Abstract: Physics education research (PER) is the study of how people think about, learn, understand, and teach topics in and related to physics.  One goal of PER is to identify student difficulties with a particular topic and to develop curricular materials to address these difficulties.  Results in PER show that guided-inquiry worksheet activities (a.k.a. tutorials) can be effective supplements to traditional lecture instruction in introductory physics classes.  Recent research suggests that tutorials can also be useful within advanced courses.  He will present some of the major findings from the PER literature as well as his own research into developing tutorials for use within advanced undergraduate thermal physics courses.