March, 1923
INDUSTRIAL A N D ENGINEERING CHEMISTRY
lated agricultural region has only remote markets for its produce. The development of both side by side is thus equally important to both. This is the direction in which the age-old issue of smeltersmoke injury is moving in this country. There are very few, if any, outstanding cases of progressive economic injury that are yet unsettled or not on the road to settlement. This has come about not always through a sheer desire to avoid doing
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injury to adjacent interests. A more important factor has been a better control of plant operation, more attention to stack losses, new markets for by-products, and less of single-mindedness in management, The old period which refused to recognize the interests either of the community or of the nation could not endure. The age of by-products has begun, tardily but truly, in America, and this means not only industrial independence, but national progress in the years to come.
An Experience with the General Intelligence Test in Teaching Freshmen Chemistry’ By Jacob Cornog and Edward Bartow STATE UNIVERSITYOF IOWA, IOWA CITY, IOWA
OR THE PAST two years general intelligence tests, each of about three hours’ duration, have been given to freshmen within two weeks after registration in the State University of Iowa. These tests are designed to indicate fitness for doing college work. The variation in intelligence, as measured by these tests, represented in a freshman class is indicated in Fig. 1. Comparatively few students are notably superior or inferior. The great majority of students are of “average” intelligence. Where large numbers of students are concerned, it is normally expected that of all who pass 5 per cent will receive A, 20 per cent B, 50 per cent C, 20 per cent D, and 5 per cent E and Conditioned. The distribution of original intelligence ratings is similar to the distribution of grades normally expected. (Compare Figs. 1 and 2 . ) For subsequent convenience it is desirable to express intelligence-test ratings on a relative percentile basis rather than in terms of the original scores. The relative percentile scores are obtained by giving the 1.per cent of the entire group receiving the lowest original scores a rating of 1, the n c A . ’ -est 1 per cent a rating of 2 , and so on to the highest 1per cent, who would receive ratings of 100. There is no implication that a person having a rating of 50 is of fifty times the intelligence of a person rated 1or of half the intelligence of a person rated 100, but merely that within the group the rating 50 represents intelligence midway between the best and poorest in the group. Further clas30 % sification of ratings is had by 25 06 segregating 20 % these relative percentile ratI506 ings into ten IO% n u m e r i c a 11 y e q u a l groups 5 06 called “deciles.” 0 04 The 0-10 decile I5 25 35 45 55 6 5 7 5 8 5 $ 5 105115 125 i n c l u d e s all FIG. l-DISrRIBUTION OF INTELLIGENCE RATINGS those havingratOP 1046 FRESHMAN STUDENTS ings from 0 to 10, the 11-20 decile all those having ratings from 11 to 20, and so on. KoerthZhas compared the intelligence ratings thus established with the final grades afterward mad., in courses pursued by these students, and found, in general, that students who have high ratings make high marks and students having low ratings
F
Presented before the Section of Chemical Education at the 64th Meeting of the American Chemical Society, Pittsburgh, Pa., September 4 to 8, 1922. a Doctor’s thesis, State University of Iown, 1922. 1
make low marks. Part of this relation existing between ratings and marks is graphically shown in Fig. 3. The authors are indebted to Koerth for Figs. 1, 2, and 3. The highest decile (Curve 3, Fig. 3) made 50 per cent of all the A’s made by the entire group of 1066 students, about 28 per cent of all the B’s, 10 per cent of all the C’s, and so on. The lowest decile (Curve 1, Fig. 3) made no A’s, about 2 per cent of all the B’s, and so on including 30 per cent of the total number of failures made by the entire group. The middle decile (Curve 2, Fig. 3) had grades quite evenly distributed from A’s to Failed. Any method which promises, even with partial success, to disc r i m i n a t e between superior and inferior students before they enter their classes, is worthy of investigation on the part of teachers. The remainder of this paper is an attempt at such an investigation so far as it pertains to ea i n g freshmen FIG.2-DIAGRAMMATIC REPRESENTATION OF chemistry. The data MARKING SYSTEX USED AT THE STATE UNIVERSITY OF IOWA involved in this study are contained in the following table. All grades were given without knowledge of intelligence ratings. SUMMARY OF INTZLLIGENCE RATINGS AND MARKS R E C ~ I V EIN D FRESHMEN CHEMISTRY, STATEUNIVERSITY OF I O W A , DURING YEARS 1920-21
INTELLIGBNCE
I
AND
1921-22
MARKS RECEIVED
D RATINGS A B C 3 26 44 91-100 19 20 20 46 81-90 6 23 71-80 14 61-70 9 51-60 10 41-50 10 31-40 14 21-30 24 1 3 26 11-20 20 0 3 12 0-10 232 357 TOTALS 45 132 PERCENT 4 . 7 5 13.8 37.7 24.5 Average rating of all students 7 6 . 5 56.9 57.6 42.3 Average intelligence of entire group =
E
2 2 5 7 7 10 10 18
Fd 0 2
7
2 9 10
7 17 15 14 29 84 98 8.85 10.3
9
36.0 28.7 50.67
Total Percent 94 9 96 10.2 106 11.0 93 9.8 83 8.7 10.6 100 8.6 82 14.6 138 78 8.2 8.2 78 948 99.6 99.9
..
