In this study we adopt a mixed method approach to research pre-service elementary teachers' self-efficacy and understanding of scientific inquiry. A survey was developed referencing the National Science Education Standards for Inquiry and previous work in the area. Two groups of elementary education students participated in the survey in two academic semesters. A semi-structured interview was conducted with a subset of the participants. Likert-scale survey results were analyzed statistically. Open ended survey responses and interview transcripts were coded qualitatively. Our ongoing goal is to compare results with those from an earlier study at the beginning of the 21st century. We hope to capture some evolutionary patterns in pre-service elementary teachers' understandings of scientific inquiry and generate implications to elementary science education, particularly concerning the evident shift away from an emphasis on usage of the term "scientific inquiry" in the Next Generation Science Standards.