PLACEMENT Ln BEGINNING CHEMISTRY COURSES at BROWN UNIVERSITY ANDREW H. MACPHAIL* AND LAURENCE S. FOSTER Brown University, Providence, Rhode Island
S
INCE 1930 some use has been made of the objective-type tests for placement purposes in the beginning courses in chemistry a t Brown University. Three courses are offered to the average entering student who is not generally qualified for advanced standing: Chemistry 1, Elementary Chemistry, a year course primarily for those who do not present chemistry for admission; Chemistry 3A, General College Chemistry, a year course for those who present chemistry for admission; and Chemistry 5, Inorganic Chemistry, a semester course open only to those registered for the degree Sc.B. in Chemistry. The placement program discussed in this paper is applied specifically only to the group who would normally register in Chemistry 3. The procedure has been found very useful, however, in determining for prospective Sc.B. candidates the advisability of their pursuing the special chemistry curriculum. Up to 1930, students who presented chemistry for admission (except Sc.B. candidates) and who wished to continue work in the subject were registered automatically in General College Chemistry. Students who did not present chemistry for admission, even though they might have had good preparation in it, were automatically registered in Elementary Chemistry. The whole procedure prior to 1930 was rather rigid, and too large a percentage of the students had serious difficulty in the General College Chemistry course. Since it did not seem advisable to lessen the rigorous nature of the course itself, as most of the students were able to profit from it, the practice was instituted of transferring the less well-aualifitd students from the (kncral Collecc Chemistry ~ & s eto the Elementary Chemistry ~ o u r s e . Some means of identifying the poorly prepared student
* Of the Department of Education in Brown University
was sought, and, beginning in the fall of 1930, the Iowa Chemistry Training Test was given early each year to all those who had studied chemistry previously, whether they presented chemistry for admission or not. On the basis of their poor showing on this single test, some students were advised to transfer to the Elementary Chemistry Course. The procedure was haphazard, and to improve the technic, the predictive value of scores on this test was made a subject of study for several years. Other indices that might have a bearing upon placement in chemistry were included. As a consequence of these studies, more formal placement procedures, based upon adequate data, have been devised. In the fall of 1935, the General College Chemistry course was modified rather considerably so as to minimize the amount of material presented which duplicated that usually included in the secondary school course. Cartledge's "Introduction to Inorganic Chemistry,"t and the accompanying laboratory manual,? were adopted as textbooks. An extensive bibliography for outside reading was prepared, and a problem syllabus was written to augment the text in places where the instructor felt that the students could profitably follow a more arithmetical approach. It was soon apparent that while the newly organized course was more stimulating and profitable for the well-qualified and superior students, those of low aptitude obtained less from i t than from the former more conventional descriptive course. The need for a reasonably good method of measuring the aptitude of the entering students who have studied chemistry previously, to be applied before actual registration, became even more pressing.
t Both published by Ginn and Co., Boston, Mass, 1935.
The search for a satisfactory selective procedure involved a study of the predictive values of several factors.* Data based on the three entering classes in 1933, 1934, and 1935 were used and included all cases (A' = 179) for whom all of the following measures were available. First semester grade in General College Chemistry. Iowa Chemistry Training Test, Series CT-1, Revised B.t Part 11, Mathematics Section, Sones-Harry HighSchool Achievement Test.$ Brown University Psychological Examination.$ Rank in secondary school class (on a sigma scale).
t Published by The Bureau of Educational Research and Service, Extension Division, The State University of Iowa, Iowa City, Iowa. $ Published by The World Book Company, Yonkers-on-Hudson, New York. (Also Boston, Mass.) 5 Published by Educational Test Bureau, Inc., 3416 Walnut Street, Philadelphia, Pa.
era1 College Chemistry grade. Of these three combinations, the one selected as best for practical use was that obtained by the best weighting and summing of the Iowa test scores and the Sones-Harry mathematics test scores. The correlation of this combination with = 0.638 and the the Chemistry Course grades was 121.~~ regression equation used was X I = 0.156 X2+ 0.253 Xa + 50.5 By means of the above regression equation, predictions of the probable grades in the first semester of General College Chemistry were made for the freshmen entering in the fall of 1936 and 1937. (The procedure Predicted General College Chemistry Grades (First Semester)
The following zero order correlations** were computed.
Several multiple correlations*t were then computed involving diierent combinations of the foregoing variables. They are arranged in descending order of magnitude of R.
