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

One interesting trend in the 8th grade students' responses uncovered through analysis of the posttest watershed drawings was that many students drew a lake as a complete ending point to the watershed (Table 3, Table 4). While the presence of a lake does not mean the drawing of the watershed is incorrect, a lake is not a necessary component of a watershed, and we felt it was important that students are made aware of this fact. Both the presentation and the model featured watersheds ending in lakes, since the local environmental issue is based on the Lake Shafer scenario, which probably contributed to the prevalence of lakes in the students' responses. Thus, future presentations should be altered to illustrate a wider variety of watersheds to broaden students' watershed conception.

Question 2: What are E. coli? - This is an open-ended question that gave students the freedom to write as much as they knew about the topic. E. coli is the pollutant of concern in this local community environmental problem; therefore, it is important to determine how much students know about E. coli. Based on the pretest, most of the students knew E. coli was some form of microscopic organism. Many also believed E. coli is only harmful to humans, and were not aware of its important role in the human digestive system (Table 5). This belief most likely arose from the solely negative media publicity given to E. coli in the Lake Sharer area. Students build both scientific understanding and misconceptions at least partly from observations and experiences in the world around them (Byers and Fitzgerald, 2002). There was one case in which a student knew exactly what E. coli are, because her family had suffered E. coli poisoning from their own water well. This illustrates how well students learn from issues that directly impact their lives, and the importance for educational programs to utilize these issues to promote student interest and learning while getting students involved with the community.

The assessment of posttest responses indicates that the presentation and activity decreased the misconception that E. coli is harmful and the additional information acquired through learning allowed the student to associate E. coli with more than water contamination (Table 3). While E. coli is a source of concern for this local community, it is important to supply the students with a well-rounded background regarding E. coli, rather than "terrifying" them with the possible consequences of water contamination. After the presentation, students in school 6 and school 8B had a significant decrease (P

Question 3: Using the data from the table below, plot and label the graph - The third question is quantitative and asks students to create a graph displaying data they were given (Table 6). There is a definite right and wrong answer to determine if students can apply a methodical strategy to solve a straightforward problem. The presentation introduces the concept of collecting, analyzing, and visually displaying the data, and the activity has students replicate what they learned in the presentation; thereby, reinforcing the material while it is fresh in their mind. There was a sharp distinction between the capabilities of the sixth grade and the eighth grade students in the pretest. The sixth grade students had problems graphing two different sets of data on the same graph; however, those that attempted to create the graph chose to display their data using a line graph. The overall improvement from pretest to posttest for the students, with respect to completely drawing the graph correctly (Table 8), was significant with an overall probability (P0) = 0.0001, which is presumably due to the success of the presentation and hands-on activity.