In the Classroom
Protein-Sequencing Jigsaw C. Michele Davis-McGibony Department of Chemistry, Georgia Southern University, Statesboro, Georgia 30460-8064
[email protected] In the field of chemical and molecular biology education, traditional didactic lecture is still the main method of operation for most college professors. However, the idea of active learning (1-9), problem-based learning (10-12), or guided-inquiry learning (13-16) has been the subject of numerous articles and presentations and has permeated most college campuses. The salient point of all these articles is that students learn complex science curricula best when working together in small interactive groups. The jigsaw technique is another cooperative-learning strategy that has been used for over 30 years in the elementary and middle school classroom (17-19) and was recently used in a chemistry high school in Germany (20) but has yet to find its way into the college arena. The jigsaw classroom has been shown to increase positive educational outcomes while reducing conflict within a specific classroom. This technique was first employed in the early 1970s during the time of integration to diminish racial conflict. The key to this system is that each piece (each student's part) is necessary for the completion of the final product. This technique is simple to employ in any classroom. Students are divided into “home” groups of four, five, or six students each (for example, 25 students will yield 5 groups of 5 students each), and each group is responsible for solving a particular problem or portion of the assignment. Once each home group has completed
their segment, the instructor assigns one member from each home group into new groups, the “jigsaw” groups. In the jigsaw group the students share information and complete the entire assignment. Each person in the jigsaw group is responsible for teaching their piece of the assignment to the others in the group. The benefit of the jigsaw class is that is an efficient way to learn the material while encouraging listening, engagement, and empathy by giving each member of the group an essential part to play. No student can completely succeed unless everyone works well together as a team. This technique could be used with any type of problem-based topic such as protein sequencing, plasmid mapping, DNA sequencing, Lewis structures, molecular shapes, stereogenic centers, buffer problems, spectroscopy, and many others. Protein sequencing is a classic type of problem in most biochemistry textbooks and courses. While few laboratories do their own protein sequencing these days, the critical-thinking and problem-solving skills learned while working on these types of problems is invaluable to biochemistry students. In my experience, protein-sequencing problem solving is something students pick up very easily or struggle desperately with. There is very little middle ground. Therefore, to improve student problem-solving skills I employed the jigsaw technique to protein-sequencing problems.
Figure 1. Final exam protein-sequencing problem. (Final exams are not returned to the student in the course, so this problem was identical on all four classes analyzed. This problem was adapted from ref 21).
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In the Classroom
Jigsaw Execution In traditional lecture style, all the reagents (both enzymatic and chemical) and methods for protein sequencing were introduced and explained to the members of the class one day in advance of jigsaw exercise. In the next class meeting, students were divided into home groups by giving each student a number-letter combination, for example, 1A, 2A, 3A, 4A, 5A, 1B, 2B, and so forth. My class was divided into five groups of five students each. A handout with five protein-sequencing problems that differed in the difficulty level and the type of problemsolving method required were handed out to the class. Students were instructed that group 1 (all number 1s) should focus on problem 1; group 2 should focus on problem 2, and so forth. Each group was given 20 min to solve their particular problem
and put the answer on the board. Once the 20 min were up, the groups were reshuffled into the jigsaw letter groups (all As, all Bs, etc.) for approximately 20 min. Each student in the jigsaw group was responsible for explaining the problem-solving method required for their problem to the group and answer any questions the other members may have. If any disagreements come up, the group could ask permission from the instructor to modify the answer on the board. At the end of the period, I gave the entire class a bonus point for each correct answer on the board, and if they were not correct I explained the correct answer. Assessment To determine if this active-learning technique was beneficial to the student I compared the scores on the exam that
Figure 2. Sample protein-sequencing problems from exam 2. The two problems are from different exams; however, they are similar in difficulty and problem-solving method.
