Clinical diagnosis of genetic disorders requires sensemaking to connect patients' symptoms at the macroscopic level with the abnormalities at the microscopic level. This involves making relevant observations regarding the patients and their symptoms, analyzing different data sources to find connections across the data points, and, representing the information in a meaningful and coherent manner to justify the rationale behind the diagnostic decisions. Undergraduate students lack these skills pertaining to sensemaking due to fewer practice opportunities, no exposure to authentic real-life problems, and more focus on grade-oriented rote learning. Students, when encountered with such complex tasks, try to gain the competence required to accomplish the task, which leads to an increase in their self-efficacy. Karyotype, a technology-enhanced learning environment designed for sensemaking poses the complex task of clinical diagnosis of genetic disorders caused due to chromosomal abnormalities. We conducted an exploratory study with 67 bioscience majors students. We analyzed students' perceived self-efficacy through a questionnaire administered pre and post their interaction with Karyotype. The results suggest that working on Karyotype learning activities enhances students' self-efficacy related to sensemaking tasks.