At SIGCSE 2022 we reported on a grant funded CSforAll project to develop comprehensive and sustained college-high school partnerships focused on building computer science (CS) teacher capacity and broadening participation in high school CS classrooms. The partnerships involve a wide range of districts including high-needs and small rural ones. In this paper we first provide an update on this distinctive and successful project. Grant funding ended in 2022, however the project continues to grow and evolve. Led by faculty at a small liberal arts college, some of the results are stunning and demonstrate the impact a small college can have. For example, in the last three years the number of partner school districts has increased from 23 to 54. The teacher retention rate is 95%, with the most veteran teachers belonging to the partnership for almost ten years. This update includes two additional years of data on student experiences in their CS classes. Second, we provide suggestions and encouragement for replicating this work. The project provides a model that can be used by other colleges and universities for building long-term partnerships with schools to improve CS education. Important components of this model include summer and school year professional development, curriculum and support for four CS courses, a dual-enrollment program, teacher CS certification pathways, and a professional learning community. We offer suggestions and identify opportunities and challenges for those interested in developing a similar program.

We present a new high school level computer science (CS) curriculum that is a key component of a comprehensive college/high school partnerships program supporting secondary CS education in New York State. The year-long curriculum offers a broad introduction to CS and is designed using best practices for promoting diversity, equity, and inclusion. It was collaboratively designed and implemented by a team of college CS faculty and high school CS teachers participating in a research-practice partnership. This year (AY2023-2024) the curriculum is being taught in 27 school districts representing high-needs, rural, and suburban communities. Preliminary analysis of student data is included.

Previous research on belonging in computer science offers insights into the role that stereotypes play in reducing females' sense of belonging or fit in computer science (CS), which has been associated with their significant underrepresentation in the field. Drawing upon mixed methods (surveys and interviews), this study explores the quantitative variables associated with a sense of belonging for females in high school CS courses and provides qualitative insights from students to help explain why these factors matter. Pre/post survey analysis indicates that the courses are contributing to reducing pre-course gender gaps in students' perceived efficacy and belonging in a CS classroom. The surveys also suggest that females were more engaged and developed stronger relationships with teachers. And yet, females' commitments to continuing with CS had no statistically significant changes. Student interviews provide important context regarding the quantitative findings and describe how positive relationships with a female teacher, collaborative work and inclusive teaching practices played key roles in promoting a classroom sense of belonging for females. Overall, these results suggest that an academically engaging and socioemotionally supportive experience in a computer science course can reduce gender gaps and foster females' sense of belonging in the classroom even if they retain some reservations over their long-term fit in the field. The findings contribute to a more nuanced understanding of the factors that promote equitable experiences for females in CS and the relationship between classroom level belonging and long-term fit in computer science.

A polycube graph is a polyhedron composed of cubes glued together along whole faces, whose surface is a 2-manifold. A polycube graph is 3-separated if no two boxes of degree 3 or higher are adjacent, and no grid edge is entirely surrounded by boxes (i.e., there is no cycle of length 4). We show that every 3-separated polycube graph can be unfolded with a 7×7 refinement of the grid faces. This result extends the class of well-separated polycube graphs known to have an unfolding by allowing boxes of degree 2 to be adjacent to each other and to higher degree boxes.

Expanding access to and engaging diverse groups of students in high school computer science (CS) classes depends on qualified CS teachers. In this paper, we describe how faculty at our liberal arts college built CS teacher capacity at over 20 school districts through comprehensive college/high school partnerships. The majority of these districts serve rural or high-needs students, groups underrepresented in CS classrooms. The program works primarily with in-service teachers from other disciplines, helping them develop the expertise to teach CS. It is comprehensive in that it includes curricula and professional development for a high school level CS course and a dual-enrollment college level CS course, pathways to CS certification, community events, and opportunities for teacher leadership and collaboration. These modes of engagement are structured so that novice and veteran teachers and college faculty have opportunities to interact in different capacities over several years to create a robust professional learning community. Initial survey results show increasing levels of teacher confidence and sense of belonging, and increasing student confidence in their CS abilities.

