After teaching general chemistry to science majors, I became interested in studying three dilemmas that emerged from my experience:
1. Finding out the student’s views of explanations by getting students’ input on how explanations help them understand;
2. Discovering what sensitivities on the part of the explainer are necessary for her explanations to be successful in individual students’ eyes; and
3. Learning how to palatably fulfill for students my standards for critical thinking and deeper student learning while making the method and organization transparent.
After showing the study and some of its results, I explain my classroom responses to knowing more about my chemistry students and explanations from their student landscape.
Three dilemmas attacked
An undergraduate researcher and I developed an open-ended questionnaire to distribute to CHEM 188 students during the summer. This course is the second semester of a year-long general chemistry sequence. Our questions probed 42 students about their beliefs and experience on the following: What are the pragmatic purposes of explanations? What do students believe needs an explanation? What makes an explanation successful in terms of its “explanatory power” for a student? For example, do explanations fare better if they are physical or hands on, if clear and simple, if repetitive, if a demonstration? Finally, when is an explanation irrelevant to students? We also probed what aspects of explanations and their presentation students desired when they sought explanations. For example, we wondered if good explanations were sensitive to student reasoning in everyday events (commonsensical thinking) and whether domain-specific explanations needed to be sensitive to that particular human everyday kind of reasoning to be effective. Further, we wondered whether students would point out the importance to them of representations that cemented an explanation, such as perceptual or symbolic ones, or physical or three-dimensional models. Were deeper representations that illustrated the connection and distinctions between our readily apparent macroscopic, mechanical world and the world of molecules and their mechanical processes important?
My interest in critical thinking and understanding requires that students be willing, or able to become willing, to take more responsibility for their learning by reasoning and talking in the discipline. The key to student involvement in critical thinking is the issue of relevance that we’ve all heard about many times: Enough and the right kind of relevance can motivate students to do the extra work of thinking rather than merely receiving knowledge from an authority figure. I wonder sometimes whether we professors realize how science instruction shows science as very similar to other authority-based institutions. For example, if students buy into the authority of the mouthpiece at the podium rather than expect to be guided through scientific reasoning about aspects of the natural world, what viewpoint of science have instructors condoned? We must judge whether facts of the discipline as sole content are important enough to squelch the development of disciplinary reasoning. I believe science professors must weigh the critical-thinking conception together with the content conception of teaching on the bases of attributes of each, a balance of each, and a way to provide opportunities for continuous interplay of disciplinary facts with reasoning.
Results
How students view explanations. The purpose of the initial survey was to see the various connotations and usages of the term, explanation, the issue of relevance in explanations, and student’s individual meaning for the goal of understanding. We saw that they mentioned four different aspects of explanation that we organized into quadrants: One axis has (a) what needs explanation (natural phenomena) versus (b) standards for a good explanation; the other axis has (c) explanations given publicly versus explanations used privately to build understanding. As to what needs explanation, students mentioned explanations about three aspects of knowledge: facts of the discipline that were related to natural phenomena; procedural knowledge such as how, when, or what to do; and a clear desire for applications of the knowledge that we assumed meant how that knowledge contributed to a natural phenomenon and how this knowledge is used in other applications.
Our results showed generally that the students’ sphere of relevance is less like a sphere than it is like another layer of skin on their bodies. For example, they responded that they needed explanations related closely to their knowledge which were relevant to them personally. Generally, students expect clear explanations of content they need to know. They want explanations that are simple as opposed to complex or technical, concrete as opposed to abstract, and closely linked to their current knowledge. Private standards for a valued explanation were personal connections to their aptitude, intelligence, and learning style. Overall, reasons made ideas more comprehensible for them. I was happy to notice that a significant number said good explanations helped in comprehension and in remembering, because these inspired confidence that many students might be organizing knowledge for the long term rather than for short-term test performance.
