This paper demonstrates evidence-based practice for evaluating the effectiveness of and continuing to improve a first year course on engineering fundamentals and decision-making. In Spring 2015, five instructors in the Department of Engineering at James Madison University taught six sections of an introductory engineering course. The course is a curricular element of the department's first-year experience and is intended to introduce new engineering students to engineering fundamentals, analytical and creative problem solving, systems thinking, engineering and society, sustainable development, and professionalism. As part of course assessment, students completed hand-written concept maps of "engineering decision-making" during the first and last weeks of class. A concept map is a graphical method for identifying and organizing relationships between concepts, related to a central topic, by using a node-link diagram. The instructors wanted to discern if students broadened and deepened their understanding of engineering decision-making over the course of the semester and identify gaps or misconceptions that will need to be addressed during students' subsequent courses and by future runs of the first-year course. The pre and post concept maps were completed during class time in the first and last weeks of the semester. Students were given a brief explanation and examples of how to construct a concept map, using a common set of slides in each section, and then had 10 minutes to complete the maps. The pre and post concept maps were evaluated for structure and connectedness of knowledge using the traditional scoring method which counts and then weights the number of concepts, the number of hierarchies (or branches), the depth of hierarchies, and then number of cross-links connecting different hierarchies. The content of student knowledge was evaluated using thematic analysis to identify trends or gaps in student knowledge compared to the course learning objectives. The results, in terms of both structure and content of student knowledge, suggest that students' conceptualizations of engineering decisionmaking evolved over the course of the semester but that gaps (or low prioritization) between course learning objectives and student conceptualizations may exist. Course instructors are using the results of concept map analysis to continuously improve the course during the Spring 2016 and in future semesters. The instructors would like to help the students make stronger connections between course topics and how each can be incorporated into decision-making for both simple and complex problems. Concept maps are a method that can be employed by other institutions that are assessing a first-year course or have multiple instructors or multiple sections of a first-year course in order to help establish a consistent foundation for future classes. Concept maps are valuable as both a learning tool, helping students make connections within or across classes, and as an assessment tool to inform and monitor the effectiveness ...