Richard W. Haffner
Placement of Freshmen
USAF Academy UsAF Academy, Colorado 80840
AII
cadets a t the USAF Academy must ohtuin credit for general chemistry. T h e average cadet, will satisfy this requiremeut (luring his 4th class (frcslrman) year b y completing a t x o semester scquence, Chemistry 101-102. Approximately 40-50 cadets !\-ill rntcr thc Ac:tdemy transfer credit from some othcr college or nt~iversity.bet we^^ twenty :nld thirty others can qu:rlify for validation credit and arc excused from frcshrna~lclremistry on that basis. An additional 150 mdcts \\-it11 demonstrated high nptitude in clremistry are plilccd ill :I one semcstcr, accelerated course, Chemistry 151, thc completion of which satisfies the genrral chemistry requirement. Thc dc1:tiled procedures used t o ajvard validation credit iu1d place cadcts in the accclcrlrted course are discusscd ill the remnindcr of this paper. Validation Examination A typic:~l cutoring 4th Class i l l rcport t,o the .4cndc111y on Junc 2G. Duriug the firs1 week, four m:utdntory v:~lid:~tioncx:tms :we administered irl clrrmistry, mitthcmatics, history, and English. For the 1:wt t l m r yc:u,s, thc Delxlrtmc~ltof Chcmistry hiw used tllc i\mcric:u~ Chcmical Society Cooperative Exnmi n i ~ t i ofor ~ ~G C I I C ('hcmistry, ~:~ Form lM3, for awarding valid:~ti~m crcdit. T h c ACS score is also uscd together i t other data for the placement of frcshmcn in chemistry courses. At tha timc the cx:im is givcu, :I qucstiormaire (givcn brlow) is :11st1fillcd oat. I his q u r s t i o ~ ~ ~ u risi r ~used ! t o survc? the st,udentle
in the Chemistry Program previous background in chemistry. Each cadet indicates the lmmber of semester hours of high school and college clremistry he hxs completed, the year in which he took his last course in clicmistry and whether or not his high scl~oolcourse included laboratory work. H e also states tlrc tc:icbiug method uscd in his high school coursc, c.g., Chemical Rond Approach, Chcm Study, etc. T h c c:tdet is asked if hc desires to take thc accelcratcd coursc if Ire qualifies. All of this background infornrt~tion is considered I\-hcu placing cadets in the freshmen courses. The cx:~mination is machinc graded and the results rccorded on :t card deck. From this deck tlrree separate machine listings arc printed. Thesc i t d u d e a rank order list for the ACS cxaminat,ion, ilrl alphabetical listing, and a list compiled in order of a Prcdicted C h e m i s t q Grade for e:~clr cadet,. This predicted grade will hc cxplaincd later. Ench of t,he rnitchine listings also contains thc cadet's math validation score, his aus\\-ers to the quest,ionnaire and his Acadcmic Composite. A cadet's Acadcmic Cornpositc is the sum of his four College Board tcst scores (Math Aptitudc, M a t h Achievement, Verbal Aptitude, and English Compositiou) plus his Prior Acndcmic Achievement score. These five scorcs are simply addcd together t o ohtail1 the Acadcmic Composite. I t is, in itself, a good predict,or of overall gradc point averagc arid prcdicts most course grades fairly \\-ell. ~ c a d c m i ccomposite scores 2500 t o 3750.
r
Chemistry Questionnaire Class of 1971
Sample Machine Listing 4th Class Chem ACS Order of Merit
c,rrl? r,f thr lollnuine rqurstions i n the l o n lrft ~ shaded hluo and w h i t e Ihlrvkr n u t ~ ~ h vI ~ t l~~dn n ~ li 011 d ~y n w n r r r r shret. .\rlswm
Thesc lists (samplc slrolvn above) great,ly facilitate tbc assignment of validat,iori credit and t,he placement of cadets ill t,he Chcmistry 151 course. Validation and Transfer Credit V:didation'credit is awarded t o those cadets scoriug itbovc the 85th percentile, ACS raw score of 44, ~ h do o not have transferable college credit. College transcripts are reviewed during the last w e l < in July. I h c d on a paper presented at the 1067 Southwest Regional Mecting of the American Chernieal Society in Lit,& Rock, Ark., Dcccmber 8, 1967.
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Jaurnal of Chemical Education
Toble 1.
