Three direct complexometric titration methods for bismuth subsalicylate determination in over-the-counter stomach relief caplets and liquids are presented, as well as a UV-vis assay, for use in student laboratories. The main difference between titration methods is the choice of indicator; either xylenol orange (XO), pyrocatechol violet (PV), or…

The Department of Physics at EKU [Eastern Kentucky University] with support from the National Science Foundations Course Curriculum and Laboratory Improvement Program has successfully converted our entire introductory physics sequence, both algebra-based and calculus-based courses, to an activity-based format where laboratory activities,…

A major challenge in conducting classroom experiments for larger classes is the complexity of assembling responses and reporting feedback to students. The author demonstrates how mobile phone text messaging can be used to overcome the limitations of pencil-and-paper experiments without incurring the costs of full computerization. Students submit…

Propensity score analysis is one statistical technique that can be applied to observational data to mimic randomization and thus can be used to estimate causal effects in studies in which the researchers have not applied randomization. In this article the authors (a) describe propensity score methodology and (b) demonstrate its application using…