..
....
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I X D WSTRIAL A N D ENGINEERING CHEiWIXTRY
COMPARISON OF INTELLIGENCE RATINGS WITH FINAL MARKSIN CHEMISTRY A few of the observations which might be drawn from such a comparison are mentioned. l-Students making high ’ratings are generally superior. The 296students who made ratings above 70 (see table), numerically constituting 35 per cent of the entire group, made 73 per cent of all the A’s, 52 per cent of the R’s, 38 per cent of the C’s, 17 per cent of the D’s, and 1 per cent or less of all E’s and failures. The showing is still more impressive if only the 91-100 decile is considered. 2-Students making low ratings are generally inferior. . The 294 students who made ratings of 30 or less, constituting 31 per cent of the entire 60% group, contributed less than 1 per cent of all A’s, 15 per cent 50% of all B’s.25 aer cent of CIS,42 pe; cent of 40% D’s, 49 per cent of E’s, and 61 per cent of all failures. The 30% academic hopelessness of many stu20% dents who succeed in entering this univerIO% sity is sharply indicated by the 78 students whose ratings 0% A B C D E C d F d are 10 or less. The table of data shows FIG. 3-COMPARISON O F INTELLIGENCE RATINGSthat in twoyears this WITH F l N A i GRADES MADEI N ALL SUBJECTS 8.2 Der cent of dents of lowest intelligence contributed only about 1 per cent of all the marks above the lowest passing mark. 3-In the large group of students between the upper and lower extremes there is a lack of close relation between marks and ratings.
FACTORS DETERMINING FINALGRADES If those mental qualities which are measured by the intelligence test were the sole factors in determining final grades, it follows that the lower the rating the lower would be the final grade and the higher the rating the higher would be the final grade. That is, the grade if given a proper numerical value, would be a linear function $f the rating. This relation may be graphically represented by a straight line. (Fig. 4) The equation for this graph is y = mx b, where y = the final grade, x = the intelligence rating, and m and b are constants which could be determined from the graph once i t was established from data. This formula, if true, would permit final grades to be computed directly from intelligence ratings. Of course it is rather unreasonable to ask or expect such a close correlation in a matter in which errors are so easily made as in assigning mathematically correct final grades. However, the attempt will here be made to show that, within the limits of this study, little relation exists between intelligence ratings and final marks received, except in the cases of those making superior and inferior ratings. The data showing the quantitative relation between ratings and grades is graphically shown in Fig. 4. For mathematical purposes letter grades are arbitrarily given the following numerical values: A = 3.5, B = +3, C = 4-1, D = -1, E = -3, and Fd = - 5 . The curved line in Fig. 4 represents the most probable final grade corresponding to any given intelligence rating. The circles represent the best average grades (“root mean square”) made by all the students in each decile. A casual inspection of the deviations from a straight line displayed by the curved line in Fig. 4 shows clearly that the statement that grades are linear functions of the ratings is not even approximately true. Consequently, the equation y = mx b cannot be used to compute final grades from ratings. A less graphic but more precise corroboration of the same fact arises from a statistical
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+
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treatment of the quantities, marks vs. ratings. The resulting coefficient of correlation is 0.44,which is not very high. Hence, the conclusion seems warranted that no simple causal relation exists between ratings and final marks. As a suggestion as to what factors really determine final grades, the following formulation is offered :
Y
=
f(a) 3. f@)
+f(c)
+ f(d1 -I- . . . . . . . . . .