Four Year Record of Freshman Closs Placement -Class 191W 11169 1970 1 9 7 1
Total l ? n r n l l ~ ~ $ r n t Trnnsfrrrrrl Valirlntrd Cbwu l i l
1002 50
1X 162
772
CIVW 10:
lOiR 4:J 20 l iR 834
1031
47 :i,;
156
XI):$
1035 44
:1R 151
x07
Credit is awarded t o those cadets with a B minus average or better, i r ~courses comparable t o the Academy's Chemistry 101-102 sequence, from a n accredited college or university. T h e number of cadets who transfer credit :rnd valid:~te v a r i e ~from year t o year. A four-year freshmnti class placement is sho\vn in Table 1. Selection Criteria for Chemistry 151
One of t,he prime ubject,ives inherent in the mission of the Air Force Academy is to provide each cadet with a n opportunit,y t o advance academically as far and as fast as his ability and prior preparat,ion permit. T o help meet this objective, t,he Department of Chemistry offers a n acccleratcd course (Chemistry 151) which satisfies the freshman chemistry requirement in one semester. With transfers arrd validees identified, the next step in the placement procedure is t o select cad& who \\-ill have the best possible chance of successfully completing t,his accelerated course. For this purpose t,he ACS exam scores arc again used together with the mathematics validation score and the cadet,'s Academic Composite score. These three scores are combined, by mcans of regression analysis, into a new value called the Predicted Chemistry Grade (PCG). T h e follo\ving equation is used t o compute this predicted grade: Predicted Chcmistry Grade = 1027 + 0.612 (ACS Score) 0.543 (Math Validaiion Exnm Scorc) + 0.OM (Academic Composite)
+
H:lvil~gcomputcd n P C G for each cadet, the folloming criterilr arc then used t o select cadcts for the accelerated course: Acadcmir Campositc 1!163 ACS Seon: % tile 3401-up 33013400 3201-3300 3101-32N 2901-3100 2!)00 or lcss
18 25 31 35 39 41
24 44 61 69 76 80
with a minimum P C G of 05.0. Whet1 :r cadet meets the ACS versus Academic Composite critcria but has a P C G of less than 65.0, 1.5 points cart be uddcd t o his PCG for each step down the Academic Composite versus ACS scale that he can comc : L I I ~ still be eligible. 1Por cxemplc, a cadet has these scores ACS Scwo
Academic Composite
PCG
43
2906
fi382
with ::n AOS scorc of 43 the Academic Composit,~ required is less th:tn 2900 or one step do~vn:t,hereforc, 1..50 is :idded t o the cadet's PCG. T h e cadet can thcn qualify for pl:~cemcnt in Chemist,ry 151. Rut another c:idet h:~st,Ircsc scores ACS &:ow Acadrmic Cornpositc pcC. 26
3310
64.27
This cadct meet3 the ACS vcrsus Academic Composite critcria but c::nnot come down onc Academic Composite
st,ep and still be eligible; therefore, the cadet would not be chosen for Chcmistry 151. If :: citdet meets the PCG criteria. and not the Academic Composite versus ACS crileria, 1.50 points are subtracted from the PCG for each step u p the Academic ':omposite scalc t,he cadet can go before meeting the Actldemic Composite vcrsus ACS criteria. For the class of 1971, 9'3% of the Chemistr,~1.51 curollmcnl met the basic criteria and had a PCG of 65 or greater. T h e rcmaindcr \\-we selected by makiug tr:tde-off iidjustmcnts in their ACS score, PCG, and Academic (hmposit,c as described above. These cadets, for \\-hich udjustments \I-cre m:rde, \I-ould undoubtedly have no t,roublc achieving high grades in thc basic two semester course. Howevcr, their perform:mce iu the accelerat,ed coursc is not so acc11r:rtely prcdict,ed. For this re:rsnn additiond detirilcd screening is necessary fur thosc cadcts who qualify a s a result of makiug trade-off adjust~ments. From the quest,ionn;tire, it cat1 bc det,ermined whether or not the cadet it1 qucstion \\-ants t o take ;in accelerated coursc. If he inr1ic:ites that he does not, he is usually not placed ill Chemistry 151. Also, other academic dep:rrtmcnts are queried to ascertain whctlrcr the cadet, under considerntion has been sclectcd for accelerated or advanccd courses in these departmeuts. A cadet who is a borderline choice for the m x l c r a t c d chcmistry coursc and who is cnrolled ill a n advanced fresbm:rn math course often has difficulty in Chcmistry 151. T h e rcason for this is that the math coursc is worth six semcstcr hours of credit whereas Chemistry 151 is a t \ w i u ~ done-half lrour course. The cadet naturally dcvotcs more study time to thc six-hour course. Another factor used to evaluate bordcrliue prospects is tlrcir prior ncadcmic bacligrou~id. For example, c:idets \vho enter the Academy from the Ac:~demy Prcp:iratory School have high math and English CEEB scores because these two subjects :ire taught in the Prep School. Rut, cveu though they might just qualify bcc:~use of high rZcadcmic Composites d r i c h they can tr:ide off for ACS score a ~ l dPC(;, they are not often sclcctcd for ('hemistry 151 nnless they have a minimum IYYi of (i5. From p:tst ex[)ericnce, cadcts coming from thc Prep SChl~ol 11carly ::I\\-ays have troubl~: with chemistry, a fact \\-hich is not obvious from the Academic ( ! o m p s i t e :rlonc. 0 1 1 t.hr other hand :i borderline c:ulct who h:rs had a y e w of college chemistry before entering the Academy, but \\-hnsc gr:ules were slightly belo\\- a I3 minus :rud thcrrforc not tra~~sferablc, might bc :L very good prospect for the one-semester chemistry course. 111 summ:rr.v, the sclcct~iou of ir large majority of ('.h~mistry151 st u d c ~ t sis grc:itly sin~plificdby using the mil~imumP(!G v:iluc of 6 5 . This simple criterio~i :rutorn:~tically sclccts over 90% of the cnrnllmcut. An cxpericnccd f;tcult,y membcr is thcn free t o screen in detail ;L sm:r11 group of borderline prospects :IS outliucd trbovc. I n this way :L maximum number of cadets can t:ilie Chemistry 151 \r.it,h a high probability of satisf:rctorily completing the course. Turnback from Chemistry 1 5 1
