While block-based programming has successfully eliminated critical syntactic barriers to programming, it remains unclear how effectively it aids in overcoming semantic, logical, and pragmatic programming challenges that hinder computational thinking. These challenges are likely to far outweigh the syntactic ones. With the goal of creating a highly accessible programming tool for young students using mobile devices, we explored the concept of pragmatic prebugging to begin addressing these challenges. By pragmatic prebugging, we refer to proactive debugging tools designed to prevent logical errors. This article introduces RULER.game as a Computational Thinking Tool with built-in pragmatic prebugging, enabling novice programmers to create games through a paradigm we call proxy-based programming. A small study exploring error rates found statistically significant performance improvements of proxy-based programming compared to block-based programming.

Block-based programming languages effectively address syntactic difficulties allowing users to more easily create code. Syntactic code support is no doubt a crucial step in enabling the next generation of programmers. However, in what other ways do these tools support the computational thinking (CT) process? For example, how is CT supported in both the semantic and pragmatic levels? Most users do not just want to write code?they want to create interesting artifacts such as video games, simulations, stories and robots. No doubt that users must code to build these artifacts, but just as important, though often overlooked, is that users must also have an understanding of tool affordances to effectively build these artifacts. The position presented in this paper is that the comprehension of affordances is essential to each stage of the computational thinking process. To that end, we introduce the Hourglass Challenge as a way for students to experience affordances through a programming challenge based on mis-aligned tools and problems. The results from a study, with 54 preservice elementary school teachers, indicate that the affordances of tools can have profound consequences on computational thinking. For instance, the affordances various tools provide can be the difference between creating a simulation versus an animation. But just as hammers are not intrinsically better tools than screwdrivers, the contribution of this position paper is not to compare tools, but to promote efforts that enable learners to develop a better understanding of computational thinking tool affordances as essential mediators between problems and tools.

Recently, Computer Science education in Switzerland reached a critical milestone. In the past two years the School of Education of FHNW, one of Switzerland's largest schools of education, introduced a mandatory Computer Science education module, comprised of a two-course sequence for its students: pre-service primary-level schoolteachers. Due to its design and audience, this mandatory module introduces a variety of unique challenges. The module is taken by a majority of female students (75%), many with no prior experience and/or interest in programming and Computer Science. The module starts with a course focused on learning Computational Thinking, referred to as FW, followed by a course focused on teaching Computational Thinking, referred to as FD. Since 2017, 1000 pre-service primary-level teachers have been trained in Computer Science education through this module. This curricula initiative computes the effect sizes from teaching two complete iterations of the "FW then FD" design. It is based on attitude assessment data collected at four points: Pre-FW, Post-FW, Pre-FD, Post-FD, during the first two years of this mandatory module. Our research indicates that, by course's end, pre-service teachers are mostly confident in their ability to program and think computationally.

A promising approach to make K-12 Computer Science education more systemic could arise from a strategy focusing mostly on pre-service teachers educated through mandatory courses instead of self-selected in-service teachers. When employing mandatory courses, schools of education can reach all future teachers, but what are potential consequences resulting from this demographic shift? Pre-service teachers may not expect to acquire programming skills and may not be convinced of the relevance of Computer Science. In 2017, one of the first mandatory Computer Science education courses for pre-service K-12 teachers was introduced at the School of Education of northwestern Switzerland (PH FHNW). The mandatory nature of the course was possible because of the introduction of Computer Science as a subject in a new national curriculum. The course, based on Scalable Game Design, was taken by over 600, mostly female (75%), pre-service elementary school teachers. This paper explores the characteristics of this new audience and investigates the consequences of mandatory pre-service teacher Computer Science education. While our research shows that the course was successful, with regards to improving the students' skills, it reveals significant gender effects concerning attitudes towards Computer Science and self-efficacy.

The creation of computer science tutorials is becoming critically important as hundreds of millions of students each year get their first CS experience through self-directed online activities. Creating a "cliffhanger" activity, with high engagement during and motivation to continue learning post activity, is a balancing act. If tutorials provide too much detailed information, users may be able to follow instructions but can feel overwhelmed or bored. On the other hand, tutorials that do not sufficiently explain crucial steps risk frustrating users who might drop out of the activity. Zones of Proximal Flow (ZPF) tutorials are simple to create and provide a navigation structure of differentiated instruction allowing users to choose appropriate detail based on their self-assessed state of flow, from bored to anxious. Using Retention of Flow analysis, two Hour of Code game design tutorials were analyzed: a sophisticated online tutorial for the creation of Frogger, and a simple ZPF tutorial for the creation of Pac-Man. One hope was that the simple ZPF Pac-Man tutorial would not do much worse than the sophisticated Frogger tutorial, but surprisingly the ZPF Pac-Man tutorial significantly outperformed the Frogger tutorial in terms of student retention. The Pac-Man tutorial also displayed a high student motivation to continue programming past the end of differentiated instruction.