where y = the final grade, f ( a ) = the intelligence rating, f ( b ) = number of hours spent in study, f(c) = utility of subject in future profession, f(d) = skill and aggressiveness of teacher, and so on. The conclusion is that many factors contribute to the determination of final grades in freshmen chemistry and that intelligence as measured by these tests is not the dominant one. POSSIBLE USESIN TEACHING FRRSHMEN CHEMISTRY
1-In sectioning large classes, performance is perhaps the fairest basis for sectioning, but where performance data are meager or lacking, as a t the beginning of the year, intelligence ratings may be found useful. 2--In picking out superior students or, more particularly, students who ought to be superior and are not. It is a sad fact that large numbers of students, regardless of their capacity, are content with average or even passing grades. In this study C and D grades constitute two-thirds of the total grades given. If it is known which students are of superior capacity but are failing to do work commensurate with their ability, it is possible to apply stimulating measures. 3-A promising possibility of economy in administration is offered through the earlier elimination of hopeless students. It is obviously unfair to eliminate a student for poor scholarship before he has had full opportunity to demonstrate his limitations. On the other hand, it is a mistaken sense of justice as well as an uneconomic process to spend six months or a year in deciding that a student lacks capacity to profitably pursue college work, if, with equal precision, the decision could be made in three months. By indicating students of low capacity, the intelligence test permits an earlier checking up and appraisal of those students who are apt to fail because of natural limitations. Unfortunately, it doesnot help in detecting those who are apt to fail through laziness &It is common knowledge with experienced teachers that the general excellence OI students seems to rise and I I I I I I I I I ebb from year to
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iest data inf&m in advance as to con- ditions in this reMY I I spect. Corollary to this, the proportion E= of students of high, medium, or low intelligence in a given Fd = 5 course may fluctuate widely from year to year. The pasFIG.8-RELATION BETWEEN INTELLIGENCETESTRATINGSAND FINALMARKS session of precise knowledge ihn this respect gives to the teacher added confidence in the correctness of the established minimum passing requirement. E--Intelligence-test data are helpful in evaluating the comparative merits of teachers where large numbers of teachers are teaching different sections of the same class. A fairer appraisal of the results of a teacher’s efforts is possible when the intelIigence of his students is known.
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MISCELLANEOUS OBSERVATIONS AND CRITICISMS Intelligence tests do not seem to function well with most foreign or negro students. While they are often superior students they seldom make eve2 average ratings. This fact may be due to linguistic difficulties or to lack of familiarity with habits of thought and living tacitly assumed in the materials used in the tests. The frequent recurrence of certain habits and characteristics on the part of students making low ratings has been so frequent
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as to give them prominence in the minds of the authors. These students are often late in registration and getting to work in the laboratories. They have difficulty in finding classrooms and proper teachers, in following oral or even printed directions. They are often industrious, aggressive, and persistent to an extent where these qualities almost cease to be virtues. They are frequently of superior physique and pleasing personality, often becoming prominent in athletics or student affairs. These students are apt to be rather brazen in their demands on a teacher’s time and attention. Any inability on their part to do good work is frequently attributed to the personal animosity of the teacher rather than to any limitations of their own. They learn slowly but often thoroughly. They seem able to learn a subject only up to a certain point. If this point falls below the passing requirement and the course is repeated, they profit little or nothing by the repetition. The characteristics of students making high ratings are not so clearly defined from our experience, but we can say that generally they are not conscious of their superiority. They are apt to be rather retiring, dreamy, and lacking in aggressiveness, persistence, and well-defined purpose. The table shows that more than half of the students in the 91-100 decile made C or less. It is with a feeling of our own inadequacy that we view the fact that so many of these superior students are lost in mediocrity. Possibly, sectioning according to intelligence ratings might help remedy this condition Students who have low ratings do better work in sections where the average intelligence is high than where i t is low. This may permit several interpretations. Teachers are apt to “pitch” their teaching to the intelligence of the weakest students in the class. When this is the case bright students are apt to go “wool gathering” and the dull ones to “putter” in their intellectual efforts. Where the average intelligence of the group is higher, the teaching will be pitched higher and the mental processes of the weaker students will be accelerated. The idea here advocated is that instruction will be more effective if adapted to the intelligence of the superior rather than the inferior members of the class.
