This study employed a quantitative research design to examine teacher assessment literacy and its relationship to external and internal factors. The researcher sought to describe the level of assessment literacy that teachers demonstrate when using score report data from computer-adaptive interim assessment and to analyze whether teachers' assessment literacy seems to be affected by: a) the quality of professional development training received; b) teachers' level of self-efficacy; c) teachers' attribution to student effort, that is their perception of the importance of student effort; and d) teachers' attribution to context, specifically their perception of the importance of tests. For this study, a relevant measurement instrument, the Assessment Literacy Skills for Computer Adaptive Tests (ALS-CAT), was designed to provide valid and reliable inferences about assessment literacy skills related to computer-adaptive tests. In addition to the ALS-CAT, the sample of 88 teachers responded to the Multidimensional Multiattributional Causality Scale (MMCS), the Data-Driven Decision-Making Efficacy Anxiety (3DMEA) inventory, and questions quantifying their perception of the quality of professional development experienced. Descriptive and explanatory correlational statistical analysis found no statistically significant relationships between respondents' scores on assessment literacy and respondents' scores on the perceived quality of professional development, perceived self-efficacy, attribution to student effort, or attribution to context. Additional analysis found a relationship between the perceived quality of professional development and perceived self-efficacy. [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/en-US/products/dissertations/individuals.shtml.]