This article reports the findings of an empirical study that investigated whether the source of data--firsthand or secondhand data gained from lab work experiments--has an influence on students' learning outcomes. Results indicate that students' choice of a correct or incorrect hypothesis for a pendulum lab experiment on the influence of the mass of the bob on the time of oscillation does not depend on who the author of the data at hand is: the student themself, a peer, or a teacher. Further, students judge the importance of the data's author as relatively unimportant no matter what data source they have at hand. Thus, it seems fairly unimportant whether students use firsthand or secondhand data when the teaching focus is set on choosing a correct hypothesis in the light of empirical data, as long as students get enough information on how the data were generated and how they are analyzed and interpreted. This result is especially relevant for practitioners, as it shows that it is possible to use secondhand data for the purpose of evaluation and interpretation without significant distortions of epistemic learning processes.