Since making this study we have less confidence in the value of personal estimates formed from contacts with students. Both a pleasing personality and a plausible “human-interest” story lose potency in explaining away shortcomings when it is known that the student involved has low intelligence, and that the case in point is a characteristic and not an exceptional sample of the work of such a person. This paper has tacitly assumed that the grades recorded are accurate measures of performance and has called into question the accuracy of the intelligence-test ratings in indicating the relative merits of students. Yet, the extreme fallibility of teachers’ marks has been pointed out by Kelly3 and is here freely admitted. It is a frequent experience with many teachers that examination questions on which final grades are based are stated in such a way that they give rise to answers so poorly formulated that only a mind-reader could tell what the student really knows. In such cases readers of equal competence or the same reader on different occasions will give widely divergent grades on the same paper. Before rejecting the indications of intelligence tests as to the relative merits of students, this element of variability should be eliminated from the marking systems against which the intelligence tests are checked. The desirability of effort toward standardization and stabilization of marks as truer and more precise measures of attainment, is apparent to all who have investigated present conditions. Possibly, some of the standardized tests for particular subjects now being promulgated by workers in the field of education will render material aid in the solution of this problem.
Motion Picture Films
Local Section Officers
CONCLUSION If taken with proper allowances, intelligence tests are of considerable aid in dealing with superior and inferior students. They are most stimulating in bringing to notice faults inherent in the established system and helping correct them. Further, their development and modification with time promises to make them increasingly accurate and useful. a “Teachers’ Marks,” Teachers College bution to Education No. 66.
Columbia University, Contri-
The following local Section Officers Of the AMERICAN CHEMICAL Films ;produced by the fo1lowing companies, which are supplementary to the list published in the November issue of THIS SoCEZY have been chosen for the Year 1923: JOURNAL, are distributed by the International Committee of New Haven Northern Indiana Y. M. C. A.’s, 347 Madison Ave., New York, N. IT. Chairman: TREATB. JOHNSON. Chairman: E. N. WEBER. Corticelli Silk Mills Ohio Wool Growers Association Illinois Watch Company Kelly-Springfield Tires Keri Chickeries (poultry) Lounsebury Soule Company (shoes) Monitor Stove Works
Rice Millers of America (vitamins) Sidway Mercantile Company (baby carriages) Southern Pine Association Wahl Rope Company
The following films, some of which were included in the list published in the December issue, are among those which may be secured through the Y. M. C. A.: Belt Making and Tanning For the Good of the Commonwealth (steel) From Cocoon t o Milady’s Dress Grape Juice Industry How Life Regins How Petroleum Is Produced Making of Soap Making Cane Sirup Making Rust-Resisting Iron Making Cut Glass Making Rubber Tires
Money (metal mining) Oxygen the Wonder Worker Petroleum-From Well t o Consumer Potter Making Pure Aods-Oleomargarine Romance of Glass Story of a Box of Candy Story of Evaporated Milk Sugar Refining Terra Cotta Wonders of a Modern Oil Refinery
The Ford Motion Picture Laboratories, Detroit, Mich., in the Ford Educational Library provide educational films on various subjects including agriculture, sanitation, industrial geography, as well as some technical subjects. The films are sold outright, instead of being rented. The 1922 films are sold for $50 per reel, either standard inflammable film or noninflammable, while former reels of the Ford Weekly on inflammable stock may be obtained a t lower rates.
Vice Chairman: J. F . HUTCHINSON. Vice Chairman: P. J. BYRNE,JR. Secretary: BLAIRSAXTON. Secretary: V. C. BIDLACK. Treasurer: J. L. CHRISTIE. Treasurer: M. W. LYDON,JR. Councilor: HARRY W. FOOTE Councilor: J. A. NIEUWLAND. Member-&Large: J. A. KINGSBURY.
Louisville President: C. E. BALES. Vice President: T. J. BOSMAN. Secretary-Treasurer: C. E. GEIGER. Councilor: A. W. HOMBERGER.
Correlation of School Chemistry The following committee has been appointed to consider improvements in the correlation of high school and college chemistrv : NEILE. GORDON, University of Maryland, chairman. W. A. NOYES,University of Illinois. LYMANC. NEWELL,Boston University. R. E. SWAIN,Leland Stanford University. W. SBCBRBLOM, Phillips-Exeter Academy, Exeter, N. H. LOUISW. MATTERN, McKinley Manual Training High School, Washing-
ton, D. C. JOHN R. KUEBLER, Shortridge High School, Indianapolis, Ind.
