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An Approach for Large-Enrollment Chemistry Courses Melanie M. Cooper Clemson University, Clernson, SC 29634 One of the major goals of most chemistry instructors is to encourage their students to think and to apply the con- cepts that they learn. Although students may be able to reproduce specific types of calculations they have seen be- fore, many are unable to apply their knowledge to new sit- uations. In large enrollment courses where little, if any, personal interaction may occur between instructor and students, this problem may well go unnoticed until the first exam, where the student may be bewildered by ques- tions that require application of knowledge. One solution to this problem is the use of writing assignments. Care- fully crafted writing assienments allow students to reflect upon the materia1;and the reflection process provides a clearer understandine of the subiect matter. Writine about - - chemistry actively involves the student in the learning process-a prerequisite to a successful completion of the course. Writine in chemistrv courses usuallv has been associ- ated witc formalized l h r a t o r y reports", term papers, and research proposals. However, the use of other types of writ- ine assienments in chemistrv courses. usnallv in coniunc- - - tion with such movements as writing across the curricu- lum (1) and critical thinking (24), recently has gained increased prominence. These less formal writing experi- ences, in which the student is writing to learn, to organize, and to understand material are vitalprerequisites more formal writine tasks. Manv students omit such exercises and fail to resize that they are essential for the successful study of a subject. The fact that an average introductory chemistry course at Clemson Universily has around 200 students per sec- tion precludes many i f the more traditional writing as- sienments simolv bv weieht of numbers. Most teachers of - ." . - large enrollment courses probably would not have the time or G h a t i o n to read and grade200 essays several times oer semester. and manv would not feel oualified or able to give such a large number of essays the proper attention. Therefore, the format chosen for the assignments given to our eeneral chemistm students was that of note writine-a sho; (100-200 word, informal summary or description of the topic assigned. The short length of the note allows the teacher to read them fairly quickly, and the note format is useful to the students, because these future professional scientists and engineers often will be required to commu- nicate their ideas. in the form of a note or memorandum. The use of writing assignments, such as those described below, supplements other teaching and learning tools used in our Clemson chemistry courses and leads, we hope, to an increased understanding of the concepts to be learned. Examples of Assignments Examples of the different types of assignments and stu- dent responses are given below. The following is a pair of assignments that usually are given two or three lectures before a major test. Homework on Unanswered Questions Homework Assignment I Choose one topic that we have covered in class that you feel you do not understand. In about 150 words (1 page) summarize what it is that you do not understand or the pmhlem that you are experiencing. Note the following points. 1. Be specific about key points 2. Try to avoid blanket statements such as "I don't under- stand anything." 3. Think about whether you muld give an answer to your own question. Do not pose unanswerable problems. Bring two typed or clearly written copies to the next class. Homework Assignment ZI Exchange the homeworkasiignment due today with a neigh- bor. You will then have a question or statement about a princi- ple that your neighbor does not understand. Your assignment is to try to explain the principle troubling your neighbor. Aeain this assirmment should he brief and concise. Annmd- ma& 10&200 Lords should be suflirient. lbrn in yo& an- swer at the begmningoF the next class, stapled to the question you received. You also should bring a copy of your answer for your neighbor. We have found it important to give these rather detailed instructions. otherwise the students are not exactly sure of the requirements. In addition, students are given exam- ples of papers that are felt to have been of help by copying &pprop&& examples onto overhead transparencies that the instructor reads to the classes. For completion of this pair of assignments, the students are given credit equal to an "in class" quiz. Such a quiz would normally comprise less than 1% of the total grade and is negligible for most purposes. The student is given credit solely for completion of the exercise. No attempts are made to grade for content, spelling, or grammar. If an incorrect answer is given to another student the writer is asked to rectify the matter. Typical Set of Responses The following question and answer pair deals with the to~ic of limitine reaeents that students freauentlv find - - cokusing. The answer gives a succinct easy method for de- termination of the limitine r e a g e n h n e that the author - - now shares with the students. rNok: student exercises have been retyped for publica- tion here, but spelling and gramma; have n& been changed.) Problem Limiting reagent problems confuse me. I have trouble distin- guishing what the actual limitingreagentis. Is it the one that is entirely used up or the other? The math is not that difficult. My problem comes in the middle of the math aRer I find the actual moles. Once I finish the mole ratio part I find it hard to decide which is the limiting reagent. Answer The limiting reagent is the chemical that is completely used up. I fmd that the method Dr. Cooper uses on the board is too 476 Journal of Chemical Education

Writing: An approach for large-enrollment chemistry courses

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Page 1: Writing: An approach for large-enrollment chemistry courses

An Approach for Large-Enrollment Chemistry Courses

Melanie M. Cooper Clemson University, Clernson, SC 29634

One of the major goals of most chemistry instructors is to encourage their students to think and to apply the con- cepts that they learn. Although students may be able to reproduce specific types of calculations they have seen be- fore, many are unable to apply their knowledge to new sit- uations. In large enrollment courses where little, if any, personal interaction may occur between instructor and students, this problem may well go unnoticed until the first exam, where the student may be bewildered by ques- tions that require application of knowledge. One solution to this problem is the use of writing assignments. Care- fully crafted writing assienments allow students to reflect upon the materia1;and the reflection process provides a clearer understandine of the subiect matter. Writine about - - chemistry actively involves the student in the learning process-a prerequisite to a successful completion of the course.