Broadening participation in computer science necessitates balancing motivational and educational concerns. Without fully understanding potential trade-offs, Hour of Code-like tutorials may actually backfire by initially attracting students to participate, but gradually reinforcing the notion that programming is hard and boring. Previously, we analyzed and compared two Hour of Code tutorials: a tutorial that walks students through the creation and programming of a 3D-Frogger game, including the drawing of their own 3D characters, to a programming puzzle where students solve discrete coding challenges. Using an analysis based on retention, the comparison indicated higher levels of perseverance in the game creation activity. However, does the ability to draw characters really motivate students to program? Conflicting theories of positive and negative effects of drawing onto perseverance include that drawing might increase levels of participant ownership or that drawing may just be wasting time better spent programming, especially in the time constrained Hour of Code context. To gain insight, this study uses draw times of over 8,000 projects from a game creation Hour of Code activity in 2016. Initial results indicate that higher average draw time per character corresponds to increased program lengths and students with the highest average draw times per character continued to program beyond the end of the activity

Online CS Ed Week and Hour of Code activities attempt to motivate hundreds of millions of student participants across the world in computer science each year. A key goal of these endeavors is long-term student engagement. However, if the activity experience is bad, it could have effects adverse to the stated goal. Thus, it is imperative upon designers to actively improve the online activity ensuring the maximum numbers of students are retained throughout the exercise. We present a simple proof of concept method outlining a means for Computer Science Education Week and Hour of Code online activities to identify and improve hazardous points wherein students tend to drop out. This is achieved by finding so called flow stoppers in activity retention that diverge from an ideal theoretical Markov chain model, and scaffolding the activity at that point to better support participants. Initial data presented indicates that even minor changes can have a significant effect on keeping a greater number of students engaged.

Computer Science Education Week activities, featuring online? programming tools embedded with tutorials, report large participation numbers. However, to truly broaden participation, activities need to be made accessible in international contexts. In 2014, Tecnológico de Monterrey and Instituto de Innovación y Transferencia de Tecnología de Nuevo León, modified the Scalable Game Design CS Ed Week activity to include a Mexican feasibility pilot study. The goal of the pilot was to broaden participation in Computer Science in Mexico by creating interest and demand in further activities, including launching of 2015 Mexico CS Ed Week. This paper reviews the initial results of this 2014 pilot, including the discussion of the unique challenges faced in this context, and examines efforts to make this activity more accessible and successful. In addition to pilot data highlighting future activity improvements, initial retention results show that despite challenges, Mexican students were able to effectively use the modified activity to create games on par with U.S. students.

High profile computer science education events such as the Hour of Code can reach millions of students but without proper evaluation it is not clear what motivational and educational consequences the participation has. If, for instance, participants' levels of motivation towards the end of an hour long activity are significantly fading, then their perception of programming to be "hard and boring" may actually get reinforced. By simply measuring how far participants progressed with their projects we have been able to collect retention data from thousands of participants in a way that allows us to interpret these data in terms of not only cognitive but also technical and practical activity challenges. Inflection points overlaying a negative exponential retention distribution serve as indicators of these challenges with potential impact on Flow. Retention of Flow is an evaluation approach to analyze computer science education activities, including interactive tutorials and online programming environments, with respect to cognitive as well as affective challenges.

Computational Thinking is an essential skill for all students in the 21stCentury. A fundamental question is how can we create computer affordances to empower novice teachers and students, in a variety of STEM and art disciplines, to think computationally while avoiding difficult overhead emerging from traditional coding? Over the last 20 years we have iteratively developed tools that aim to support computational thinking. As these tools evolved a philosophy emerged to support Computational Thinking by joining human abilities with computer affordances. Chief among these findings is that supporting Computational Thinking is much more than making coding accessible. Computational Thinking Tools aim to minimize coding overhead by supporting users through three fundamental stages of the Computational Thinking development cycle: problem formulation, solution expression, and solution execution/evaluation.