20
The zero order coacients show that the scores on the Iowa Chemistry Training Test and the Mathematics Test correlate distinctly better with the General College Chemistry first semester grades than the psychological test scores do or the relative rank in the secondary school class. Of the six combinations of predictive criteria that were evaluated, only three produced multiple correlation coefficients higher than 0.56, the coefficient between the Iowa test scores and the Gen-
30 40 50 60 70 80 Sones-Harry Mathematics Test FIOUREI.--C~APHICAL SOLUTION 0s REGRESSION EQUATION USED IN PREDICTING PROBABLE GRADES, ON THE BASIS oa THE IOWACHEMISTRY TRAINING TEST SCORESAND THE SONES-HARRY MATHEMATICS TEST
SCORES
was used as well in the fall of 1938,but the course grades were not available when this paper was written.) In general, those for whom a grade of C+ or better was predicted were advised to register, as had been the usual case, in General College Chemistry. Those whose predicted grades were C- or lower, were advised to take * An explanation of the typical steps involved in such a study Elementary Chemistry, even though the majority had as this will be found in Chapters 4 and 5 of H. E. Garrett's "Sta- presented a unit of chemistry for admission. A few tistics in Psychology and Education," Longmans, Green & Co., New Yark City, 1926. We are not aware of any published de- students who had studied chemistry previously but had scription of how to derive the particular form of chart, based not presented it for entrance credit showed themselves upon the regression equation, used in the predictions. Its essen- to be well qualified to register in the more advanced tial nature is that of a iomograph. **The zero order correlation, 71. represents a correlation course. At the time of registration the cases of students between two items only; in this case, items 1 and 2 of the five for whom C- was predicted were frequently given addimeasures used. *t The multiple correlation, Rl.,sr, represents a correlation tional consideration in the light of any added informabetween item 1 and items 2, 3, and 4 taken simultaneously. tion which seemed to have bearing on the probable
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quality of their work, and shifts from one course to the other were permitted whenever it seemed advisable. In the actual work of making a prediction for a given student, his two test scores could be substituted in the regression equation given above. This would be a slow process and might delay actual placement beyond a practical date from an administrative and educational point of view. To facilitate the making of predictions a chart (Figure 1) was constructed which, in graphic form, constitutes the solution of the equation for all substitutions that would be practical. The diagonals in the chart were determined by holding two variables constant and solving for the third. For example, with the course grade held a t 70 per cent. (the lower limit of C-) and the Iowa score a t 20, the
kind is drawn on cross-section paper, numerical grade predictions can be made, hut if the interest is confined to letter-grade predictions, location within a certain area is adequate. For example, a letter grade of A - is predicted by means of the chart for a student who scores 140 on the Iowa test and 75 on the mathematics test. A second chart based on the multiple correlation between the psychological test scores, the Iowa test scores and the General College Chemistry first semester grades was constructed (Figure 2). The two charts were used in the placement program in 1936,1937 and 1938. The particular chart used in any given case was determined by the nature of availahle scores. However, preference was given to Chart I whenever a choice was possible. The procedure is easy to administer, since the collection of data and the recording of the grade-predictions Predicted General College Chemistry may be carried out by clerks in the college admissions Grades (First Semester) office. If the aptitude and training tests are given prior to the formal opening of college, the predictions are availahle to the registration officer and may be used most profitably in determining a t the time of registration which of the courses the student should enter. The confusion attending changes in registration after the beginning of classes is eliminated. The chief advantage of the prediction charts is that they take into account factors other than the retention of a considerable amount of secondary-school chemistry. Occasionally a bright student who has had only a very meager school course in chemistry, and does not show up well on the Iowa Chemistry Training Test, has very high scientific aptitude. He may do very well on the other measuring devices and be selected for the more advanced group. The procedure, in addition, is of such general applicability that i t can be adapted to whatever changes in course administration are deemed desirable. Two checks have been made in an attempt to measure the effectiveness of placements.made primarily by the use of the prediction charts. The first was a correlation of predicted grades and obtained grades in the General College Course. It proved to be high, showing that the scheme works out with the degree of success that was 30 40 50 60 70 80 expected from the regression equation used, although Brown University Psychological the obtained grade is for the whole year and the preExamination diction was for only the first half year (since the original FIGURE ~.-GRAPH~CAL SOLUTION ow REGRESSION EQUA- data were limited to the first semester grades). The TION USED M PREDICTING PROBABLE GRADES, ON THE BASIS oa TEE IOWA CHEMISTRY TRAINING TESTSCORES second check was obtained by studying the scores on AND THE BROWNUNIVERSITY PSYCHOLOGICAL EXAMINA- the Cooperative Chemistry Tests,* which were given TION SCORES near the end of the school-year in both 1936-37 and 1937-38 to all the students registered in General College Chemistry and Elementary Chemistry. The recmathematics score would have to be 64.8; with the ords selected for comparison were those made by the grade a t 70 per cent. once more, but with the Iowa score entire group of students in the General College Chema t 40, the mathematics score would have to be only 52.5. istry Course and those made by the group of students The two mathematics score values of 64.8 and 52.5 were who, although they had studied chemistry previously, plotted, and a line drawn through them, determining prior to entering college, were advised to register in the lower limit of the letter grade C- on the chart. By such a process the upper and lower limits of all the * Caiiperative Test Service, New York City. In May, 1937, letter-grade "zones" were located. If a chart of this Form C (1937) was used and in May, 1938, Form C (1938).
