The active-learning activities incorporated into Chemistry 465 include in-class problem solving with PowderCell software; during these activities, the instructor and his students work on exercises similar to the homework exercises that students complete outside of class.
For instance, the instructor directs his students to use their tablet PCs to open a file containing the X-ray powder-diffraction pattern of an unknown material and then identify the specific structure of the material’s unit cell.
Diffraction Pattern in PowderCell
The process of identification requires several steps, including:
Educated guessing to narrow down the type of crystal-lattice the material is likely to be
Refinement with PowderCell.
When the instructor introduces these exercises, he engages his students in a friendly competition, asking them to see who can produce the most successful refinement and encouraging them to achieve a better refinement than he achieves using PowderCell on the SMART Board.
Throughout these exercises, he prompts students’ thinking by asking a sequence of questions, such as “What should we try first? Why didn’t that work? . . . I’m not ready to give up. I think there is another possibility. Who can tell me what it is? . . . Do you notice anything different about this pattern?” This approach places the emphasis less on who achieves the best refinement than on how the student has achieved this result, and it encourages students to learn from one another.
In addition, the instructor’s questions underscore the idea that problem solving involves trial and error, along with careful observations and calculations, and a willingness to find alternative solutions when initial methods do not work as anticipated.