A STUDY OF HOW PRECURSOR KEY CONCEPTS FOR ORGANIC CHEMISTRY SUCCESS ARE UNDERSTOOOD BY GENERAL CHEMISTRY STUDENTS

1. A STUDY OF HOW PRECURSOR KEY CONCEPTS FOR ORGANIC CHEMISTRY SUCCESS ARE UNDERSTOOOD BY GENERAL CHEMISTRY STUDENTS By Pat Meyer, Western Michigan University

2. Purpose of the study • To determine how general chemistry students understand the key concepts most likely to enhance student performance in organic chemistry • Necessary preliminary step: survey organic chemistry instructors to find out what general chemistry key concepts are most important for their students to understand in order to do well.

3. Literature Review • A common error students make when they study organic chemistry is sensing the difficulty of the task before them and trying to memorize results and algorithms. Students wrongly believe that doing so gives them a sufficient grasp of the field. (Nahkleh, Lowry, & Mitchell, 1996). • Although the flashcard strategy will sometimes work for a while at the beginning of a student’s first organic chemistry course, the belief in this strategy’s appropriateness seems to stymie student performance in the long run (Bradley, Ulrich, Jones, & Jones, 2002). • The weaknesses of rote learning have been clearly demonstrated in the literature (Bodner 1986), (Pendely, Bretz, & Novak, 1994), (Pungente & Badger, 2003).

4. The Setting and the Research population • Volunteers were solicited from one Fall section and one Winter section of CHEM 110 (a traditional first-year general chemistry course) and information was collected regarding their time availability during the week. Random selection was performed on the list of subjects who both expressed interest and had a class/work schedule complementary to that of the interviewer. • The majority of the potential participants in this study were Caucasian, Midwestern USA students, and approximately 18-24 years of age. • They varied in the amount of previous college-level science experience, but the majority of them had only a fairly small amount or none at all.

5. Instrumentation • Covalent Bonding and Structure diagnostic instrument (Peterson, Treagust, & Garnett, 1989). The instrument consists of multiple-choice two-tiered items. The first part of each item asks about chemistry subject matter content, while the second part asks the subject to choose from a list of reasons why he or she picked a certain answer to the first part. • The second instrument, the Geometry and Polarity of Molecules diagnostic (Furió & Calatayud, 1996) deals with many of the same topics. It is not a two-tiered instrument, but rather a set of 16 single tier (traditional) multiple-choice questions, with three or four possible answers given.

6. Interview Protocol • Subjects were videotaped while attempting to work certain items and questions from the diagnostic instruments during individual sessions ranging from 45 minutes to an hour. • The subjects were encouraged to “think out loud” during their efforts. They were required to use a marker and large whiteboard for any scratch work they did during the interview. • Probes were used when no commentary was given, and secondary probes were sometimes used if a subject gave an interesting response to a certain item or question. • Subjects were compensated by a $15 cash payment and were encouraged by a bonus payment at the end of the series (an additional $15) if they participated in all four interviews.

7. Data Collection and Methodology • Out of 19 subjects, 16 completed all four interviews, eight in Fall and eight in Winter. • Subjects were asked 16 two-tiered items and up to 16 single-tiered questions during the four hours of interviewing. Questions were grouped by key concept during the interview sequence. • Transcription and coding procedures were preformed on the raw data from the videotapes. • Lectures and the textbook were carefully studied as a check. • When the correct and incorrect responses were studied, certain commonalities were found across several subjects. These responses needed to be grouped in some way to make the data more manageable for analysis because there were hundreds of responses and justifications collected from the subjects

8. Assertions 1-3 • Many students misunderstand the location and nature of intermolecular forces. • Some think electronegativity differences among atoms in a molecule are sufficient to make the molecule polar, regardless of spatial arrangement. • Most know that higher phase change temperatures imply stronger intermolecular attractions, but many do not understand the difference between covalent molecular and covalent network substances.

9. Assertions 4-6 • Many have difficulty deciding whether a molecule is polar or non-polar, often confusing bilateral symmetry with spatial symmetry in all three dimensions. • Many cannot reliably draw correct Lewis structures due to carelessness and overuse of flawed algorithms. • Many are confused by how electrons can both repel one other and facilitate bonding between atoms via orbitals – this seems oxymoronic to them.

10. Assertions 7-9 • Many cannot explain why the atoms of certain elements do not follow the octet rule and some believe the octet rule alone can determine the shape of a molecule. • Most do know that electronegativity and polarity are not adequate to determine the shape of a molecule – but some apply the VSEPR theory in incorrect ways. • Students do not reason significantly differently when working with various representations of molecules such as ball-and-stick models, molecular formulas, and Lewis structures.