Elementary Chemistry because of low aptitude or poor preparation. The Cooperative Tests, i t should be borne in mind, are designed for the more conventional and average course, like the Elementary Chemistry, rather than the novel General Course. Nevertheless, the performance of the students in the latter course was markedly superior in each year. The critical ratio, obtained by dividing the difference between the two mean test scores for the Elementary and General College groups by the P. E. (probable error) of the difference, was about 8.0 for each year. Ordinarily a critical ratio of 4.0 is accepted as evidence of a difference of significant magnitude. The data are given in Table 1. TABLE I
Num6" Dorc of Ckcmisrrr icrl courrc May, 1937 Advanced Elementary May, 1938 Advanced Elementary
Test Srmcs'
of roses High
63 25 67 41
156 142 167 95
Law 63 65 39 24
Differcncc P.E. Cliliof Differ- col M c o d mean enrc ralia 115.6 88.2 91.9 69.6
- - 3.6 7.6 - - -
27.4 22.3
2.7
8.3
The scores for 1937 should not he cqmpared with those of 1938, since different tests were used. b The national means for the two tests were: 1937-mean for 162 colleges (9504 cases) = 94.9 193&mean for 149 colleges (9542 cases) = 73.9 DISCUSSION
The plan of using the prediction charts as the chief guide in advising entering students as to which chemistry course they should take is qualitatively very effective. The number of failures in the General College Chemistry course has dropped to a very low value and about ninety per cent. of the students receive grades of A , B, or C, where C represents officially a numerical grade of 70-79 per cent. These grades are not out of line with the grades the same students re-
(1)
CORNOO, J. AND G . D. STODDARD, "Predicting perfomEDUC., 3, 1412 (Dee., ance in chemistry, 11," J. CHEM. 19%) A"-",.
0.M. AND H. M. TRIMBLE, "Prediction of future ~erfomanceof students from Dast record." ibid... 6. 93 (1929). (3) BIRD,K. L., "Use of an aptitude test as a basis for sectioning freshman college students," ibid., 7, 1118 (1930). 14) M. F.. "Further studies an sectioninr in een-l ~ -SCORIELD. , chemisiry," ibid., 7, 117 (1930). G . A,, "An analysis of freshman college grades (5) HERRMANN, with reference to previous study of chemistry," ibid., 8,
(2)
SMITH,
.
- -
127fi (1931,. ~ -.--, ~
(6) WEST,G . A,, "InIluence of high school science on grades in college chemistry," Sch. Sn'. Math., 32, 911 (1932).
ceive in other courses in college, and when compared objectively with the grades received by the entire group of students in the Elementary Chemistry Course, on a test like the Cooperative Chemistry Test just discussed, i t is apparent that the standards are actually somewhat higher in the General Course. Furthermore, those who are advised to transfer to the Elementary Course, on the basis of the prediction charts, do not in general rise above the median of that class. But they do not so often fail, as many most assuredly would have if they had remained in the General College Chemistry Course. It seems reasonable to believe that relief from too difficult a task with its attendant worry has a salutary effect upon their work in other courses as well. Another great advantage which has been gained, obviously, is that the superior student makes better progress in the more advanced course, due to the absence of slow, inferior, or inadequately prepared classmates. The placement program is flexible, as it permits the student to use his judgment, after consultation with the registration officer, as to the best course for his particular needs. The practice of using the information and the prediction charts as a basis for advising students, rather than as a rigid criterion for registration, puts the responsibility on the student. Surprisingly few question the validity of the predictions. Thus far, this particular technic has effected decidedly better placement than existed before i t was tried, and naturally the next step will be that of re-evaluating the predictive data to maintain what has been gained and to seek improvement. Whiie the placement procedure was developed independently, the authors have, of course, been influenced by the discussions of similar procedures which have appeared in THISJOURNAL and other sources. A bibliography is appended for the benefit of those who may wish to investigate the merits of other solutions of the placement problem, but no claim is made for its completeness.
in high school." Sch. Reu., 41,40 (1933). (8) GLASOE,P. M., "Residue of high school knowledge utilizaEDUC., 10, 571 (Sept., ble in college chemistry,"J. CHEM. 1933). DAY,J. E., "University recognition of proficiency in highschool chemistry," ibid., 12, 166 (1935). FERNELIUS, W. C., L. L. QUILL, AND w. L. EVANS, "EXoeriences teachinz ~roficiencvstudents in chemistrv." .. .;bid., 14, 427 (1937): HENDRICKS, B. C. AND F. P. FRUTCHEY, ''Uses of examinations," ibid., 15, 237 (1938). CLARK, P. E., "The effect of high school chemistry on achievement in beginning college chemistry,"ibid.,15,285 (1938). , ,
