There are basically two numbers involved in the law school admission process: the LSAT score (at times. denoted by LSATScore) and the UGPA. In order to compare law school applicants, it is necessary to combine these two numbers into one appropriate number. There are infinitely many procedures that will convert a LSAT score and UGPA into one number. The ideal situation is when the ordering determined by the procedure agrees with the ordering determined by the admissions committee. Getting close to this ideal is the most crucial, vexing, and, very likely, the most subjective decision to be made by a law school admissions committee. The procedure we now discuss is the easiest and simplest procedure possible. We use INDEX = LSATScore + M*UGPA, where M is the number implicitly chosen by the law school and where M*UGPA denotes the product of M and UGPA. This procedue, albeit in a more awkward form, is chosen by most law school admission committees.
THE CHOICE OF M. For more detail, see Section Two. Each law school chooses M, sometimes implicitly. The average value of M is 12.334 and the median is 10.942. The value of M ranges from 4.520 (New England School of Law) to 26.966 (UC Berkeley).
THE CHOICE OF LSATScore For an applicant who has taken the LSAT exactly once, the choice of LSATScore is obvious. For LSAT repeaters, the obvious choices are the highest LSAT score or the average of the LSAT scores. LSAC implicitly recommends the highest of the LSAT scores. To
THE CHOICE OFUGPA. LSAC recommends using the UGPA chosen by LSAC. This means, for example, ignore Withdraw and Incomplete assuming that the issuing school considers these grades nonpunitive.
COMMENT. From the preceding equation, we see that increasing the LSAT score by M increases the index by M and, we see that increasing the UGPA by 1 also increases the index by M.
DEFINITION. For a given law school and a given applicant, the value of INDEX is called he applicant's admission index.
A DEFECT OF THE ADMISSION INDEX?. One can see that increasing the LSAT score by five will increase the applicant's admission index by five. Thus, for example, increasing the LSAT score from 175 to 180 has the same effect as increasing the LSAT score from 150 to 155. The same applies to UGPA. Thus, for example, increasing the UGPA from 3.60 to 3.75 has the same effect as increasing the UGPA from 3.25 to 3.40.
GETTING IN. Applicants who have a sufficiently high admission indesx are almost always accepted whereas applicants who have an egregiously low admission index are almost always rejected.
EXAMPLE. The admission index of an applicant with LSAT 163 and UGPA 3.42 and applying to a law school with index M=13 is 163 +13*3.42 = 163+44.46= 207.46. Is 207.46 a good application index? To answer is "more informaion is needed."
COMMENT. An applicant' admission index depends on the applicant (LSAT score and UGPA) and on the law school (the value of M).
In the rest of this section, we shall consider some important properties and give examples.
ADMISSION FACTOR
HOW LAW SCHOOLS CAN MAXIMIZE THE LSAT AND UGPA PERFORMANCE OF THEIR APPLICANTS OR MATRICULANTS No individual scores need be increased.
LSATScore
Use the applicants highest LSAT Score
UGPA
Use the UGPA determined by LSAC
Other Admission Factors
Ignore
The Admission Index M
Decreasing the value of M will, in general, decrease the average value UGPA and increase the average the value of LSAT. Increasing the value of M will, in general, Increase the average value UGPA and decrease the average the value of LSAT.
A PROPERTY, WITH EXAMPLES, OF THE ADMISSION INDEX
A PROPERTY OF M. When comparing two law schools, the law school with the smaller value of M favors the LSAT more than the law school with the larger value of M and the law school with the larger value of M favors the UGPA more than the law school with the smaller value of M. MOTIVATION. Now INDEX = LSATScore + M*UGPA. With M very small (e.g. M=0), we see that the value of INDEX depends entirely on LSATScore whereas with M very large (e.g. M=1000), we see that the value of INDEX depends almost entirely on UGPA. .
