In recent years, the XLogoOnline programming platform has gained popularity among novice learners. It integrates the Logo programming language with visual programming, providing a visual interface for learning computing concepts. However, XLogoOnline offers only a limited set of tasks, which are inadequate for learners to master the computing concepts that require sufficient practice. To address this, we introduce XLogoSyn, a novel technique for synthesizing high-quality tasks for varying difficulty levels. Given a reference task, XLogoSyn can generate practice tasks at varying difficulty levels that cater to the varied needs and abilities of different learners. XLogoSyn achieves this by combining symbolic execution and constraint satisfaction techniques. Our expert study demonstrates the effectiveness of XLogoSyn. We have also deployed synthesized practice tasks into XLogoOnline, highlighting the educational benefits of these synthesized practice tasks.

翻译：近年来，XLogoOnline编程平台逐渐受到初学者的青睐。该平台将Logo编程语言与视觉编程相结合，为学习计算概念提供了可视化界面。然而，XLogoOnline仅提供有限数量的任务，不足以帮助学习者通过充分练习掌握计算概念。为解决这一问题，我们提出了XLogoSyn——一种用于合成不同难度级别的高质量任务的新技术。给定一个参考任务，XLogoSyn能够生成不同难度级别的练习任务，以满足不同学习者的多样化需求与能力。XLogoSyn通过结合符号执行与约束满足技术实现这一目标。我们的专家研究证实了XLogoSyn的有效性。我们还将合成的练习任务部署到XLogoOnline中，凸显了这些合成练习任务的教育价值。