The EFFECT of the NATURE of the
COURSE on ACHIEVEMENT Ln FIRST-YEAR COLLEGE CHEMISTRY PAUL E. CLARK Muskingum College, New Concord, Ohio
T
HE whole subject of the improvement of science instruction a t both the high-school and the college level is now being studied vigorously by several groups as well as by many individuals. For instance, the Committee on Tests of the American Association of Physics Teachers has done much research on the effect of high-school physics on achievement in college physics. Some conclusions were given in the third annual report.' Also the Committee on Examinations and Tests of the Division of Chemical Education and the American Council on Education have been working cooperatively on the construction, distribution, and use of better tests in chemistry a t the high-school and the college level.z Several papers have been published rather recently dealing with the effects of a high-school course in chemistry on student success in beginning college chemistry. Unfortunately some of these studies were not carried out in such a manner as to enable the investigators to arrive a t valid conclusions. Other investigations have been reported in which definite attempts were made to control conditions so as to enable the investigators to identify effects associated with the taking or the not taking of high-school chemistry. Some such reports have been made by NoU3and by C l a ~ k . ~ , ~ Very little research has been reported, however, on the effect of the nature of the first-year college chemistry course on achievement in college chemistry. In many colleges all first-year chemistry students are sectioned together, regardless of previous training (or lack of it) in the subject. In other colleges some attempt is made to section students on the basis of previous train-
ing in chemistry, scores earned on chemistry aptitude tests and the like. Glasoe,'~' especially, has contended that the students who submit chemistry as an entrance credit should be given a more advanced course in first-year college chemistry than those who have had no training in chemistry. Glasoe's reasoning and conclusions seem logical. However, it appears to this writer to be a better pedagogical practice to section chemistry students on the basis of their probable chances for success in chemistry rather than merely on the basis of previous training in the subject. This would mean that most of those with high-school chemistry would go into the more advanced course but that some with high-school chemistry would be placed in the elementary course because of their probable inability to succeed in the advanced work. This is the way in which chemistry students are sectioned a t Muskingum now. Regardless of the manner in which first-year chemistry students are divided, i t seems desirable to try to determine if i t is worth while to offer two different courses in first-year college chemistry, i. e., an elementary freshman course and also an advanced freshman course. The purpose of this study was to determine if those students who took the advanced course (Chemistry 121) really achieved more than those who took the elementary course (Chemistry 111). The percentiles earned by the students a t the end of the first semester on a chemistry training tests (end-test) were used as the criteria of achievement. The study was limited to the freshmen and sophomores who had high-school chemistry credit and who took the first semester of first-year chemistry a t Muskingum College during the school vears 193536 and 1936-37. ,~~ "The 1935-36 college physics testing program," Supplement Since the purpose of the research was to try to deterto The American Pkysics Teacher. 4, 153-66 (Sept.. 1936). mine the effects of the course on achievement, i t was ' "The 193536 college chemistry testing program," J. CHEM. thought desirable to try to control other important facEouc.. 14. 229-31 IMav. 19371. N&' V. H., ;'~af&atar$ instruction in the field of in- tors in success in chemistry. It was obviously impos~~~
organic chemistry," University of Minnesota Press. Minneapolis. Minn.. 1930, pp. 104-7. WUSIUN COLLEGE G ~ FACULTY,"A college looks at its program." Muskingum College. New Concord, Ohio. 1937, pp.
". CLARK,P. E., "The effect of high-schoolchemistry E 7 2"=. A
on achieve15,285-9 ment in beginning college chemistry," J. CHEM.EDUC., (June. 1938).
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GLASOE.P. M., "Residue of high-school knowledge utilizable in college chemistry," ibid., 10, 5 7 1 4 (Sept., 1933). GLASOE.P. M.. "The chief sin in ht-vear colleee chemistrv teachinp." ;bid.. IS. 14-6 (Jan.. 1938). "Iowa Placement Examination," New Series C. T., Form X (1930) and "Iowa Placement Examination," Series C. T.I. Revised A (1925).
