  Instructional physics labs are critical junctures for many STEM majors to
develop an understanding of experimentation in the sciences. Students can
acquire useful experimental skills and grow their identities as scientists.
However, many traditionally-instructed labs do not necessarily involve
authentic physics experimentation features in their curricula. Recent research
calls for a reformation in undergraduate labs to incorporate more student
agency and choice in the learning processes. In our institution, we have
adopted open-ended lab teaching in the introductory physics courses. By using
reformed curricula that provide higher student agency, we analyzed
approximately 100 students in the introductory-level lab courses to examine
their views towards the open-ended physics labs. Between the start and the end
of the semester, we found a statistically significant shift in students'
perceptions about the agency afforded in lab activities. We also examined
students' responses to "Which lab unit was your favorite and why?". The
analysis showed that majority of the students preferred Project Lab, which had
the highest student agency and coding analysis showed that "freedom" was the
most frequent response for students' reason for picking Project Lab. Finally,
we also examined student views across gender and found no significant gender
effect on students' sense of agency.
