Using Assessment to Evaluate and Improve Inquiry-Based Geoenvironmental Science Activities: Case Study of a Middle School Watershed E. coli Investigation

Journal of Geoscience Education, Mar 2005 by Patterson, Lauren A, Harbor, Jon

An interactive presentation, hands-on activities, and a field/lab exercise were developed around the goal of assisting students to build their knowledge and experience of the scientific method in the context of learning content focused on water quality and E. coli. The effectiveness of some of the activities and materials in increasing student knowledge was assessed through pretests/posttests. Assessment of the students allowed analysis and measurement of the role of the activities in changing student knowledge and skills in relation to both scientific methods and skills, and to the content related to local community problems of water pollution. Based on assessment results, modifications to the materials were then made to create lessons better matched to the needs and abilities of the students. Continuous understanding and improvement of student learning is imperative and made possible through such assessments (Nuhfer, 1996).

METHODOLOGY

A variety of activities were created to make students aware of the science behind environmental issues associated with the Lake Shafer E. coli problem. These materials are available at http://www.eas.purdue.edu/geomorph/geoeducation/ecoli/index.html. In this study, we focus on an interactive PowerPoint presentation and a hands-on activity used with middle school students. The interactive PowerPoint presentation contained information regarding watersheds, E. coli, the local issue at Lake Sharer, and how to use the scientific method to determine major sources of E. coli. The hands-on activity reinforced the presentation by having students count E. coli from pictures of E. coli plates taken from locations upstream and downstream of potential sources of water pollution. The students worked in groups of three or four to count, graph, and interpret the data. Each group was provided with a different set of data, and was required to present its findings in front of the class. The materials were presented to each class in the following order: pretest, interactive presentation, hands-on activity, and the posttest. In this study the researchers acted as the teachers, both to provide consistent presentation of the materials and also with the goal of modeling use of the materials to increase likelihood of classroom teacher adoption (Huntoon et al, 2001).

Presentation of Materials - Two different schools agreed to participate in this project. In the first school (labeled school 6) 57 sixth graders participated simultaneously during a 1.5 hour time block. The large number of students and their many questions stretched the presentation to 45 minutes, the hands-on activity took 15 minutes to complete, and the remainder of the time was spent organizing students, collecting papers, and end of the day announcements. In the second school, the entire eighth grade class participated in the activities as well, but in a slightly different manner. The eighth grade class was large enough to warrant the students being divided between two different science teachers, and these two populations will be referred to here as school 8A (69 students) and school 8B (74 students). The eighth grade classes were taught during their regular periods of 40 minutes, and each class consisted of 15 to 20 students. Thus, due to time constraints, it was necessary to have the teachers deliver the pretest to the students the day before the presentation and hands-on activity. The teachers were given instructions to allow students 5 minutes for the pre-test, and not to offer any additional assistance. The smaller number of students enabled the presentation to move more quickly (about 25 minutes), as well as the hands on activity (about 10 minutes). These discrepancies between the 6th and 8th grade classes are significant limitations in this study; however, as guest lecturers we had to accept the conditions each school provided during our visit.