A general chemistry course for science and engineering majors with

A General Chemistry Course for Science and Engineering. Majors with ... one-credit laboratory course is required of all students in ... course. Most s...
0 downloads 16 Views 3MB Size
A General Chemistry Course for Science and Engineering Majors with Marginal Academic Preparation Leonard S. Kogut Penn State University, Beaver Campus, Brodhead Road, Monaca, PA 15061 P e m State administers placement tests to incomingstudents in algebra, Enplish, and chemistw and places high.. .. risk students pursuing sclence and e n e n w r i n g into a course that runs parallel to thc normal three-credit (Chem 012) chemistry lecture. At Penn State Beaver Campus, the course that accommodates these inadequately prepared students is CHEM 017, a five-credit course. A separate one-credit laboratory course is required of all students in CHEM 012 or CHEM 017. I have taught CHEM 017 for 10 years. I n this paper, I share suggestions and strategies that I have developed for helping students during these years, and I describe the course a s taught during the 15week Fall 1990 semester. ~

Description of the Course Both CHEM 017 and CHEM 012 cover the syllabus typical of most introductory courses for students in science and engineering and the same textbook, CHEMISTRE: (Mortimer, 6th ed.) was used in both courses. CHEM 017 with 47 students Der section met for two 75-minute (T-Thl - - -. and two 50-minu& (M-W) class periods per week. CHEM 012 with 82 students oer section met for three 50-minute periods in a week. Instructors at other Penn State locations use the extra 100 minutes of class time in a variety of ways including introduction to laboratory skills, concentration on mathematical skills early in the semester with a n accelerated pace later, and regular recitation or review. I use the additional course time in a flexible manner and plan class activities on a weekly cycle. By using feedback such a s student performance on quizzes and responses to in-class questions, I adjust the pace and sequencing of course activities (lecture and recitation).

Description of the Students Table 1 resents data describing the academic abilitv of the Fall i990 sections of C h e r n & y 17 (5 credits) A d Chemistry 12 (3 credits). Although the average SAT verbal score is somewhat higher for the students assigned to Chemistry 17, it is clear that these students have lower algebra and chemistry ability thanthe Chemistry 12 group based on the pre-entry placement comparisons. The m a x -

Table 1. Academic Ability Chemistry 12 (n = 82)

Chemistry 17 ( n = 47)