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In the Classroom Table 1. Comparison of Average Scores on Exam 2 and the Final Exam Overall Average Score (%) Semester
Exam 2
Final Exam
Fall 2007a 78 ( 11.3 75 ( 12.1
Average Score for the Protein-Sequence Problem (%) Exam 2
Final Exam
85 ( 3.4
82 ( 3.2
Fall 2005
75 ( 13.5
72 ( 13.0
65 ( 3.1
51 ( 2.8
Fall 2004
76 ( 12.0
68 ( 12.2
70 ( 2.5
63 ( 3.2
Fall 2003
74 ( 11.5
71 ( 11.6
67 ( 2.5
58 ( 4.1
a
From these results, I would recommend the jigsaw method to any teacher to enhance problem-solving skills in their classroom. Literature Cited 1. 2. 3. 4. 5.
The values in bolded are from the semester with the jigsaw exercise.
covered protein sequencing and the final exam. The population of each class was approximately 24 students, and I compared the group that participated in the active-learning technique with three previous classes that did not participate in this particular active-learning exercise. To determine if this method was effective, I compared their overall scores and their score on the protein-sequencing portion of both their final exam and on exam 2. The exact problem from the final exam is given in Figure 1, and two representative sample problems from exam 2 are given in Figure 2. From my data, the employment of this particular learning technique increased overall student scores on exam 2 (containing the protein-sequencing portion) and the final exam slightly but not within a standard deviation. The remarkable results came during comparison of the protein-sequencing problem only. Students in the fall 2007 class saw an increase of 15% on average on exam 2 and a 25% increase on the final exam score when analyzing the protein-sequencing portion only (Table 1). Student comments about the jigsaw method on the end of year course evaluations were positive as well. One comment in particular stands out At first I had no idea how to work the protein-sequencing problems, but after discussions with my group we came up with an excellent way to solve them. Thanks for making us do this on our own! I actually learned how.
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6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.
20. 21.
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Capps, K. J. Chem. Educ. 2008, 85–518. Bobich, J. A. J. Chem. Educ. 2008, 85, 234–236. Chambers, K. A.; Blake, B. J. Chem. Educ. 2007, 84, 1130–1135. Oliver-Hoyo, M. T.; Allen, D. J. Chem. Educ. 2005, 82, 944–949. Oliver-Hoyo, M. T.; Allen, D.; Hunt, W. F.; Hutson, J.; Pitts, A. J. Chem. Educ. 2004, 81, 441–448. Seetharaman, M.; Musier-Forsyth, K. J. Chem. Educ. 2003, 80, 1404–1407. Grabowski, J. J.; Price, M. L. J. Chem. Educ. 2003, 80, 967. Burke, K. A.; Greenbowe, T. J.; Lewis, E. L.; Peace, G. E. J. Chem. Educ. 2002, 79, 699. Koether, M. C.; Munafo, C. R. Chem. Educ. 2002, 7 (4), 211–213. Hodges, L. C.; Harvey, L. C. Chem. Educ. 2006, 8 (6), 346–351. Conway, J. F.; Little, P. J. J. Scholar. Teach. Learn. 2004, 4 (1), 25– 36. Rosenberg, R. E. J. Chem. Educ. 2007, 84, 1474–1476. Bernard, E.; Britz-McKibbin, P.; Gernigon, N. J. Chem. Educ. 2007, 84, 1159–1161. Gaddis, B. A.; Schoffstall, A. M. J. Chem. Educ. 2007, 84, 848–851. Otto, W. H.; Larive, C. K.; Mason, S. L.; Robinson, J. B.; Heppert, J. A.; Ellis, J. D. J. Chem. Educ. 2005, 82, 1552–1554. Montes, I.; Lai, C.; Sanabria, D. J. Chem. Educ. 2003, 80, 447–449. Aronson, E. Jigsaw Classroom. http://www.jigsaw.org/ (accessed Jan 2010). Aronson, E. Nobody Left To Hate: Teaching Compassion after Columbine; W. H. Freeman: New York, 2000; pp 15-63. Aronson, E.; Patnoe, S. The Jigsaw Classroom: Building Cooperation in the Classroom, 2nd ed.; Addison Wesley Longman: New York, 1997; pp 12-39. Eilks, I. J. Chem. Educ. 2005, 82, 313–319. Garrett, R. H.; Grisham, C. M. Biochemistry, updated 3rd ed.; Brooks/Cole: Belmont, CA, 2007; pp 145-146.
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