Contributed Papers: Session C Rapporteur: 0 . Seely, Jr., California State College, Dominguez Hills
The topics presented in this session can be divided into three catkgoriks: the selection and placement of students according to aptitude and background, modification of the learning-environment, and the presentation of chemical concepts to nonscience majors in a manner compatible with their interests. Paula Pimlott Brownlee (Douglass College, Rutgers University) descrihed a program designed to identify and help entering students who do not have the developed abilities essential to success in the first college chemistry course. A 30-min analytical reasoning test containing questions requiring six different mental abilities (algebra, graphs, variables versus constants, spatial relationships, ahility to discriminate between relevant and irrelevant data, recognition of physical laws) was administered to the entire entering freshman class. Those students who were unable to answer correctly four or more questions were encouraged to enroll in a special developmental course instead of the regular general chemistry course. The students who most needed the help available in the developmental course were alened early-!)). the use of this test, alrhough many students needing help \r,ere relurtant to enroll in-a noncredit course on the basis of the results of a single 30-min test. The author displayed data containing a tabulation of average scores on the analytical reasoning test and the mean general chemistry grade. Generally, the higher score a student had on the reasoning test, the higher was her or his mean general chemistry grade. The author felt, however, that there is still a great deal of intimidation associated with a 30-min examination of this kind and that an alternate means should be found for selecting the students for developmental assistance. Two possibilities suggested by her were personal interviews and the use of computer assisted instruction to pinpoint each student's weak areas. A description of the preliminary course for underprepared college chemistry Htudents was given by JosephM. Most (Upsala College). The principal object of the course is to motivate students to deal with problems in scientific ways. Positive student acceptance of the value of the course has been shown by a doubling of the enrollment during the past two years. The students enrolled in the preliminary course came from a wide variety of backgrounds: students with undistinguished high school performances, students with good high school grades who claimed that these grades merely reflected their performances in courses of poor quality, and those having been away from the classroom for a number of years, including veterans and housewives. Throughout the course, emphasis was placed on the scientific approach rather than on the details of chemical science. For example, the first assignment directed the students to choose some well-known advertisement or commercial and outline a procedure for testing its claims. Such assignments greatly stimulated class participation and caused students to face each prohlem a t hand thoughtfully. Methods of measurement, a study of the metric system, significant figures, accuracy, and precision were also important parts of the course. The use of common objects to emphasize metric units was felt to he a valuable approach in gaining enthusiastic acceptance of the material. Of the 39 students who completed the preparatory course in the Fall of 1972, 24 went on to complete the first semester of General Chemistry during the following Spring semester. From the data presented during the talk, it was evident that the preparatory course 24
/ Journal of Chemical Education
served two purposes. First i t allowed students with high ahility hut poor background to rise to a higher competitive level before taking chemistry for credit. Secondly, it discouraged a sizeable fraction of students having fpresumahly) low ahility from taking the general chemistry course, thus ensuring higher standards in the credit course than would otherwise have been realized. An experiment in science teaching was described by Thomas E. Taylor (Universidad de las Americas). The experiment was an attempt to incorporate the following elements of oiu psychological knowledge of entering university level students into a viable teaching program for large numbers of students a t schools with limited budgets: (1) Virtually all of our students are more than capable of attaining mastery of the subject matter in their introductory courses. (2) What we have classically dubbed bright (or dull) students should more aptly he referred to in terms of hours of work required to attain a given objective. (3) No correlation has been found between rapidity of learning and ahility to master new material. (4) No correlation has been found between rapidity of learning and retention. (5) Retention is improved by an inductive rather than a deductive approach. (6)Classroom attention is of short duration. (7) Lack of motivation is the major ohstacle to performance. (8) Success inspires students and failure or frustration leads to withdrawal (and ultimately to antagonism). The number of full class meetings was reduced from five hours per week to one hour per week. Behavioral objectives and a variety of audio-visual devices were used throughout. A device of major importance was a specially designed study room containing chemicals, laboratory equipment, study desks seating a maximum of three students each, audio visual material, answer sheets and problem solutions, and an ever-present instructor (or one of his assistants). A student would work in this room until she or he had mastered each behavioral objective. The hours per week required for mastery differed greatly from one student to another as well as with the material covered. A joint contract between professor and student was signed a t the beginning of the term. The student agreed to master each portion of the material of the course; the professor agreed to provide help as long as the student fulfills his or her study obligations. A student failing to fulfill the contract was immediately eliminated from the class. One full-class meeting was held each week. The professor put on a genuine "show" for motivational purposes, using examples of applications of the current topicfs) in both industry and research and emphasizing the importance of each area to contemporary scientists by describing recent discoveries whenever possible. Approximately half of this weekly class session was devoted to this "show." The remaining time was spent in discussing the behavioral objectives for the subject matter of the following week. The students taking part in this experiment were administered an American Chemical Society General Chemistry Examination (form 1968) at the conclusion of the course. Forty-two percent of the students placed in the 99th percentile according to the test norms. One hundred twenty-six students began the course; one hundred nineteen finished it successfully. A program of individualized instruction in organic chemistry was described by Robert H. Garner (University of Alabama). As in the case of the Taylor experiment,
the number of lectures each week was reduced and replaced by nine hours of open class or laboratory. Students were given the freedom to choose which experiments to do and when to carry them out. Students were guided through the course with behavioral objectives and progress was monitored by administering ten basic unit exams and six optional exams. Students were allowed to repeat exams up to three times until a minimum of 80% on each was achieved. Course arades were based upon class and laboratory work satisfactory completed. Tentative conclusions include observations that the experimental section achieved positive results in improving student effort and sustaining student interest and stimulated innovation by the staff in other instructional efforts. Although the retention of course material was nearly the same for the experimental section and the rest of the class, the relationship of this to cost-benefit factors has not been fully analyzed. Finally, in a colorful variation on the theme of the session, Treva Pamer (Jersey City State College) described an approach to teaching transition metal chemistry to nonscience majors using examples drawn from the field of art materials. Solutions of transition metals in glass con-
stitute one of the major types of glass and ceramic glaze colorants. The elements cobalt, iron, and copper are used in this course to illustrate the principal variables which affect color: oxidation states of the metal ion, coordination number, and the acid-base balance of the glass. Cobalt illustrates variable coordination number, producing a deep blue when coordination is four-fold and pink when coordination is six-fold. Iron exhibits color changes with variable oxidation number. Ferric ion produces a dull red as can be observed in many clay products. The reduced states of iron can he achieved using special firing conditions. The Chinese celadons owe their pale green to ferrous ion, and the black of Greek vases is due to the presence of Fe30r. Copper in the cupric state illustrates the effect of acid-base balance. Most formulations yield a weak turquoise analogous to that of common cupric salts in dilute solution. Strongly alkaline glazes of the ancient Egyptians produced a deep blue similar to that of cupric tetramine complex. In lead-based glazes, cupric ion exhihits a green similar to that produced by heating or concentrating cupric chloride solutions.
Volume 52. Number
1, January 1975
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