My undergraduate researcher and I constructed a second multiple-choice survey from the data supplied by the initial open-ended response survey. This anonymous survey was given to the CHEM 184 students during the first chemistry lab session with questions on explanations, learning approaches, and demographics, which were given at the start of all large chemistry classes I’ve taught, just to get a better conception of the student population. Questions about learning approach measured rote and meaningful learning strategies. In this paper, I focus on parts of the database rather than the whole: data from the first survey on explanations, demographic data from the second survey, data on prior knowledge from the diagnostic exam, and student comments during the course and from my evaluations at the end of the semester.
Student demographics in fall general chemistry. The large (over 800) fall semester student population of general chemistry, CHEM 184, which is designed for science and engineering majors, is wildly diverse, both in number of variables important to learning chemistry and the wide range among students on each of these key variables. Completion of prior chemistry classes range from none (10%) to two years (nearly 20%), including AP chemistry; about 60% have had one year of high school chemistry. The prior lab experience ranges from none to a considerable amount. Math preparation is quite variable along a continuum from uncomfortable with algebra to completion of a year of calculus. These majors vary among their areas of study and career plans: engineering, physical sciences, pharmacy, molecular biosciences, zoology, botany, premedicine and allied health sciences, and exercise science. See Table 1 for specific details of diversity distributions on each factor.
| Gender | 52% female | 48% male | |||
| Previous Schooling | 95% US or Canada | 1% Asia | 1% Mexico, Central, or South America | 1.5% Middle East | 0.5% Europe |
| Year in College | 60% freshmen | 20% sophomores | 12% juniors | 6% seniors | 1% graduate or professional school |
| Percent of class: 36% physical science majors | 20% engineering | 10% pharmacy | 2.5% chemistry | 2.5% geology | 1% physics |
| 48% life science majors | 23% premedicine | 13% pure biology | 5% exercise science | 4% allied health | 3% biochemistry |
| 15% undecided major | 8% which science major | 8% but not science major | |||
| Math preparation: 13% don't meet prerequisite | 9% no precalculus | 4% enrolled in precalculus | 6% completed precalculus | 32% enrolled in calculus | 47% had some calculus |
| Chemistry preparation: Most recent | 10% no high school chemistry | 60% one year high school chemistry | 11% one year AP high school chemistry | 8% two years high school chemistry | 10% college chemistry |
| 10% most recent college chemistry | 2% repeating CHEM 184 | 4% one semester community college | 3% KU's CHEM 124/5 | 1% two semesters community college | |
| Job time/week | 40% 0-5 hrs | 18% 5-10 hrs | 30% 10-15 hrs | 10% 15-20 hrs | 2% 30+ hrs |
| CHEM 188 enrollment | 11% no | 7% probably no | 26% don't know | 17% maybe yes | 39% yes |
Prior chemical knowledge distribution. A diagnostic exam identified students personally and provided insight into their current level of chemical knowledge (as could be measured by a multiple choice, standardized exam). The mean for current knowledge was 49%, but the scores varied from 9% to 95% on a 44-question diagnostic exam, which is a remarkably wide range for background knowledge in a course.
Figure 1 shows the distribution graphically. Since 90% of these students finished a chemistry course(s) in high school or college, I predicted a narrower range than was found. The diagnostic score represents a number of factors; for example:
• Did a student have a strong chemistry course?
• Is the student comfortable using algebra and solving problems?
• Did she or he learn for long-term understanding?
Our fall honors class, CHEM 185, enrolls 50 well-prepared students. The average diagnostic score for those students is about 75%. Other well-prepared students prefer to enroll in CHEM 184, which they perceive correctly as easier; some drop 185 and enroll in 184 after they realize the workload and math level in 185.
More advanced courses in the chemical curriculum don’t have remarkably wide background knowledge diversity, because the background knowledge that students possess beyond general chemistry has generally arisen from common sources. Students have considerably less previous background about topics in the second semester of general chemistry, and little or none in organic, analytical, or physical chemistry. In organic and upper division chemistry, students’ knowledge levels vary most often for individual student reasons. The wide range in general chemistry, in contrast, goes beyond individual differences and clearly indicates a wide range of opportunities to enroll in one, two, or advanced placement chemistry. One cause for 10% of students enrolling in CHEM 184 without high school chemistry is lack of career knowledge. Some students, particularly those interested in health occupations, were more likely to take a second year of biology in high school. They got to KU surprised they needed chemistry.