We present nonoverlapping general unfoldings of two infinite families of nonconvex polyhedra, or more specifically, zero-volume polyhedra formed by double-covering an n -pointed star polygon whose triangular points have base angle α . Specifically, we construct general unfoldings when n ∈ { 3 , 4 , 5 , 6 , 8 , 9 , 10 , 12 } (no matter the value of α ), and we construct general unfoldings when α < 60 ∘ ( 1 + 1 / n ) (i.e., when the points are shorter than equilateral, no matter the value of n , or slightly larger than equilateral, especially when n is small). Whether all doubly covered star polygons, or more broadly arbitrary nonconvex polyhedra, have general unfoldings remains open.

We show that every polycube tree can be unfolded with a 4×4 refinement of the grid faces. This is the first constant refinement unfolding result for polycube trees that are not required to be well-separated.

We present the first universal reconfiguration algorithm for transforming a modular robot between any two facet-connected square-grid configurations using pivot moves. More precisely, we show that five extra "helper" modules ("musketeers") suffice to reconfigure the remaining n modules between any two given configurations. Our algorithm uses O(n^2) pivot moves, which is worst-case optimal. Previous reconfiguration algorithms either require less restrictive "sliding" moves, do not preserve facet-connectivity, or for the setting we consider, could only handle a small subset of configurations defined by a local forbidden pattern. Configurations with the forbidden pattern do have disconnected reconfiguration graphs (discrete configuration spaces), and indeed we show that they can have an exponential number of connected components. But forbidding the local pattern throughout the configuration is far from necessary, as we show that just a constant number of added modules (placed to be freely reconfigurable) suffice for universal reconfigurability. We also classify three different models of natural pivot moves that preserve facet-connectivity, and show separations between these models.

In this workshop, we will describe the numerous processes and tasks involved in successfully hosting a high school programming contest. We will describe the mechanics of running the contest using PC^2, within the logistics of a college campus environment. We will talk about the logistics necessary to support the number of high schools and teams (currently we involve 15+ high schools and over 60 4-person teams). Finally, we will describe our local chapter of CSTA, which strengthens bonds and connections between ourselves and the school's coaches and advisors.

Recruiting and retaining STEM majors has been an ongoing challenge for colleges and universities. This research paper describes two initiatives to recruit and retain Computer Science (CS) majors that were implemented at Siena College starting in the fall of 2014. Both initiatives are directed at rising sophomores who have completed the first year CS sequence as an early strategy to encourage them to declare and complete the CS major. The first initiative is an early internship program directed at providing students an opportunity to apply those technical skills, extend their skill set, and introduce them to meaningful real-world projects between their freshman and sophomore years. The second initiative is a lab/classroom assistant program where sophomore or older students provide mentoring during lecture and lab sessions for the introductory CS courses. The paper provides preliminary findings, lessons learned, and directions for the future.

In this paper, we describe our experiences with a new model for in-service computer science (CS) professional development that embeds college/university faculty into local high school classrooms partnered with a high school teacher. The high schools we have worked with had not previously offered any rigorous CS courses, and the teachers had little or no CS background. Our goal is to provide the development necessary for the high school teachers to be able to independently teach an engaging and rigorous college level CS course. We have leveraged the local nature of our program to ensure an on-going partnership between the high schools and the college/university lasting beyond the structured professional development program. Here we describe our program, the teachers and schools we have worked with, our community building efforts, and our next steps. We also present outcomes and data from our initial evaluations.

Computer Science (CS) is not taught in enough high schools thus many students arrive at college or university knowing little about it and often do not consider taking a CS course during their first year. At the same time, we encounter many college or university juniors and seniors who, while taking their first CS course, discover an aptitude and interest, at which point it is too late. We describe an innovative one-week residential summer program designed to educate non-computer science majors, before their second year of college or university, about the field's many areas and long-term prospects. The program has succeeded at encouraging undecided students to major or minor in CS and thus somewhat ameliorates the lack of CS in K-12 education and furthers the conference goal of "CS For All".