Math SAT Average

534

499

Verbal SAT Average

427

441

Algebra Placement Average

20.7

14.5

Chemistry Placement Average

10.1

5.3

English Placement Average

27.1

27.2

Fall 1990 QPAin Chemistry

2.54

2.45

mum grades i n algebra and chemistry are 30 and 20, respectively. Chem 17 students are poorly prepared for chemistry. I have experientially classified my observations based on my encounters with these students over the years into four categories of "difficulties". S o m e of the students have inadequate mathematical skills to cope with the course. These skills include using logarithms, performingcalculations, using exponential notation, and analyzing and usingunits in dimensional analysis. Many students lack the study skills needed to succeed in this course. Most students enter the course and college with an unrealistic set of expeetations concerning their individual abilities, and the time-commitmentsthat they must make to achieve satisfactoryperformance at the college level. When asked to predict their expected grade as part of a course evaluation instrument, 80% of the students in Chemistry 17 predicted A or B. The majority of these students also indicated that they planned to study a total of 6-10 hours per week on all subjects! Many students are un~racticedand. therefore. unskilled in critical thinkinewhiehieauires them to aonlv . . .basic eonce~ts to problems in which morc than onechrmical principle must hr npplicd.They generally score much lnwsr on test or homework pmblrms rrquiring inte~ationoftwo or mure concepts than on a single concept problem ~~

~~~

.~ ~~

Chem 17 cannot solve or overcome all of these difficulties. Not all students suffer from all of these maladies. and not all students suffer from a given malady to the same degree. I do intend for Chemistry 17 to provide instruction that will assist students to overcome each of these difficulties.

Goals for Chemistry 17 Related to the problems encountered by students are several goals t h a t 1 seek to achieve in tea&ing the course. Some of these are consistent with the apprt~uchdescribed by Turner ( 1 ) in her report of a supplemintul course to improve performance in General Chemistry. Unlike Turner, I incorporate my methods into the body of the course. hat students must be able to learn and apply a s many chemical principles a s possible (the set of course learning objectives) is.ohvinns~ . . - ... I believe I inherit other obligations, because of the nature of the students and these obligations become the penera1 goals for the course: h have positive impact on general study skills and study skills specific to chemistm.

To emphasize to students the correlation between time on a task and success. hprovide early and frequent performanceappraisals of student work. .To demonstrate often how a chemist solves problems and thinks about course-related ~rohlemsvia in-class exercises. 'To prwlde frequent in-classupportunity For students u, practire prohem-solmng and rrirlral thmking. .To mrroduer student* t o pmhlcms in which they must describe their reasoning in selecting correct soluti6ns as well as in discarding incorrect solutions.

Volume 70 Number 7 July 1993

565

h cmesent information lectures in ~ -~ ~ ~ ~durine ~

chunks that are palatable ta students both in &tent and length. To assess course progress and update the schedulein class at least once each week. To keep the burden of responsibility for learning in the hands of the students. To provide a variety of learning modes and to increase the opportunity for students to learn. ~

All of the above support a trancendent goal-to retain students in the sciences. Tobias (2)cites some of the reasons for the loss of science students and urges us to think about "Who doesn't do science and why not?" In Chemistry 17, I hope to provide some students-who might otherwise opt out of science-the skills and interest to, at least, give science a chance. Strategies for Teaching Underprepared Students In order to attain the general goals described above and to meet the needs of students in Chemistry 17, I developed the following strategies and used each during the Fall 1990 semester of Chemistry 17. Frequent Testing

Eight quizzes (1.520 min duration), three examinations during the semester (75-minduration) and a 120-mincomorehensive final comorised the testine. Quizzes were ~ r i karily problem-orienied and often reLted to the previous homework assienment. The semester exams were approximately 40% mktiple choice (20 questions) and 60% pmblem-oriented (5-7 auestions). I returned and discussed all quizzes and examsbn the class day immediately after the testing took place. In addition, one take-home quiz requiring analysis of a problem (critical-thinking) was assigned and the grade substituted for the lowest extant quiz grade. Frequent Practice

Opportunities to practice problem solving, test assumptions, make-errors, and work with other students in a nonthreatening environment were provided via work sessions in class and review sessions prior to class. Students were called on to answer soecific auestions on homework moblems as well as in-class prodlems. I also encouraged students to ask auestions. especiallv during a period set aside a t the beginning of each class. My refor that sponses to "wrong" answers were positive and encouraging, and I made a concerted effort to create a comfortable environment for student-instructor exchanges early in the course. Although the beginning of class was the formal question period, students could ask questions a t any time during class, whether the format for the day was review, discussion, or lecture. Extra Review Periods

After the second week of the course, I collected student schedules and arranged four optional review periods each week outside of normal class times. All students were able to attend a t least two of these if they so chose. Two periods preceded the normal 9:30 a.m. start of class on Tuesday and Thursday by 30 minutes. The other two took place on Mondav afternoon and Tuesday immediately aRer the regular class that day. Student attendance was good and aimost every student attended a t least one review period during the semester. Approximately 30% of the students participated steadily in two review periods per week. One student attended all of the review periods! I primarily answered student questions during these extra sessions and occasionally posed a problem for the group related to a topic that had been introduced by a previous student question. 566