EXAMPLE 1. In our first example, we consider three applicants each of whom is applying to U Pittsburgh (uses M=10), U Oklahoma (uses M=15), and North Carolina Central University (uses M=20). We shall see that U Pittsburgh ranks Applicant 3 first and North Carolina Central University ranks Applicant 1 first, whereas U Oklahoma ranked the three applicants equal. We use INDEX = LSATScore + M*UGPA with M=10, M=15, and M=20, to find the relevant admission index
APPLICANT
LSAT
UGPA
ADMISSION INDEX WITH M=10 U PITTSBURGH
ADMISSION INDEX WITH M=15 U OKLAHOMA
ADMISSION INDEX WITH M=20 NCCU
Applicant 1
157
3.80
157+10*3.80=157+38=195
157+15*3.8=214
157+20*3.8=233
Applicant 2
160
3.60
160+10*3.60=160+36=196
160+15*3.6=214
160+20*3.6=232
Applicant 3
163
3.40
163+10*3.40=163+34=197
163+15*3.4=214
163+20*3.4=231
At U Pittsburgh, the relatively low value of M (M=10) benefits Applicant 3 (highest LSAT). At NCCU, the relatively high value of M (M=20) benefits Applicant 1 (highest UGPA). Can we say that the value of M=20 favors UGPA? No. We can say, for example, that M=20 favors UGPA more than M=10 does.
EXAMPLE 2. In our second example, we consider three applicants each of whom is applying to three law schools with M=29, M=30, and M=31 respectively.
APPLICANT
LSAT
UGPA
ADMISSION INDEX WITH M=29
ADMISSION INDEX WITH M=30
ADMISSION INDEX FOR M=31
Applicant 4
120
4.00
120+29*4.00=236
120+30*4.00=240
120+31*4.00=244
Applicant 5
150
3.00
150+29*3.00=237
150+30*3.00=240
150+31*3.00=243
Applicant 6
180
2.00
180+29*2.00=238
180+30*2.00=240
180+31*2.00=242
The relatively low value of M (M=29 benefits Applicant 6 (highest LSAT). The relatively high value of M (M=31) benefits Applicant 6 (highest UGPA).
A SECOND PROPERTY OF THE ADMISSION INDEX WITH EXAMPLES
the difference of the LSAT scores by the difference of the two UGPAs, where the two difference are taken to positive.
Increasing the LSAT score by M and decreasing the UGPA by 1.00 grade point (e.g. from 3.85 to 2.85) will not change the admission index.
Decreasing the LSAT score by M and increasing the UGPA by 1.00 will not change admission index.
Some consequences of the preceding result are:
Increasing the LSAT score by 1/M and decreasing the UGPA by 1/M grade poin) will not change the admission index.
Increasing the LSAT score by one-fourth M and decreasing the UGPA by 0.25 grade point (e.g. from 3.85 to 3.60) will not change the admission index.
LSAT
UGPA
ADMISSION INDEX AT A LAW SCHOOL WITH M=10
153
3.80
153+10*3.80=153+38=191
155
3.60
1.55+10*3.60=155+36=191
157
3.40
157+10*3.40=157+34=191
159
3.20
159+10*3.20=159+32=191
161
3.00
161+10*3.00=161+30=191
163
2.80
163+10*2.80=163+28=191
EXAMPLE. In this example, we are given that M=10. Two tenth of M is 2 and two-tenth of 1.00 UGPA is 0.20. For M=10, increasing your LSAT score by 2 does as much good as increasing your UGPA by 0.20. Ipso facto, For M=10, increasisng your LSAT score by 1 does as much good as increasing your UGPA by 0.10.
LSAT
UGPA
ADMISSION INDEX AT A LAW SCHOOL WITH M=12
150
4.00
150+12*4.00=150+48=198
153
3.75
153+12*3.75=153+45=198
156
3.50
156+12*3.50=156+42=198
159
3.25
159+12*3.25=159+39=198
162
3.00
162+12*3.00=162+36=198
EXAMPLE. In this example, we are given that M=12. Three-twelfth of M is 3 and three-twelfth (one fourth) of 1.00 UGPA is 0.25. Ipso facto, For M=12, increasisng your LSAT score by 1 does as much good as increasing your UGPA by0.25. Ipso facto, For M=12, increasisng your LSAT score by 1 does as much good as increasing your UGPA by 0.083310.
