A constructivist approach to inquiry-based learning: A TUNEL assay for the detection of apoptosis in cheek cells

Learning is an active process emphasizing purposeful interaction and the use of knowledge in a meaningful environment. Scientific experiments are, by nature, inquiry-based activities; developing scientists must learn to propose hypotheses, design experiments, and select appropriate materials. Many cognitive psychologists have portrayed learning as a process of creating individual meaning and understanding from personal experiences, a perspective referred to as constructivism (Ormond, 1998). Greater retention via long-term memory storage and future retrieval is thought to be a significant advantage of constructivism. In this model, students are encouraged to assume responsibility for their own learning (Figure 1). Students gain understanding by participating in activities in a laboratory setting and, thus, teachers should think about how to provide opportunities for active mental processing by students (Gabler & Schroeder, 2003). For example, diverse environments encourage inquiry and build new knowledge, allowing students to recognize the need for change. Moreover, encouraging students to apply knowledge while practicing skills promotes higher-level thinking and fosters a greater understanding of major concepts. The successful application of constructivism to student learning requires a few key factors: 1. prior knowledge in the content area in the form of lectures, directed readings, and group discussions 2. attainment of conceptual meaning (e.g., apoptosis and cancer) 3. articulation of experimental design and application (i.e., pre-laboratory proposal) 4. sufficiently structured experiences (i.e., laboratory exercise). A laboratory exercise is presented that incorporates constructivist principles into a learning experience designed for upper-level university biology courses. There are typically 15-20 students in our laboratory and students work in groups of three to four. Two full laboratory sessions are required for the completion of this experiment. The specific objectives for this exercise are as follows: 1. to introduce students to cancer biology and to the regulation of programmed cell death as part of the cell cycle 2. to engage students in scientific inquiry through experimental design and testing, using a constructivist approach 3. to encourage cooperative learning in a scientific laboratory setting 4. to promote scientific thinking and writing in the form of a laboratory report. [FIGURE 1 OMITTED] While we have designed this experience primarily for college courses, it may also be adaptable to certain high school curricula. The exercise is aligned with several of the National Science Education Standards (NRC, 1996). This laboratory experience is aligned with the Science as Inquiry standard in that students are exposed to the basic elements of the scientific method within a constructivist framework. The students are required to formulate a hypothesis and to adapt and execute the experimental design to address the hypothesis. Students are supported in this process by instructor-facilitated review of the pre-laboratory group proposal in order to enhance the experimental design while maintaining maximum student input. Additionally, the post-laboratory discussions guide students to reflect on the experimental design and to analyze and interpret the data as well as to consider the process of scientific inquiry. In this way, the students engage the scientific method within an instructor-controlled environment. The post-laboratory assessment also encourages students to construct new hypotheses and to modify the experimental design based on the interpretation of their data consistent with the History and Nature of Science standard. Introductory lectures and group discussions facilitate an expanded understanding of the conceptual framework (i.e., cancer biology and cell cycle regulation) of the exercise as articulated in the Life Science (The Cell) content standard. …