NASA-TLX Based Workload Assessment of Learning Tasks for Primary School Children

Cognitive load (CL) refers to the amount of mental effort and resources required to complete a task or solve a problem. Capacity of the working memory has an impact on children’s education. It is challenging to measure the cognitive load of children required to solve the learning tasks. Assessing the workload of a particular problem or task can help to measure the CL of the children. To measure the workload of different tasks it is also important to develop the tasks suitable for the children. In our study, we have developed various multimedia-based learning tasks for primary school children to measure the workloads of those tasks based on the NASA Task Load Index (NASA-TLX). As our target group is the children of 6 to 8 years, it is difficult for them to provide their feedback as required for NASA-TLX. For the purpose of evaluation, 40 primary school teachers have participated in this study. Instead of six dimension used in NASA-TLX, we initially consider four dimensions which are mental demand, temporal demand, performance and frustration. Based on the feedback of the teachers, we categorize the learning tasks into three different difficulty levels: low, medium and high. We consider both approaches, the weighted and unweighted, for evaluation of the learning tasks. The results show that the weighted and unweighted approaches are highly correlated. Our study for both the approaches indicates that choosing two dimensions, i.e., mental demand and performance, and finally, even one dimension (mental demand or performance), does not significantly change the score of the workload. Further analysis on the results has also revealed that there is no difference between the individual score of different dimensions. The results support educational ergonomics and cognitive workload research applications. This study will help to label the instructional/learning materials of different levels of difficulties for primary school children, where direct feedback technique from the participants is not possible. Such studies will also help to design and develop personalized instructional materials suitable for the children and identify children having some learning disabilities.