In this study, we conducted semi-structured interviews with 21 IIR researchers to investigate their data reuse practices. This study aims to expand upon current findings by exploring IIR researchers' information-obtaining behaviors regarding data reuse. We identified the information about shared data characteristics that IIR researchers need when evaluating data reusability, as well as the sources they typically consult to obtain this information. We consider this work to be an initial step toward revealing IIR researchers' data reuse practices and identifying what the community needs to do to promote data reuse. We hope that this study, as well as future research, will inspire more individuals to contribute to ongoing efforts aimed at designing standards, infrastructures, and policies, as well as fostering a sustainable culture of data sharing and reuse in this field.