11. Generalized Commentary • Subjects 4A, 5A, 8A, 9A, and 2B mentioned the problem of exceptions in chemistry. It seems to them that every time a rule is given, it will soon be broken, making them question the value of the rule in the first place. • Subject 4A noted that “Every time you get a rule, there’s always exceptions, and … the exception doesn’t follow the trend so you have to memorize these thousands of exceptions. Like the Periodic Table, boron doesn’t follow its bonding thing [the octet rule]… even the Periodic Table isn’t solid” (4A1:10). • Subject 8A (a fifth-year senior) in expressing frustration that this course was going to be the first C grade she ever earned: “I want it to click like everything else … but it doesn’t. They give us a rule and they come up with 20 exceptions and here’s why …” (8A2:30).

12. Generalized Commentary • Some subjects referred to the abstract quality of the discipline. • Subject 4A explained how she felt the subject was difficult because “I can’t see molecules” (4A1:57). • Subject 8A spoke of the “weirdness of chemistry … it’s out there… like science fiction (8A1:23). • Subject 6B, a second-year biology major, contrasted his major field with chemistry in explaining that biology is more hands-on and doesn’t involve things that are too small to directly observe (6B1:12). He was apparently unaware that molecular biology does focus on things too small to directly observe.

13. Further Research • A worthwhile investigation would be to expand and change the recruiting of subjects to focus on current organic chemistry students. The conceptual understanding of these students could be statistically compared with their organic chemistry exam scores to check the assumption that high performance on the items of the diagnostics really does correlate to high performance in the organic chemistry examination room. • Assuming there is a significant difference between the performance of these two samples, is the difference between the conceptions of pre-organic and current organic chemistry students merely a matter of degree (i.e. refinements of ideas) or does it reflect dramatic “paradigm-shifts” (Kuhn, 1970) in the subjects’ thinking? • Another expansion of the research sample, to include organic chemistry researchers in academia and industry. How would their performance and conceptions of the key ideas compare with that of students? The possibility exists that the key ideas revealed in the survey are not necessarily essential for high organic chemistry performance in career situations …

14. Acknowledgements • My family: James, Barbara, and Frank Meyer for their caring expressed in so many ways. • William Cobern, Marcia Fetters, Heather Petcovic, and Elke Schoffers for sharpening my writing and thinking. • Debra Stoyanoff and William Merrow for administrative and technical support, respectively. • My close friends Brian Nolan and Kimberly Jack, for listening and giving solid advice during my data collection and writing • My wife and best friend Cindy Meyer, for her patience, helpfulness, and confidence in me. Mere words can neither explain nor quantify how grateful I am for her role in my endeavors.

15. Works Cited Bodner, George M. (1986). Constructivism: A Theory of Knowledge. Journal of Chemical Education, 63 (10), 873-878. Bradley, Alexander Z., Ulrich, Scott M., Jones, Maitland Jr., & Jones, Stephanie M. (2002). Teaching the Sophomore Organic Course without a Lecture. Are You Crazy? Journal of Chemical Education, 79 (4) 514-519. Furió, C., & Calatayud, M. L. (1996). Difficulties with the Geometry and Polarity of Molecules: Beyond Misconceptions. Journal of Chemical Education, 73 (1), 36– 41. Kuhn, Thomas S. (1970). The Structure of Scientific Revolutions, 2nd edition. The University of Chicago Press: Chicago, p. 10-11. Nahkleh, Mary B.; Lowry, Kirsten A; & Mitchell, Richard C. (1996). Narrowing the Gap between Concepts and Algorithms in Freshman Chemistry. Journal of Chemical Education, 73 (8), 758 – 762. Pendley, Bradford D., Bretz, Richard L., & Novak, Joseph D. (1994). Concept Maps as a Tool To Assess Learning in Chemistry. Journal of Chemical Education, 71 (1), 9 – 15. Peterson, Raymond F., Treagust, David F., & Garnett, Patrick (1989). Development and Application of a Diagnostic Instrument to Evaluate Grade-11 and -12 Students’ Concepts of Covalent Bonding and Structure Following a Course of Instruction. Journal of Research In Science Teaching, 26 (4), 301-314. Pungente, Michael D., & Badger, Rodney A. (2003). Teaching Introductory Organic Chemistry: ‘Blooming’ beyond a Simple Taxonomy. Journal of Chemical Education, 80 (7), 779 – 784.