Teachers are increasingly integrating game design and simulation creation projects as part of their classroom curricula. These projects have many benefits including motivating students in STEM activities and exposing students to computational thinking - a key part of upcoming science standards. However, barriers still exist to project-based computer science in a lab environment. One major issue is that, as students are creating their projects, it is extremely difficult for teachers to know how every student is progressing through a given activity and how to keep every student engaged. This paper introduces a Cyberlearning system entitled REACT (Real-Time Evaluation and Assessment of Computational Thinking) that is an initial step towards giving teachers quickly discernible real-time data corresponding to each student project. REACT provides teachers with a sortable dashboard, consisting of data from each student, that shows the characters students created and used to populate their game or simulation world as well as the semantic meaning behind what students have programmed. A feasibility test with four middle school classrooms shows that REACT helps teachers formatively assess students and provide targeted instruction to struggling individuals. Furthermore, teachers showed excitement at the summative and student self-assessment capabilities of REACT, and every teacher independently stated they would use the REACT system in subsequent end-user programming units.

An educated citizenry that participates in and contributes to science technology engineering and mathematics innovation in the 21st century will require broad literacy and skills in computer science (CS). School systems will need to give increased attention to opportunities for students to engage in computational thinking and ways to promote a deeper understanding of how technologies and software are used as design tools. However, K-12 students in the United States are facing a broken pipeline for CS education. In response to this problem, we have developed the Scalable Game Design curriculum based on a strategy to integrate CS education into the regular school curriculum. This strategy includes opportunities for students to design and program games and science technology engineering and mathematics simulations. An approach called Computational Thinking Pattern Analysis has been developed to measure and correlate computational thinking skills relevant to game design and simulations. Results from a study with more than 10,000 students demonstrate rapid adoption of this curriculum by teachers from multiple disciplines, high student motivation, high levels of participation by women, and interest regardless of demographic background.

End-user game design affords teachers a unique opportunity to integrate computational thinking concepts into their classrooms. However, it is not always apparent in game and simulation projects what computational thinking-related skills students have acquired. Computational Thinking Pattern Analysis (CTPA) enables teachers to visualize which of nine specific skills students have mastered in game design that can then be used to create simulations. CTPA has the potential to automatically recognize and calculate student computational thinking skills, as well as to map students' computational thinking skill progression, as they proceed through the curriculum. The current research furthers knowledge of CTPA by exploring its validity based on how its performance correlates to human grading of student games. Initial data from this validation study indicates that CTPA correlates well with human grading and that it can even be used to predict students' future achievement levels given their current skill progression, making CTPA a potentially invaluable computational thinking evaluation tool for teachers.

Future school science standards, such as the Next Generation Science Standards (NGSS), emphasize the integration of simulation and modeling activities in the classroom environment. The extremes of these activities have two vastly different implementations. On one hand, a teacher can have students experiment on a pre-made simulation associated with the material. On the other hand, students can use, for example, an end-user programming tool to create the simulation from scratch. This allows students to not only experiment on, but also, to model the real world phenomenon being studied- a key component of computational thinking. However, the greater amount of time necessary for student authoring of simulations can make such an approach infeasible in the classroom environment. This paper presents a spectrum of strategies for integrating simulations into class- rooms emphasizing our research at the Scalable Game Design Lab, University of Colorado Boulder as well as research from other entities. Starting at consuming simulations and adding more user interaction and authoring elements begins to provide a gentle slope from consumption towards simulation creation. Results indicate that many of these strategies are quite effective.

This paper suggests a Cyberlearning tool based on a highly innovative assessment methodology that helps teachers with computer science education. Currently, there is a strong push to integrate aspects of programming and coding into the classroom environment. However, few if any tools exist that enable real-time formative assessment of in-class programming tasks. The proposed REACT (Real Time Evaluation and Assessment of Computational Thinking) system is a first step toward allowing teachers to see which high-level concepts students have mastered and which ones they are struggling with as students code in real time. REACT supports and facilitates the teaching of 21st century computing skills such as computational thinking [1] in the classroom environment.