Changes to the course
My account ends with the story of how I approached CHEM 184 this fall as a result of this new knowledge from students and what has happened concerning the seeming contradictions about the nature of good explanations, good organization, and relevance between me and my students.
The knowledge that students want explanations that are personally relevant to them was illuminating, especially when imagining how to meet the following challenge in a large, diverse undergraduate class: Needed explanations should be closely related to their knowledge, clear about content that students need to know, plus simple, non technical, non-complex, and concrete as opposed to abstract. Furthermore, students wished for personal connections to their aptitude, intelligence, and learning styles.
Since it was impossible to meet individual needs for personal relevance in a large, diverse class, the only strategy that seemed viable was creating personal relevance. Created personal relevance for all students could be a common experience among all motivated class members who planned to do well. I decided to create personal relevance by the kinds of requirements and activities that the course contained. Table 2 illustrates the learning environment, curricular, assignment-oriented, and assessment features that could provide a common sense of relevance. The table gives an over-view of my reasoning.
I noticed several changes that occurred as a result of making problem solving the central feature of lectures. One of them was that lecture time was quite highly focused. I found writing lectures to be remarkably different when organized around problems to be solved in class. Second, the format of the class became predictable; something I hoped would make the organization more transparent (but possibly boring). Another benefit of problems was that the important concepts were clearly identified by me as those needed to solve end-of-the-chapter problems that I modeled during lecture. I hoped that students would come to recognize this fact at “gut-level.” I am making the distinction between intellectual knowledge gained when someone tells you information versus realizing the implications of knowing something. Finally, a significant portion of the class was spent at the overhead, where I wrote, spoke, drew pictures, and generally reasoned out loud. I did the problems prior to class in fairly large print. During class I reproduced them for students in real time.
Many students told me they hated to miss class because they missed the kinds of problems done that day. Thinking about the diversity, these students were probably less comfortable with chemistry or with math applications or found that they didn’t remember very much from previous chemistry classes. Since 20% of the class had two years of high school chemistry or AP chemistry, these students were likely to be bored by the format and the tedium of problems, which they didn’t find problematic. Many students told me I talked too fast at 8:30 in the morning; they couldn’t get everything down. Other students told me that the class was unbelievably slow for a college-level class. After seeing the multiple diversity spectra, you can believe such dichotomous comments were fairly routine occurrences.
The class was less vague, more focused on problems, and busy for students in terms of weekly or 10-day assignments. More serious difficulties than slowness or boredom lifted their ugly faces; that is, differences in the meanings of understanding, the purpose of reasoning through concepts, and scientific explanations versus personal explanations of science. One example became very common: Understanding as the “right answer,” and explanations as procedural explanations about how to get the right answer. One student, let’s call her Student A, who did very poorly on an exam (52%) said to me, “But I understood everything perfectly when I went in to take the exam. How could I only get a 52?” (I was puzzled as to what “understanding perfectly” meant because I can’t recall ever saying that I understood something perfectly.) So our problem is one of determining what she meant by understanding, particularly if it could be perfect. She told me had a wonderful high school class. During the conversation I looked up her diagnostic score. If you recall the mean of the diagnostic exam was 49%; her score was only 29%. One of her high school friends in our class, who took the same high school course, scored much closer to the mean, 43%. In a case such as this it seemed as if Student A wasn’t getting chemistry into long-term memory, which is often the case when students memorize definitions and algorithms rather than attempt to understand how things work. Two consequences of holding a definition of understanding like Student A’s are: 1. She didn’t do well on a college diagnostic exam; and 2. She wasn’t doing well in college chemistry using the same strategies. As we tried to discuss her situation I tried to steer her towards thinking about changing how she studied, but she was very defensive and angry.
