This study uses log file traces to examine differences between high-and low-achieving students' strategic actions in varying learning situations. In addition, this study illustrates, in detail, what strategic and self-regulated learning constitutes in practice. The study investigates the learning patterns that emerge in learning situations that are (a) favourable and (b) challenging. It illustrates, in detail, one high-and one low achieving student's strategic actions in a learning situation that is considered challenging. Elementary school students worked on a science study project for five weeks. During the science project, the students used the gStudy learning environment, which prompted their strategy use and recorded log file traces of their actual strategy use. First, the students were divided into high and low achievers based on their learning gain. Second, gStudy sessions were categorised into either challenging or favourable gStudy sessions based on the students' situation-specific explanations. Third, the learning patterns that emerged in these gStudy sessions were investigated. The results showed that both high-and low-achieving students adopted similar strategies in favourable learning situations. However, when the learning situation was considered challenging, the low-achieving students used surface-level strategies, whereas the high-achieving students used deep strategies for learning. In addition, the case description demonstrated that activating prior knowledge and setting a clear, task-specific goal for studying preceded the high-achieving students' selection of deep strategy in action.