We show that every orthogonal polyhedron of genus at most 2 can be unfolded without overlap while using only a linear number of orthogonal cuts (parallel to the polyhedron edges). This is the first result on unfolding general orthogonal polyhedra beyond genus-0. Our unfolding algorithm relies on the existence of at most 2 special leaves in what we call the "unfolding tree" (which ties back to the genus), so unfolding polyhedra of genus 3 and beyond requires new techniques.

We describe a new methods of teaching computer science (CS) course tailored for mathematics education majors but also applicable to others interested in teaching CS. Goals of the course are enhancing their ability and confidence in developing and offering CS courses at high schools and starting CS courses at high schools that do not offer them. The course involves a combination of reading, programming, lesson/unit plan development, code reviews, and discussion of the various paradigms for introducing CS at the secondary level. Results indicate the course enhances the students' confidence, ability, and preparation for teaching CS in high schools.

We introduce the study of forcing sets in mathematical origami. The origami material folds flat along straight line segments called creases, each of which is assigned a folding direction of mountain or valley. A subset F of creases is forcing if the global folding mountain/valley assignment can be deduced from its restriction to F. In this paper we focus on one particular class of foldable patterns called Miura-ori, which divide the plane into congruent parallelograms using horizontal lines and zigzag vertical lines. We develop efficient algorithms for constructing a minimum forcing set of a Miura-ori map, and for deciding whether a given set of creases is forcing or not. We also provide tight bounds on the size of a forcing set, establishing that the standard mountain-valley assignment for the Miura-ori is the one that requires the most creases in its forcing sets. Additionally, given a partial mountain/valley assignment to a subset of creases of a Miura-ori map, we determine whether the assignment domain can be extended to a locally flat-foldable pattern on all the creases. At the heart of our results is a novel correspondence between flat-foldable Miura-ori maps and 3-colorings of grid graphs.

We show that every orthogonal polyhedron homeomorphic to a sphere can be unfolded without overlap while using only polynomially many (orthogonal) cuts. By contrast, the best previous such result used exponentially many cuts. More precisely, given an orthogonal polyhedron with n vertices, the algorithm cuts the polyhedron only where it is met by the grid of coordinate planes passing through the vertices, together with Θ(n 2) additional coordinate planes between every two such grid planes.

Modular robots consist of many identical units (or atoms) that can attach together and perform local motions. By combining such motions, one can achieve a reconfiguration of the global shape of a robot. The term modular comes from the idea of grouping together a fixed number of atoms into a metamodule, which behaves as a larger individual component. Recently, a fair amount of research has focused on algorithms for universal reconfiguration using Crystalline and Telecube metamodules, which use expanding/contracting cubical atoms.From an algorithmic perspective, this work has achieved some of the best asymptotic reconfiguration times under a variety of different physical models. In this paper we show that these results extend to other types of modular robots, thus establishing improved upper bounds on their reconfiguration times. We describe a generic class of modular robots, and we prove that any robot meeting the generic class requirements can simulate the operation of a Crystalline atom by forming a six-arm structure. Previous reconfiguration bounds thus transfer automatically by substituting the six-arm structures for the Crystalline atoms. We also discuss four prototyped robots that satisfy the generic class requirements: M-TRAN, SuperBot, Molecube, and RoomBot.

Given a set S of points in the plane representing wireless devices, each point equipped with a directional antenna of radius r and aperture angle α⩾180°, our goal is to find orientations and a minimum r for these antennas such that the induced communication graph is strongly connected. We show that r=3 if α∈[180°,240°), r=2 if α∈[240°,270°), r=2sin(36°) if α∈[270°,288°), and r=1 if α⩾288° suffices to establish strong connectivity, assuming that the longest edge in the Euclidean minimum spanning tree of S is 1. These results are worst-case optimal and match the lower bounds presented in [I. Caragiannis, C. Kaklamanis, E. Kranakis, D. Krizanc, A. Wiese, Communication in wireless networks with directional antennae, in: Proc. of the 20th Symp. on Parallelism in Algorithms and Architectures, 2008, pp. 344–351]. In contrast, r=2 is sometimes necessary when α<180°.