Writine in chemistrv courses usuallv has been associ- ated witc formalized l h r a t o r y reports", term papers, and research proposals. However, the use of other types of writ- ine assienments in chemistrv courses. usnallv in coniunc- - - tion with such movements as writing across the curricu- lum (1) and critical thinking (24), recently has gained increased prominence. These less formal writing experi- ences, in which the student is writing to learn, to organize, and to understand material are vitalprerequisites more formal writine tasks. Manv students omit such exercises and fail to resize that they are essential for the successful study of a subject.

The fact that an average introductory chemistry course a t Clemson Universily has around 200 students per sec- tion precludes many i f the more traditional writing as- sienments simolv bv weieht of numbers. Most teachers of - . " . - large enrollment courses probably would not have the time or G h a t i o n to read and grade200 essays several times oer semester. and manv would not feel oualified or able to give such a large number of essays the proper attention. Therefore, the format chosen for the assignments given to our eeneral chemistm students was that of note writine-a sho; (100-200 word, informal summary or description of the topic assigned. The short length of the note allows the teacher to read them fairly quickly, and the note format is useful to the students, because these future professional scientists and engineers often will be required to commu- nicate their ideas. in the form of a note or memorandum.

The use of writing assignments, such as those described below, supplements other teaching and learning tools used in our Clemson chemistry courses and leads, we hope, to an increased understanding of the concepts to be learned.

Examples of Assignments Examples of the different types of assignments and stu-

dent responses are given below. The following is a pair of assignments that usually are given two or three lectures before a major test.

Homework on Unanswered Questions

Homework Assignment I Choose one topic that we have covered in class that you feel

you do not understand. In about 150 words (1 page) summarize what it is that you do not understand or the pmhlem that you are experiencing.

Note the following points.

1. Be specific about key points 2. Try to avoid blanket statements such as "I don't under-

stand anything." 3. Think about whether you muld give an answer to your

own question. Do not pose unanswerable problems.

Bring two typed or clearly written copies to the next class.

Homework Assignment ZI Exchange the homeworkasiignment due today with a neigh-

bor. You will then have a question or statement about a princi- ple that your neighbor does not understand. Your assignment is to try to explain the principle troubling your neighbor.

Aeain this assirmment should he brief and concise. Annmd- ma& 10&200 Lords should be suflirient. lbrn in yo& an- swer at the begmningoF the next class, stapled to the question you received. You also should bring a copy of your answer for your neighbor.

We have found i t important to give these rather detailed instructions. otherwise the students are not exactly sure of the requirements. In addition, students are given exam- ples of papers that are felt to have been of help by copying &pprop&& examples onto overhead transparencies that the instructor reads to the classes.

For completion of this pair of assignments, the students are given credit equal to an "in class" quiz. Such a quiz would normally comprise less than 1% of the total grade and is negligible for most purposes. The student is given credit solely for completion of the exercise. No attempts are made to grade for content, spelling, or grammar. If an incorrect answer is given to another student the writer is asked to rectify the matter.

Typical Set of Responses

The following question and answer pair deals with the t o ~ i c of limitine reaeents that students freauentlv find - - cokusing. The answer gives a succinct easy method for de- termination of the limitine r e a g e n h n e that the author - - now shares with the students.

rNok: student exercises have been retyped for publica- tion here, but spelling and gramma; have n& been changed.)

Problem Limiting reagent problems confuse me. I have trouble distin-

guishing what the actual limitingreagent is. Is it the one that is entirely used up or the other? The math is not that difficult. My problem comes in the middle of the math aRer I find the actual moles. Once I finish the mole ratio part I find it hard to decide which is the limiting reagent.

Answer The limiting reagent is the chemical that is completely used

up. I fmd that the method Dr. Cooper uses on the board is too

476 Journal of Chemical Education

Page 2: Writing: An approach for large-enrollment chemistry courses

sa raoidlv between dav and nieht that if anvthine still were confusing. I find a better to divide the number of molesofeach compound by its coefficient. The smallest resultrng number is tbat of the limiting reagent.

There are several benefits to this kind of exercise, one of which is that a path of communication is opened between the teacher and-students. manv of whom mieht not other- wise seek help or feedbaik on their progres~ Because the assienments are received bv the teacher several davs be- fore; test, it is possible to review the major problemareas in help sessions or in class. Using this system, feedback may be obtained on the areas in which students have the most nroblems. In some cases this information mav allow the i&wctor to change the approach or explanation, or spend more time on specific problem areas.