ICvcn with careful screc~~ing, :r few cadcts \\-ill uot bc ;iblc to cope \\it11 the ::ccclcr:ited coursc. Sincr the sclcctinn prucess is not perfect, it I\-onld bc unfnir t o put a cadet into the accelerated coursc and then fail Volume 46, Number 3, Morch 1969
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161
him when he does not perform as predicted. Therefore, the minimum final grade given in Chemistry 151 is C. However, a deficient cadet, once identified, is turned back to the basic course, Chemistry 101, and must complet,e the two semester sequence. The first turnback occurs at the l l t h lesson of the first semester with approximately three-fourths of the semester remaining. The cadet's performance is evaluated on the basis of an hour exam and three or four quizzes. Cadct,s whose grade averages are more than t,wo standard deviations below the mean a t this point are considcred for turnhack. Akhough t ~ stano dard deviations llras not initially intended to he a hard and fast cutoff point, past experience has proved it to he a good place to "rescue" an overburdened cadet. The Chemistry 151 and 101 lesson schedules are arranged so that a t the l l t h lesson both courses have covered the same material. Furthermore, both courses use t,he same text so that the cadet who turns hack does so v i t h little or no disruption or confusion. The Chemistry 161 exam grade is not transferred along with the cadet. Instead he is able t,o t,alce the first hour exam in Chemistry 101. The turnhack, therefore, gets a fresh start and is not penalized for his poor showing in the accelerated course. H e does lose the advantage of an open slot in his spring semester schedule. I n any given year the number of turnbaclcs is very small. For example, last year five cadets were turned hack during the semester and two who scored poorly ou the 151 final exam were required to take the second semester of the basic sequence (Chemistry 102). Evaluation of the Predicted Chemistry Grade
During the four years that the PCG has been used to place cadets into Chemistry 151, records shorn that it is the best predictor available. Each year the correlation between Chemistry 151 final numerical averages (claqs order of merit) and several different predictors is determined. Table 2 lists the coefficients of correlation for four of these. Without exception, the PCG has been the best index of a cadet's ability to perform well in the accelerated course. I t is a better predictor than any of the three individual scores of which it is comprised. The average ACS scores of thc various freshman groups for the Class of 1971 are conhined in Table 3 together with the corresponding percentile ranking and average PCG for each group. Other Uses of the Predicted Chemistry Grade
In addition to placing cadets in the accelerated course, the PCG is used to section all cadet,s t,aking
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Journal of Chemical Education
Table 2. Correlation of Several Predictors with Chem 151 Final Grade Averages clnaa ACS Raw Srorr r i d r x r ~ i rComposite
al:+
I'I~PF,,,~
106~ I14B
m n
f1.17
0.30 11.27 11.11
0.6l
0.40
OM2
10711 0:Ii
0:Ii
0.34
11.8:
11.2:
11.22
0..3
ll.d2
Prr,llctecl Cllr,,,istr!,
Gind?
I!I~I
Chemistry 101. Those cadcts with the highest PCG's are assigned t,o "A" sections or classcs, the ncxt highest PCG's go into '73" sections and so on. Each cadet is placed into a section along JT-ithother cadets who have t,he same, or nearly the same, PCG. By using the PCG, homogenous sectioning is achieved. This scheduling process is all done automatically by computer since the PCG for each cadet is part of the master tape record. Next year the number of cadets taking freshman chemist,ry a t the Academy is expected to exceed 1100. T o handle such a large group, the creation of t,wo freshman chemistry courses (in addition to Chemist,ry 151) has been proposed. Chemistry 101-102 would continue t o be thc lo\'cnt level course v i t h an estimated enrollment of 320. A new, t,wo semester sequence, Chemistry 121-122, would be established and would cover more topics in greater depth. The enrollment of t,his course would be approximately 600. The PCG will he used to place cadets into one of thesc t ~ basic o courses. Summary
The Predicted Chemistry Grade, as used at thc h i r Force Academy, is a valid and useful tool for placing cadets into freshman chemistry courses which vary in degree of difficulty and acceleration. The PCG has proved to be the best single predictor of a cadet,'s performance in General Chemistry. The ACS Cooperative Exam score is an important component of the PCG, and in addit,ion, .4CS scores are used to award validation credit in chemistry. A procedure whereby studends placed into an accelerated course can transfer to a lower lcvel course without losing step ~viththeir contemporaries is not only desirable but essential, since placement in advanced or accelerat,ed courses is not 100% accurate.
