Introducing computational thinking to second and third graders. Programming whole paths outperforms step-by-step navigation in maze tasks

• Early CT education using LEGO® and Scratch improves problem-solving in young learners. • Programming whole paths fosters deeper engagement compared to verbal step-by-step tasks. • Algorithmic thinking through sequence length positively impacts computational learning. • Age-appropriate digital tools effectively teach basic directions and sequences to children. Computational Thinking (CT) has been considered one of the 21st century skills that already primary school students should develop. In this study we compared different methods for guiding a real object through a training maze task to teach N = 70 second and third graders basic computational thinking concepts, i.e., basic directions and sequences. Students in the experimental condition used LEGO® Education SPIKE™ Essential-Set and Scratch-based icon blocks software to navigate a maze, while the control group used regular LEGO®-Sets and verbal commands. Results supported our hypotheses: students in the experimental condition outperformed those in the control condition, produced longer sequences and more sequence commands to direct their object through the maze, and a positive relationship was observed between sequence length and posttest performance. Furthermore, mediation analysis revealed that the effect of the intervention on posttest achievement was influenced by the use of longer sequences. Our study underpins that Scratch-based block programming combined with robot-like real-world devices is a promising way to utilize CT in (early) primary education—and deepens our knowledge about how students engage in relevant learning activities.