LSAT
UGPA
ADMISSION INDEX AT A LAW SCHOOL WITH M=12
150
4.00
150+12*4.00=150+48=198
153
3.75
153+12*3.75=153+45=198
156
3.50
156+12*3.50=156+42=198
159
3.25
159+12*3.25=159+39=198
162
3.00
162+12*3.00=162+36=198
EXAMPLE. In this example, we are given that M=12 so one-fourth M is 3. Notice that increasing the LSAT score by one-fourth M and decreasing the UGPA by 0.25, which is one fourth of 1.00 grade point does not change the admission index.
A THIRD PROPERTY, WITH EXAMPLES, OF THE ADMISSION INDEX
Given two applicants, where one has a higher LSAT score and the other has a higher UGPA, there exists a unique positive number M which will assign the two applicants the same admission index. Calculating this positive number M involves three steps: taking the diference of the LSAT scores of the two applicant, taking the dfference of the UGPAs of the two applicant, and then dividing the difference of the LSAT scores by the difference of the two UGPAs, where the two difference are taken to positive.
ADMISSION INDEX AS GIVEN BY LSAC
Attached is the latest (Monday, May 17, 2010, 10:52 AM) Admissions Index Information Sheet.
The admission index is a single number obtained by applying a formula drawn from two predictors: undergraduate grade-point aver age (UGPA) and LSAT score. Many law schools use an index formula to combine applicants' LSAT and GPA information in ways best suited to their particular admission procedures. For example, the index is often used as part of a preliminary evaluation of applicant files. An index is provided on the Credential Assembly Service (LSDAS) Law School Report in the summary section for Credential Assembly Service (LSDAS)- requiring law schools that choose to have an index computed. Each law school may specify calculations to be made in determining the index numbers that LSAC reports. If an applicant has more than one LSAT score, an index number is calculated for each score and for the average of the scores. Each school choosing to have an index computed decides whether to use the cumulative UGPA across all undergraduate schools attended or the GPA earned only at the undergraduate school granting the first four-year degree. The index is produced by (1) multiplying the LSAT score by some constant (A), (2) multiplying the UGPA by some other constant (B), and (3) adding the sum of these two quantities to a third constant (C). In symbols: Index = [(A) x (LSAT)] + [(B) x (GPA)] + C The values of the constants A, B, and C are supplied by the law schools them selves. The values of the constants chosen by a law school may be changed from time to time at the request of the law school. For law schools that participate in validity studies, the results are available for use in the selection of the constants for the admission index. Not all law schools use index formulas and those that do use index numbers do not necessarily use them in the same way. An index calculated by LSAC is not the exclusive means by which a law school may combine data reflected on the law school report and/or other data. The absence of an index on a report for a school does not mean that such calculations are or are not made by the school receiving the report. Some law schools may calculate their own admission indexes independently of LSAC.
COMMENT ON THE ADMISSION INDEX AS GIVEN BY LSAC
SITE'S COMMENT. Consider the index used by LSAC and the way it is written: Index = [(A) x (LSAT)] + [(B) x (GPA)] + C. Since convention dictates that we should multiply and divide before we add and subtract, we may delete the square brachets giving us Index = (A) x (LSAT) + (B) x (GPA) + C. The parentheses around "A" and the parentheses around "B" are certainly not needed. Are parentheses needed around "LSAT" and "GPA"? I would say that deleting these parentheses will cause no confusion. Deleting these unnecessary parentheses gives us the parentheses-free expressionn INDEX = A x LSAT + B x GPA +C. In Section One, affer letting M=B/A, our choice is A= 1, B=M, and C=0 giving us INDEX = LSAT + M x GPA.
HOW TO INCREASE THE ADMISSION INDEX BY 1
If you are applying to a law school that uses INDEX = LSATScore + M*UGPA, by definition increasing the admission index by 1 means increasing the value of INDEX by 1. To do this one can increase their LSAT score by 1 or increase the value of M*UGPA by 1. To do this, one must increase UGPA by 1/M.
S
ThINDX is used by over 80 percent of the law schools but nine of the top ninteen law schools (Yale, Hafvard, U Chicago, New York U, :U Pennsylvania, U Michigan, U Vairginia, Georgetown U, and U Texas) do not use INDX.
