Computational thinking (CT) is recognized as an essential and universally applicable skill for all disciplines (Wing, 2006; Bundy, 2007). Proponents of CT acknowledge that it is integral to fostering 21st century skills such as problem-solving and higher-order thinking (Barr & Stephenson, 2011; Wing, 2006). Educational robotics activities have been shown to foster these skills, yet little attention has been given to how to assess students' use of CT in the context of such activities, particularly within K-12 classrooms (Fu et al., 2020; Chevalier et al., 2020; Chen et al., 2017; Witherspoon et al. 2017). As an alternative to physical educational robotics, virtual educational robotics is a less costly way to bring CT-building activities into K-12 classrooms (Tselegkaridis & Sapounidis 2021; Eguchi 2012; Tellez 2017). This dissertation study investigates how participation in virtual educational robotics activities elicits middle school students' use of computational thinking. The study also examines whether and how middle school students' written and verbal reflections on virtual robotics artifacts captures computational thinking (i.e., students articulate their use of computational thinking). The purpose of this qualitative case study is to develop a deeper understanding of how middle students' employ and communicate their use of computational thinking, regardless of whether or not they know the jargon associated with its concepts and practices. The study seeks to answer the questions: 1) How do middle school students' virtual educational robotics artifacts exhibit computational thinking? 2) How do middle school students articulate their use of computational thinking in written reflections on their virtual educational robotics artifacts? and 3) To what extent do virtual educational robotics artifacts facilitate students' articulation of computational thinking in their verbal reflections? Using the theories of constructionism and reflection-in-action as theoretical lenses, the study provides an analysis of middle school students' computational artifacts, written reflections, and verbal reflections via semi-structured interviews. This analysis adopts a conceptual framework for computational thinking adapted from that of Brennan and Resnick (2012) which includes the key dimensions of concepts and practices important to computational thinking. Results revealed that middle school students' use of computational thinking concepts was more evident in their computational artifacts than either their written reflections or verbal reflections given during their interviews. However, written and verbal reflections revealed that students were engaging in computational practices even when their language did not use the jargon associated with computational thinking. Overall, the study confirms and builds upon scholarship asserting that reflection is a key component of computational thinking (Papert, 1991; Ackermann, 1996) and highlights the importance of an expert practitioner in modeling such reflection (Schon, 1987). [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]