Journal of Chemical Education

Mock Examinations

I administered an in-class mock examination of similar format, length, and degree of difficulty to each in-semester exam a week before the actual exam. I allowed students to substitute the mock exam grade for the grade on the actual exam if the former were hizher. Although several students actually performed better on the mockexam, the average scores typically were lower than the respective actual exam by 10 to 15 points. All exams were valued at 100 points. These mock exams bridged the gap between unrealistic student self-assessment of preparedness and the level of difficulty of the material. Library Reference Folder

The campus library maintained three identical course folders for all quiz and exam answers, sample exams, detailed solutions to homework assignments, and course lecture notes taken by two students whom I assigned to this task based on their performance on quizzes and their attendance. Availability of accurate and complete notes can assist students who are poor notetakers and adheres to the report by Streitberger that college students recommend to high school students enrolling in college chemistry that they learn how to take better notes (3). Cognitive Frameworking

I began each lecture session with a brief outline, usually a tree diamam on the chakboard, of that day's activities and majortopics. I related new concepts to each other and to both previous and forthcoming topics. The tree diagrams s&ed as mad maps of proGessdunnga particular lecture and each new concept was labelled with its learnin@obiective and location in the textbook. I used the textbo;k frequently during class and advised students to bring it with them. I never lectured for more than 20 minutes without a pause, abrupt change, or example to allow students time to process the information and ask questions before beginning the next topic or concept. Promotion ofActive Learning

Questions asked of students during class were one form of active-learning. I typically asked four to six questions oer lecture oeriod and more durine reviews. I alwavs aliowed time for student responses-ui to 15 seconds-agd required students to explain all answers, correct or incorrect, in order to demonstrate and cultivate critical thinking skills. Each student in the course resoonded to at least two or three questions during the semestkr. Student responses also omvided me with assessments of mv instructional effectiGeness. I used questions addressed tb the class in general as often as possible. To introduce oxidation and reduction, for exampie, I wrote six chemical reactions on the board and asked the class to identify those that exemplified oxidation-reduction. Such exercises also were used after I completed a specific topic or chapter. Keeping a Positive Attitude Poorly prepared students might feel a stigma associated with having been labelled "remedial". I attempted to pmvide this class with a comfortable learning environment and to focus on student success instead of failure. A student with a 60% quiz score has done something correctly! Early quizzes with positive feedback in the form of comments served to accentuate the positive. I reinforced the perception that I care about students by kequently writing positive comments on quizzes and exams as I graded. I returned quizzes and exams to students as they entered class. I also learned the names of each student as early in

the semester as possible and always called on individuals by name. Year

Testing Communication

Although I expected students to assume the responsibilitv for learnine. I was res~onsiblefor checkine communicaprepbed students do not receive the t i n . Many message the first time. This behavior encomnasses both course-concepts and items of a general housekeeping nature. I used the course learnine obiectives as the blanket to respond to the annoying qne&on" of 'What do we need to know?" Almost daily, I asked such in-class questions of students as When is the next auiz?" "What chapters appear on the next exam?" "Whatis the last item you have in your notes from yesterday?" Before students can learn, they need to know when, where, and how to learn. Because I said something once, I could not assume students heard or. if thev heard. that they listened. To insure that students prepared fir the final examination (30% of the total grade) I gave each student a memo with a list of study strategies for the final, a statement of the importance and utility (for cementing information and establishing connectionsamong concepts)of this exam, and a list of chapter sub-headings in the text and learning objectives that were to be covered. As an experiment I allowed students to bring to the exam an 8 112 k 11sheet of paper with any inform-ation they chose to fit on both sides. I collected and analyzed these and determined that 26 of the 46 sheets turned in contained information directly related to excluded topics and many of these sheets contained several sections of extraneous information on which the students presumably had spent time studying. I attribute much or this behavior to poor commu~cation.Some underprepared students apparently lack the metacognitive skills needed to do well in chemistry and many other college courses. Evaluation

Students in Chemistry 17 and 12 have not taken a common final examination for reasons beyond the mntrol of the author. However, some students in both murses were required by their choice of major to enroll in the sewnd half of General Chemistry, Chemistry 13. Table 2 provides grade distributions for Chemistry 13 for the years 19871990 as well as for 1991 when all of the course strateeies described in this paper were employed. Students from Chemistrv 17 (Fall 1990, oerformed s i c nificantly better in chem