Marjorie H. Andrews and Lester Andrews University of Virglnia Charlonesviile. 2 2 9 0 1
First-Year Chemistry Grades and SAT Math Scores
Two common and easily accessible measures of university student ability are SAT mathematics aptitude test score and high school GPA. We wished to see if any predictive relatinnshins linked these two factors and final grades in freshman chemistry. We obtained the SAT math s&res, high school GPAs. and final chemistrv. -grades for both 1972 and 1976 fall semester classes of the honors and majors first-year chemistry course a t the Universitv of Virginia. This course covers 90% of Chapters 1-8 from aha an's-“~niversit~ Chemistry" and emphasizes chemistry as the understanding of basic concepts and the solution of quantitative problems under a time limit. Other chemistrv courses are available for pre-medical, engineering, and liberal arts students. A multivariate linear regression analysis was used, with consistency of the predictive functions indicated when the analysis revealed no significant changes over time.' Also, no significant differences in predictive functions were found to he due to the sex of the student. The data from both years was then combined and used to study possible predictive relationships among SAT math aptitude scores, high school GPAs, and final chemistrv. grades. . SA'I' math in)rttwas i w n d to have a much more direct reI:1ti(,114hio with final grade than did high schoul GI'A; for thnt reason hjgh school GPA was then dripped from the study. T h e complete final grade proportions, with corresponding mean SAT score and SAT range for each grade level, are given in the table. Overall grade average, axerage SAT, and total SAT score range are also shown. Figure 1shows the distribution of student grades over the four grade levels and 5 SAT ranges. Figure 2 shows the mean SAT score and upper and -~~ " lower limits for each grade level, plus the overall SATmean score and the Colle~eof Arts and Sciences average SAT math score. The relationship between the means of the different
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Figure 2. General relationship between SAT math scores and chemistry grade levels. Mean (0) and actual upper and lower limit SAT math scwes (X) are indicated for each grade level. The "m" denotes average SAT math score for students in this chemishy course: "s" indicates average SAT math score for first year College of Arts and Sciences students.
Flnal Grade Distrlbutlon, SAT Means, and SAT Ranges Grade Category
Percent of Students
25 38 28 9 C+ (average grade) Number of Students: 138 A B C DF All Students
SAT Mean 735 711 689 648 705.
SAT Range 620-800 600-800 570-760 540-730 540-800
Calculated horn original data
grade groups is approximately linear. A positive linear relationship exists; the average student grade increases as the average SAT score increases. T h e mean SAT for all students in this study, 705, predicts an average grade of C+; the actual average grade is 2.68 or a C+. T h e D F group is an exception to the general trend. ~ h i s " s ~ ~ - g r relationship ade could be used to predict limits or cut-off SAT scores for different grade levels. Students with SAT scores under 600 will prohabl{do very poorly; those with SAT scores in the range from 600-650 will probably not do above average work. In the middle of the SAT range, 650-750, anv individual erade medictions would have a great deal of uncertainty. ~okever,'atthe upper extreme of the SAT range, predictions of final grade could again be made more confidently; students with SATs above 750 who are doing poorly are probably having nonacademic problems. Other studies involving possible relationships between SAT scores and freshman chemistry grades have been reported recentlv. Pedersen reoorted that the functional relationship between average graie in freshman chemistry and average SAT cateeorv .~ also found .. . was reeular and m o n t o n i ~Pickering a linear relationship between averagt SAT math scores nnd final grades in the lirst-yvar chemistry course at Columbia:' ~~
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SCORE
RANGES
Figure 1. Distribution of grades over SAT score ranges. Students in each grade level are grouped by SAT math score.
The computer program used in this analysis was developed by Dr. M. Jacobson, Department of Research Methodology, University of Virginia, Charlottesville.Virginia. Pedersen, L., Educ. and Psyc. Meosur., 35,509 (1975). Tiekering, M., J. CHEM. EDUC., 52,512 (1915). Volume 56, Number 4, April 1979 / 231
However, he did not claim that an individual student's grade could be predicted from his SAT score, especially for the higher SAT score^.^ This study led to a similar ronrlusion. It was almost impossible to predict any student'&first semester grade when his SKI' math score was within 1 standard deviation of the overdl group mean SAT. (Overall mean 705, standard deviation 53, range f1standard deviation 652-758.) More reliable estimates of l;rol,able grade could lw made for corresponding SA'I' math srores ub(we or below this ranae. On the lower eud nt the distribution, SAT score limits for enrollment could he estahlished. A high math SAT was not a euarantee of a good erade. . hut a low math SAT was a strongindicator of alow grade, particularly with the very low SAT scores. Considering the a h w e findings, it then hecame of interest 10 investigate the secondsemester final grades in this sitme first-vear chemistrv course to see (1)if there were a simificant number of grade fluctuations frdm first to second semester and also (2) to see what sort of relationship might exist hetween the SAT math aptitude scores and the second semester final grades. Data was obtained from the same honors-majors first year chemistry course. Mahan's "University Chemistry" was the text, with the spring semester covering Chauters 9-15 and 19 and emphasizing stkcture, bonding,&d descriptive chemistry, including theoretical concepts requiring- more abstract reasoning. The possibility of a significant difference in mean student performance from fall to spring was considered using course grades for four years instead of two, all with the same professor and textbook. A paired samples t-test was done wingfirst and second semester final grades of all those students who had comuleted both semesters. Mean soring semester erade was . found to be significantly lower than the mean fall grade, with alpha > 0.01. These fall to surina erade chances - occurred mainly a t the B and C grade levels. Possible predictive relationships between SAT math scores
232 1 Journal of Chemical Education
and final grades for the 1973 and 1977 spring semesters were considered, as was done earlier for the corresponding fall semesters, 1972 and 1976, of the same classes. The SAT math aptitude scores were again found to he predictive of average final grade, with a stronger predictive relationship existing a t the upper end of the SAT distribution. For example, 47% of those students with SATs of 750 or hieher made A's: 33% made B's. Of those students in the SAT ;ore range 700-749, 77% made either B's or C's; only 21% made A's. Also in the 650-699 SAT group, grades were mainly B's and C's. Of this group, 76% made either B's or C's, with onlv 21% makine A's. As might be expected intuitively, there were fewer low grades in the spring semester; one might assume that many of those students with lower fall grades would have dropped out. Thus, for the second semester one could predict fairly confidently that students with SAT scores of 750 or ahove would make A's or B's; students in the range 650-749 would more likely make B's or C's. Students with SATs under 650 would orohahlv make C's, although there were really too few studenis in this range to make reliable predictions. This predictive relationship was similar to the predictive relationship found to exist between first semester grades and student SAT math aptitude scores, even though the mean second semester grade was definitely lower than the mean first semester gmdt,.The consistency of the predictive function over both semesters, despite the change in overdl mean grade, apparently came from thr fact that must of thegradc changes trum first ro second iemester were ot students uith SATs in the 650-749 ranre. where indi\.idual era& nredirtions were least reliahle. ~Leielationshipbetween SAY math aptitude score and chemistry grade discussed here was consistent over two semesters covering different hut closely related suhject matter. cf. Pickering, J. CHEM. EDUC., 54,433 (1971),for a follow-up study of those high-risk students mentioned in (4).
