From paper to pixel : A LEGO Study of Cognitive Load, Usability, and Flow

Sammanfattning

Digitalization has increasingly replaced physical instruction manuals with smartphone-based systems, yet research suggests that digital formats do not always improve task performance, cognitive processing or user experience. This study investigates how paper-based and smartphone-based instructions influence usability, cognitive load, flow and task performance during a procedural LEGO-building task. Using a mixed-methods and within-subjects design, participants completed the task with both instruction media, including a manipulated notification-interruption condition. Quantitative measures were complemented with semi-structured interviews analyzed through thematic analysis. Results showed that nine out of ten participants preferred paper instructions, which provided a stable spatial overview and required fewer interactions, resulting in lower extraneous cognitive load and fewer attentional disruptions. The digital instructions introduced hyper-segmented steps, notifications and frequent interactions that fragmented attention and reduced the ability to reach flow. Although some app features such as multimodal feedback and enhanced color contrast were appreciated, they did not compensate for the increased cognitive demands. The findings demonstrate that digital instructions do not inherently enhance procedural task performance and highlight the importance of designing digital systems that minimize friction and support attentional continuity.