This report summarizes the findings of a literature review conducted as part of the Assessing Early Childhood Teachers' Use of Child Progress Monitoring to Individualize Teaching Practices project funded by the Office of Planning, Research and Evaluation within the Administration for Children and Families at the U.S. Department of Health and Human Services. The purposes of the project are to develop a conceptual model of early childhood teachers' use of ongoing child assessment to individualize instruction and to create a measure that assesses teacher implementation of that process; this measure will be called the Tool for Tailored Teaching (T3; see Volume I of this report). The literature review summarized in this volume was designed to (1) identify the critical areas to be addressed by a measure of teachers' use of ongoing assessment for individualization and (2) find examples of how others have measured teachers' use of ongoing assessment for individualization. Overall, limited rigorous evidence is available about the areas critical for the successful implementation of ongoing assessment to individualize instruction. The literature does not provide guidance on how to determine whether these activities are well-implemented, nor does it describe the factors that influence teachers' abilities to implement the activities well. Although the literature does present a picture of the activities we are likely to see when teachers use ongoing child assessment data for individualization, that picture is incomplete and largely limited to the early elementary level in the domain of language and literacy. Limited research is available about some of the activities involved in this ongoing assessment process, and most of the studies focused on one or two of the activities, leaving few examples that focus on the process in its entirety. Few causal studies have examined the types of ongoing support for teachers, particularly teachers working with children from birth to age 5, that may lead to improvements in both teacher's use of ongoing assessment data to individualize instruction and, ultimately, child outcomes. Of the 173 studies reviewed, only 21 attempted to measure teachers' implementation of ongoing assessment and the individualization process. Only some of those studies provided detailed information about the measures used to assess implementation, and more than half were conducted at the early elementary level. The literature does provide some examples of measures that assess how well teachers implement ongoing assessment tools and whether teachers make any instructional modifications in response to ongoing assessment data. However, the literature provides few examples of measures that assess two important areas: (1) how teachers make instructional decisions based on these data and (2) the knowledge and skills necessary for teachers to successfully implement ongoing assessment for individualization, especially with infants, toddlers, and preschoolers and in home visiting settings. Across all dimensions of implementation, we lack evidence linking assessments of teacher implementation of ongoing assessment to child outcomes. This review points to a number of gaps in the knowledge base about ongoing assessment for individualization that future research should address. The T3 measure will build on the current literature and extend beyond it by capturing an array of the activities involved in the process and assessing implementation across a range of ongoing assessment tools. Ultimately, research will be needed to determine whether high-quality implementation of ongoing assessment to inform individualization as assessed with the T3 is linked to improved instructional practices and, ultimately, positive child outcomes. (author abstract)