Peer Instruction and Lecture Tutorials Equally Improve Student Learning in Introductory Geology Classes

INTRODUCTION College introductory science classes are typically the last opportunity that most students ever have to learn science in a formal setting. For that reason, these classes provide unusual challenges to instructors, given the variety of potential class outcomes, the number of topics, the range of expectations that students have for the class, their prior conceptual knowledge, their attitude towards science, and their diversity in learning styles (Bransford et al., 2000). Besides these challenges, surveys indicate that while instructors tend to overestimate pupils’ learning gains (Rovick et al., 1999; Diakidoy and Iordanou, 2003), students often struggle with course vocabulary and are typically unprepared to develop successful strategies to learn the material (Lee et al., 1995; McCarthy and Kuh, 2006). These characteristic struggles, coupled with traditional pedagogical methods that normally lead instructors to misjudge students’ understanding ultimately result in unchanged misconceptions about science and in little gain in conceptual knowledge. For example, it is well documented that traditional teaching methods produce small, negligible, or even negative gains in students’ knowledge and understanding of scientific concepts (Halloun and Hestenes, 1985; McDermott, 1990; Hake, 1998; Libarkin and Anderson, 2005). Part of the problem is associated with the tendency of students in traditional teaching classes to resort to memorization as their strategy to learn the material in response to a learning environment that does not foster conceptual understanding (Tobias, 1990, 1992). To increase students’ conceptual and knowledge understanding and to improve their attitude towards science, a consensus exists about the need to develop novel teaching strategies that are based on a new teaching paradigm in which the class dynamic is fundamentally altered from a teacher-centered to a student-centered approach (Johnson et al., 1991; National Research Council, 1997). In this new class dynamic, students engage in their own learning process, which has produced both better attitudes towards science (Reynolds and Peacock, 1998) and more accurate conceptual understanding (Crouch and Mazur, 2001; Prather et al., 2005; Lasry et al., 2008). These student-learning methods involve students discussing questions and solving problems in class, with a significant amount of work being done by students working in groups. The success of these active learning strategies (sensu Bransford et al., 2000) appears to be related to the notion that they allow new information to be fitted into existing cognitive structures, which promotes learning. In contrast, when students perceive no apparent connections of new information to their prior knowledge and beliefs, as it is typically the case in teacher-centered classes, the new information is memorized and discarded (Bransford et al., 2000). The dilemma for instructors is to determine the type of instructional method that would be best beneficial in her/his class, considering that a number of active learning strategies exist. Two strategies, in particular, have been shown to be useful in large introductory science classes: peer instruction (PI) and lecture tutorials (LTs). The main advantage of these instructional techniques from the instructor’s point of view is that they are relatively easy to implement since they flow easily with traditional lectures, which are the most familiar type of instruction to college instructors. From the learners’ perspective, these techniques have been shown to produce statistically measurable gains in concept understanding (Crouch and Mazur, 2001; Prather et al., 2005; McConnell et al., 2006; Lasry et al., 2008; Kortz et al., 2008). Both PI and LTs are approaches that improve learning because both involve active and cooperative learning, allow rapid feedback, Germán Mora 1