Perhaps the most important benefit is that of simply makine the students sit down and think about the mate- rial coiered. In addition, i t forces the students to try to organize the material in their minds well before the test. The process of thinking about the material they do not un- derstand and even learniw that they do not, in fact, un- derstand it can be a major breakthrough f& somestu- dents. Students have commented on this organizational process, and the help they have derived from these assign- ments.

A third area in which these assignments are he lp l l is the r e ~ l v Dmcess in which the student has to answer the question of a neighbor. The proeess of explaining a concept to someone else is oRen very useful in the clarification of ones own understanding of <he material. In fan, the bene- fits of peer learning and teaching are well documented (5).

Why Lewis Structures Are lmportanl

Another assignment may be given in which students have to explain why they are studying a certain principle. Unfortunatelv. i t is common for students to get lost in the mechanics ofsolving quantitative chemical problems and forget why they are required to solve these problems. Or, for example, many students do not appreciate why they are taught to draw Lewis structures. In the following exer- cise s tden t s were asked to explain why Lewis strukures are important.

Lewis Shcturea arevitallv inmortant. because thev are the . . basin for understanding how and why molecules work. By being able to draw Lewis Structures, we can predict the char- acteristics of a molecule without blindly memorizing its prop- erties. Lewis Structures provide a visible model of molecules that we as students would never be able to see otherwise. Al- though Lewis Structures are not mmpletely accurate in their representation of molecules (especially in the area of electmn sharing) they provide a useful model.

"What Would Happen M Water Were A Linear Molecule?"

In another assignment students were asked 'What if water were a linear molede?"

Under normal circumstances water is a bent molecule. It has this structure as a result of two unbonded electmn pairs, with a strong electronegativity at the oxygen end of the water mol- ecule. This negative charge attracts the H+ of other water mol- ecules and because of this strong attraction H-bonding occurs. These strong bonds in the bent molecule allow water to exist in a liquid state as opposed to a gaseous one.

However, if by chance aliens came from Mars and infiltrated our ecosystem with a "water molecule straightener" we as hu- mans would be in a bit of tmuble. If water were linear, then H-bonding wouldn't take place. All of the standing water could no longer exist in a liquid state and would, therefore, dissipate into the atmosphere. This in itself would devastate the world because the earth's water acts as a blanket keeping the tem- perature relatively even. Temperatures would then fluctuate

. . . alive, its body couldn't'adjwt ththat change and it would die. One huge problem would result because a large percentage

of our body is made up of water We could no longer exist nut only because of our environment but also because there would be nothing let% to exist.

Written Plans for Performance Improvement

Another type of exercise requires a written plan from students who do not perform well on the first test of the semester indicating how they are going to improve their performance on subsequent tests. Surprisingly, many of the students who are asked to do this are grateful thatthe faculty member is interested enough to require such work from their students.

Thank you for taking the time to speak with me about my chemistry test. It is nice to know tbat you truly care how I am doing in your class.

After your talk I went home and worked on my chemistry test. I am planningto keep up with the computer programs and do the homework problems assigned to me. If1 should have any problems, I will not hesitate to see you in your oilice. I have decided to take time out each day to work on chemistry so I will be prepared for class lecture. I know I can do well in this course, and I put my mind to it and as of now my mind is to it. Thank you again for helping me to set my goals and priorities straight.

Results In summary the benefits acmed from the writing as-

signments are as follows. 1. Student Performance. Student feedback indicates

that the writing assignments have helped them signifi- cantly in their studies. Over 90% of students indicated on an anonymous survey that they felt the writing exercises were worthwhile. Although multiple-choice testing may not be the best indicator of the benefits ofwriting, students in sections where writing was required did perform better than average on our common exams.

2. Communication. The writine assienments allow the instructor to give and receive feezhack-from all students, not iust the most vociferous. which is sometimes mite a d f i k l t task in a large enrollment course. A path df com- munication such as this is im~ortant in a situation where students may not have any pe-rsonal contact with their in- structor. Althowh the method is somewhat time consum- ing, it is no more so than grading a written problem from each of the students.

3. Student Satisfaction. Course evaluation forms indi- cate that the students are significantly more positive about the course and the instructor, when writing strate- gies such as those described are used.

4. Faculty Inuolvement. Since these types of assign- ments were first given, other Clemson chemistry faculty have observed their benefits and begun to use writing in their own courses.

Conclusion It is ~ossible to incornorate writine assienments into a

large f;eshman class. significant benkts fan be observed both to the students and the instructor, resulting in better student performance and satisfaction with the course, in- creased communication in both directions. and more fac- ulty involvement with the students.

Literature Cited 1. Zinser, W. Weling f o h m ; Harper and Row: NewYmk, 1988. 2. Van Ordern, N. J. Chem. Educ. 1987, M, 506. a. Straus, M. J.; Nai1er.T. J. Cdl. Sei. lbching 1987,16,256. 4. BeaU.H.' Chem.Educ. 1881,66,148. 5. Benaware, C. A,; De".E. L.Am Educ. Res. J 188(,21(41.755

Volume 70 Number 6 June 1993 4?7