ABSTRACT: Instructional physics labs often aim for students to observe classic physics phenomena. In this talk, I will describe research that demonstrates significant issues with such concepts-based labs, including limited impacts on student learning of the concepts being observed and student expectations that knowledge comes from authority. I will then describe a new approach to lab instruction that focuses on developing experimental skills. I will also present data about student expectations for how they construct knowledge in skills-based labs and the extent to which students engage in peer interactions in concepts-based versus skills-based labs.