  The physics community explores and explains the physical world through a
blend of theoretical and experimental studies. The future of physics as a
discipline depends on training of students in both the theoretical and
experimental aspects of the field. However, while student learning within
lecture courses has been the subject of extensive research, lab courses remain
relatively under-studied. In particular, there is little, if any, data
available that addresses the effectiveness of physics lab courses at
encouraging students to recognize the nature and importance of experimental
physics within the discipline as a whole. To address this gap, we present the
first large-scale, national study ($N_{institutions}=75$ and
$N_{students}=7167$) of undergraduate physics lab courses through analysis of
students' responses to a research-validated assessment designed to investigate
students' beliefs about the nature of experimental physics. We find that
students often enter and leave physics lab courses with ideas about
experimental physics as practiced in their courses that are inconsistent with
the views of practicing experimental physicists, and this trend holds at both
the introductory and upper-division levels. Despite this inconsistency, we find
that both introductory and upper-division students are able to accurately
predict the expert-like response even in cases where their views about
experimentation in their lab courses disagree. These finding have implications
for the recruitment, retention, and adequate preparation of students in
physics.
