshots). These person-time variables will be entered into Hierarchical Linear Models (HLM; Bryk & Raudenbush, 1992) to test the association of engagement with post-test outcomes, controlling for pretest. We will analyze three-level HLMs to account for nesting of children within classrooms and classrooms within datasets (children at level one, classrooms at level two, and study at level three). Pre-test scores, person-time variables, average engagement in content and the quality of teacher-child engagement are all included as fixed effects. To examine moderation by DLL status or being a Hispanic/Latinx or African-American child, we will create interaction terms in separate models. For the final models, the overall F-test for the main effect adjusting for multiple comparisons via a Benjamini-Hochberg adjustment (Benjamini & Hochberg, 1995) will be conducted and for each of the tests of moderation, and the contrasts and their effect sizes for comparisons of engagement of children from different racial/ethnic and linguistic backgrounds. Findings/Results: Across snapshots, engagement with academic content occurred infrequently, with less than 8% of snapshots documenting children's engagement in math activities and 15% of snapshots capturing engagement with literacy activities. Correlations between child and teacher engagement with child outcomes were in the small range. The size of the correlations were larger with outcomes assessed in Spanish. Next, we will use person-time analyses to examine associations between the occurrence of infrequent child engagement in content, quality of interactions with teachers, and child outcomes. We will also examine variability in engagement, considering the degree to which having sequential engagement (e.g., larger blocks of time) versus infrequent and sporadic content engagement and engagement of varying quality relate to outcomes. Conclusions: Understanding variability in children's experiences within a classroom, and the degree to which that variability relates to children's outcomes is necessary to ensure that instruction is individualized and responsive to the unique needs of individual children. Unique to early care and education, a proportion of daily pre-K schedules are spent in child-directed activities within free-choice, center-based activities, yielding a unique pattern of content exposure and interactions with teachers across individual children within a classroom. Furthermore, additional attention is required to ways in which systemic racism may contribute to the match or mismatch between children's needs and a ubiquitous approach to pre-K quality. The novel analytic approach used in this study to preserve and examine the contribution of individual variability in content and interaction on individual child outcomes will address these important gaps in the extant literature.