Another Student (B), who performed nearly as poorly, explained, “You only do the easy problems in class. I know because I’ve gotten many of the right answers and then didn’t have to listen anymore.” Reasoning about problems is the action that explains why we incorporate particular and important concepts, which should increase applicability of concepts to other problems. The purpose of my taking time to reason was lost to Student B. Second, we have to take into account that most of us have experienced how much easier it is to watch someone else do something than it is to do it ourselves after watching. Many students use answer books as study manuals rather than references. The student looks at how the problem was done, thinks “That makes sense,” and moves on, without seeming to realize a rather large gap exists between observation and doing. When it comes to solving a problem similar to those read about in the solution manual, she or he may not remember the crucial parts to execute. We usually remember aspects of a problem with which we struggled and may have even required us to look at the solution manual. Without personal struggle and reasoning, students really don’t know the essences of solving problems such as those I practice in class and in their homework. I began to notice that many students were treating the online homework problems like a battle of wits with the computer—instead of reasoning, they were getting quick feedback and then trying to figure out what was wrong in their reasoning if the problem was incorrectly done.
Conclusions and comments
The changes were met with mixed results. Some students didn’t see organization and complained about it on evaluations. Many still found that my explanations didn’t help them and, in fact, confused them so much they had to study the book. A few individuals commented on the reasoning through problems, but mostly to point out that I didn’t take all the steps, went too fast, or only solved the most trivial of problems. Many students still saw no relevance of lecture to exams and complained that they had to teach themselves. Generally, many students seemed to hate this approach. Student evaluations are not given to me as a file, so I can’t check for statistical correlations between questions so as to group student statements that might enable inferring their background levels. I have a hunch that the most irritated students are those with significant background knowledge, such as several students who said the class needed to be much more challenging. I suspect they would have been eligible for CHEM 185 but didn’t want to risk a lower grade. But these are mere speculations without correlational data.
In conclusion about my study of three dilemmas that emerged from teaching general chemistry to science and engineering majors, I discovered at a much deeper level that many, many students do not have the same meaning for the terms, understanding, and explanation that I utilize when I lecture, design problem sets, or write exam questions. For students, explanations function as personal tools to successfully do what needs to be done (in their eyes). I discovered that the required sensitivities of me as the explainer were the following: relating to the individual’s knowledge level for the sake of clarity, using simple and non-technical explanations in fairly familiar language, and connecting with the individual’s learning style, intelligence, and interests. These are necessary for my explanations to be successful in individual student’s eyes. I have not yet come close to my goal of mastering how to fulfill standards for critical thinking and deeper student learning, which are palatable to 75-80% of students, and which at the same time give the method and organization transparence. Now what are my scholarly classroom responses to knowing even more from their student landscape? After every course I waver about whether I ought to teach more in the manner in which I was taught science, and after this major scholarly effort, I feel discouragement that students will not buy in to my methods. As a newer professor, perhaps they hope I won’t stay around long enough to “get my way.”
What about students achieving “gut-level knowledge,” referring to the distinction between knowing the implications of knowledge because of work done on those concepts versus intellectual knowledge gained when someone tells you information? I feel discouraged that many university students are so focused on jumping through hoops that they can’t slow down to smell the roses, experiencing the beauty of disciplinary thinking. As faculty members we have to consider whether by not pushing and by not modeling disciplinary reasoning we disadvantage our students. Student evaluations will probably seldom complain that students didn’t get enough chances to reason scientifically through the course. I would love to be wrong! We all realize, of course, that it will require a change in the professorial role that consistently expects reasoning performance from students in each discipline. It might not even require waiting too long to hear KU faculty say, “Gee, these students sure can think!”
Janet Bond-Robinson is an assistant professor of chemistry. She came to KU as a post doc in 1998 and accepted a faculty position five years ago. She teaches various courses including College Chemistry for non-science majors, Foundations of Chemistry for science majors, a senior seminar for chemistry majors, and a graduate course titled “Teaching New Graduate Students to Facilitate Undergraduate Learning.”
