This dissertation is developed around two studies created with the goal of describing and quantifying current educators' knowledge and perceptions of reading assessment and subsequent data-based instructional decision making. Unique to the field, a critical component of this study is an emphasis on educators' development of "data literacy" as a knowledge base necessary to the successful education of students in today's classrooms. Study 1 documents the development and validation of a new survey instrument, the "Perceptions, Knowledge, and Interpretation of Reading Assessment" (PKIRA) survey, to assess the perceptions and knowledge of current educators of reading/language arts in grades PK-12. The final version of the PKIRA consists of five sections and/or subscales; (1) demographics, participants' general experience and perceived instructional preparedness section; (2) teacher perception of reading assessment and instruction subscale; (3) teacher reading assessment knowledge and data literacy subscale; (4) teacher knowledge of language structure subscale; and (5) the teacher ability to use data to drive instruction open ended response section. The reliability and validity of this new instrument were analyzed using exploratory factor analysis, item response theory and inter-item correlations. Results indicate the PKIRA is a reliable and valid instrument to measure the knowledge and perceptions of inservice reading teachers. The purpose of Study 2 was to collect data on the knowledge and perceptions from a unique group of inservice reading educators to further validate the PKIRA and determine which aspects of teacher training or experience were associated with reading content knowledge, reading assessment knowledge and data literacy knowledge. Cronbach's alpha, confirmatory factor analysis, item response theory, and ANOVA were used to analyze the data collected. Results provide further support for instrument validation. Results also indicate participants' certification and master's degree status have no statistically significant differences on their mean knowledge score. However, differences in mean knowledge score were found to be associated with teachers' total years teaching and more strongly with, their total years teaching reading. The value of these studies lies in the creation and validation of a reliable new survey instrument that can be used to support the growth and development of data literacy in current educators nationwide. As the PKIRA can provide extensive data on teacher knowledge and perceptions of reading and reading assessment, those who prepare or supervise educators could use the tool to better differentiate and align their instruction to the ever changing needs of the classroom teachers of today. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]