This study examines the effectiveness of pre-laboratory presentations in an undergraduate general chemistry laboratory using two different modes of delivery: a traditional lecture versus an in-class video presentation. It was anticipated that implementation of videos could result in improved laboratory efficiency, safety, and necessary technical…

When a college instructor goes out of town and must miss a lecture, the standard options are to cancel the class meeting or to enlist a colleague to fill in. In the former case a teaching opportunity is lost; in the latter the substitute may not lead the class in the same way as the instructor. Some students routinely skip lectures by a guest…