This paper presents a novel pedagogical framework, entitled the Zones of Proximal Flow, which integrates Vygotsky's Zone of Proximal Development theory with Csikszentmihalyi's ideas about Flow. Flow focuses on the individual-- an individual is in Flow when challenges are balanced with skills. The Zone of Proximal Development, on the other hand, brings in a social learning aspect focusing on a student's ability to learn concepts with external support. From our research experiences bringing game and simulation design into middle school classrooms, we attempt to provide students with appropriate challenges using a project-first based approach that aims to keep students in Flow. The project-first approach employs inquiry based scaffolding to guide students, with appropriate support by their teachers, through Vygotsky's Zone of Proximal Development, back in to Csikszentmihalyi's state of Flow for an ideal learning experience. We call this space the Zones of Proximal Flow. Data indicate that the Zones of Proximal Flow approach works, keeping classrooms engaged in the act of game design and enabling students to advance to more complex program creations.

Computational thinking aims to outline fundamental skills from computer science that everyone should learn. These skills include problem formulation, logically organizing data, automating solutions through algorithmic thinking, and representing data through abstraction. One aim of the NSF is to integrate these and other computational thinking concepts into the classroom. This paper introduces a tool called the Simulation Creation Toolkit wherein users apply high-level agent interactions called Computational Thinking Patterns (CTPs) to create simulations. Programming at the Computational Thinking Pattern level allows users to directly create agent interactions in a simulation by employing generic icons acting out a scientific phenomenon they are trying to represent. The Simulation Creation Toolkit aims to preserve the computational thinking benefits of simulation creation while enabling higher-level implementation of agent behaviors. Initial study data collected from sixth grade students with no prior programming experience indicates that students can work the mechanics necessary to create simulations in the classroom environment using the Simulation Creation Toolkit.

End-user game design tools are effective in motivating and exposing students with no prior programming experience to computer science. However, while there is good evidence that these environments are effective motivators, the question remains what do students actually learn? For our purposes, using AgentSheets, we would like to know if students can apply the knowledge obtained from programming games to creating science simulations. Specifically, we want to better understand if students are able to recognize Computational Thinking Patterns (CTP) from their game programming experience. Computational Thinking Patterns are abstract programming patterns that enable agent interactions not only in games but also in science simulations. Students and teachers who participated in a game design summer institute were administered a Computational Thinking Pattern Quiz (CTP Quiz). This quiz tested the participants' ability to recognize and understand patterns in a context removed from game programming. We found that participants, for the most part, were able to understand and recognize the patterns in a variety of contexts

A variety of approaches exist to teach computer science concepts to students from K-12 to graduate school. One such approach involves using the mass appeal of game design and creation to introduce students to programming and computational thinking. Specifically, Scalable Game Design enables students with varying levels of expertise to learn important concepts relative to their experience. This paper presents our observations using Scalable Game Design over multiple years to teach middle school students, college level students, graduate students, and even middle school teachers fundamental to complex computer science and education concepts. Results indicate that Scalable Game Design appeals broadly to students, regardless of background, and is a powerful teaching tool in getting students of all ages exposed and interested in computer science. Furthermore, it is observed that many student projects exhibit transfer enabling their games to explain complex ideas, from all disciplines, to the general public.

Cyberlearning infrastructures are increasingly being integrated into physical classrooms and are often used by online classes as an outright replacement for the physical classroom. In Spring 2009, The Educational Game Design Class, taught at the University of Colorado Boulder, employed a cyberlearning infrastructure enabling students to run and even download classmate assignment submissions before the homework deadline. This cyberlearning infrastructure, called the Scalable Game Design Arcade, also allowed students to give feedback on other students' assignments. Analysis of data from the Scalable Game Design Arcade indicates that students used the online infrastructure to play and appraise fellow students' games. Interestingly however, data suggests that most students preferred to give feedback verbally in-person during class; data also indicates that in-class feedback was the most effective in terms of getting students to improve and resubmit their assignments.

Visual programming languages can be used to make computer science more accessible to a broad range of students. The evaluative focus of current research in the area of visual languages for educational purposes primarily aims to better understand motivational benefits as compared to traditional programming languages. Often these visual languages claim to teach students computational thinking concepts; however, although the evaluations show that students may exhibit more enthusiasm, it is not always clear what computational thinking concepts students have actually learned. In this paper we attempt to develop a visual semantic evaluation tool for student-created games and simulations that goes towards depicting the computational thinking concepts implemented by the students. Through semantically analyzing a given student's created projects over time, this visual evaluation tool, called the Computational Thinking Pattern (CTP) graph, can possibly indicate the existence of computational thinking transfer from games to science simulations.