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sible to control all factors other than the course, so as extensive a preliminary investigation was made as possible to determine which factors should be controlled. ~ l s oi,t was known that if the most important ones were controlled, i t would be unnecessary to control the less important ones as far as practical purposes were con. . cemed. Data on the following points were available for all students involved: oercentiles earned on The Ohio State University Psychological Examination, percentiles earned on a chemistry aptitude test9 given during the firstweek of school, percentiles earned on the chemistry training test given during the first week of school (pre-test), and percentiles earned on the chemistry trainincr test piven a t the end of the semester (endtest). Those students who took Chemistry 111 were used as the control group. It was decided to devise a regression equation for the control group by means of which it would be possible to predict the percentiles which these stndents would make on the end-test and then to apply this same equation to the experimental group. The correlation coefficient between the pre-test and the end-test percentiles for the control group was found to be 0.88. This was quite high, and the use of the other factors proved not to add significantly to the accuracy of predictions based on the pre-test alone. In view of this fact, the following regression equation was developed for the thirty-nine members of the control group ~
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XI
= 0.98Xs
'+ 17.12
where XIis the percentile which the student was expected to receive on the end-test and Xa is the percentile which the same student received on the pre-test. End-test percentiles were then predicted for all members of the control group and a correlation of 0.88 was actually found between the predicted and the earned values. By means of this same regression equation the endtest oercentiles were oredicted also for those students who 'took chemistryA121. Thirty-two students who took Chemistry 121 (Gronp C) were then paired with thirty-two students who took Chemistry 111 (Group B). Both members of a given pair had the same predicted end-test percentile. Then, within the limits of error of the experimental method employed, the members of Group C should have earned the same mean percentile on the end-test as the members of Group B except for the influencing factor of the course taken in college chemistry. The mean pedicted end-test percentiles were exactly the same for the two groups; i. e., 58.9 with a standard error of 3.8. The mean earned end-test percentile for Gronp B was 59.9 4.42, but the mean earned percentile for Group C was 65.3 * 3.75. The differencehere a "Iowa Placemat Examination,'' New Series, C. A.. Form X (1930) and "Iowa Placement Examination," C. A , , Revised A
(1P25).
is 5.4 percentile with a standard error of 2.40, and this differenceis in favor of those students who took Chemistry 121-the course designed especially for them. This difference was not due to chance, for it can be shown statistically that if the experiment were repeated with similar groups and in a similar manner, the chances are 81 to 1that there would be some difference between the groups and in favor of Group C. The average gain (end-test percentile minus pre-test percentile) for the members of Gronp C was 23 percentile, while the average gain for the members of Group B 'was 18 percentile. Assuming that the gains for the members of both groups were evenly distributed over the entire semester, this indicates that in just a little more than fourteen weeks the average gain for the members of the experimental group would have been eighteen or the same as the average gain for the members of the control group in the entire semester. This is certainly a significant finding for the teachers of the courses. The conclusion which follows is inevitable; namely, that when controlled conditions were maintained, the freshmen and sophomores who took Chemistry 121 a t Muskingum during the period 1935-37 really achieved more as measured by the end-test used than those who took the more elementary course. If we assume that it is desirable to teach together students having about the same chances of success, this finding seems to indicate that the two groups should be segregated. That is, most of the stndents with high-school credit in chemistry should not be forced to take first-year college chemistry with a group of students, who, for the most part, have had no previous training in the subject. Of course, even with high-school credit for chemistry, some few students are incapable of succeeding in an advanced freshman course and probably they should be sent over into the more elementary course. At the present time a t Muskingum, all students who elect chemistry and who submit high-school credit in it are required to register for the more advanced course. Then, early in the semester, some are transferred to the more elementary course on the basis of their showing on chemistry aptitude and chemistry training tests. This practice seems satisfactory now, but the writer expects to continue to evaluate and to adjust the procedure as conditions seem to warrant. Perhaps the reader should be cautioned against indiscriminately applying the above conclusions to other groups of students. The results cited are based on statistical concepts. If other students were used, if different criteria of success were used, and if different methods of carrying out the investigation were employed, somewhat different results might be obtained. Nevertheless, the results have helped the members of the chemistry staff a t Muskingum in their attempts to secure more nearly homogeneous groups in the two firstyear courses. It is hoped that this paper may also serve to remind chemistry teachers of the applications of the well-known experimental method to problems of an educational nature.
