Abstract This paper establishes the decidability of the well-specification problem for population protocols, a model of distributed computation by anonymous, finite-state agents. A protocol is well-specified if all fair executions from any initial configuration stabilize to... This paper establishes the decidability of the well-specification problem for population protocols, a model of distributed computation by anonymous, finite-state agents. A protocol is well-specified if all fair executions from any initial configuration stabilize to the same consensus value. The authors prove decidability by characterizing well-specification through the existence of a "witness": a tuple of four Presburgerdefinable, inductive sets of configurations and a bounded language that together guarantee convergence. This characterization leverages deep results from Petri net theory, including the Presburger-definability of mutual reachability and separators for unreachable markings. The same techniques also show decidability for the correctness problem (verifying if a protocol computes a given Presburger predicate) and yield a new decidability result for the home space problem in Petri nets under specific finiteness conditions. Read More Read Less

Abstract This paper presents an experience report on transitioning a large CS1 course at Reykjavik University from face-to-face to online instruction during the COVID-19 pandemic. The course, already based on a Flipped Classroom (FC) and Team... This paper presents an experience report on transitioning a large CS1 course at Reykjavik University from face-to-face to online instruction during the COVID-19 pandemic. The course, already based on a Flipped Classroom (FC) and Team Based Learning (TBL) model, was moved to a synchronous online format using Zoom, Mimir, Piazza, and Canvas. Students prepared before class by watching videos and reading materials, then engaged in live sessions with quizzes and team programming tasks in Zoom breakout rooms. Surveys showed that student satisfaction remained high and comparable to the previous in-person year, with 74.1% of students pleased with the course. Exam performance showed no significant difference between 2019 and 2020, indicating that online delivery did not negatively impact learning outcomes. While some challenges were noted such as reduced peer interaction and lower Piazza usage the study concludes that FC and TBL can be effectively implemented online. The authors suggest that future flexibility be allowed, enabling students to choose between online and in person formats. Read More Read Less

Abstract The paper presents a case study applying the TechTeach methodology—a student-centered, gamified, blended-learning approach—in a fully online programming course at the University of Minho during the 2020–2021 academic year, necessitated by the COVID-19 pandemic. The... The paper presents a case study applying the TechTeach methodology—a student-centered, gamified, blended-learning approach—in a fully online programming course at the University of Minho during the 2020–2021 academic year, necessitated by the COVID-19 pandemic. The study involved 168 students and aimed to assess whether TechTeach could be effectively adapted to 100% online instruction. The approach integrated project-based learning, flipped classrooms, gamification, and soft skills development, supported by digital tools such as Zoom, ioEduc, ioChat, Kahoot!, and HackerRank. Results showed high student engagement, with over 220,000 page views, 15,000 chat messages, and 11,000 file downloads. Over 95% of students rated the course average or above compared to others, and 85% approved of the gamification system. Despite challenges such as unequal access to technology, the study concluded that TechTeach is effective in online environments, although it requires significant effort from instructors. The findings support its potential for fostering motivation, innovation, and entrepreneurship in distance education. Read More Read Less