PREDICTION:
The key is to compare the 99%+ percentile numbers of 2014 to the 99%+ percentile numbers of 2015 at the “Understanding Your Scores” College Board sites. Percentiles are the most logical way to look at this because percentiles are percentiles no matter what the scale:
In 2014, the 99%+ percentiles began at an SI of 224.
In 2015, however, the 99%+ percentiles begin at a raw score of 1430. When you convert that 1430 to the new SI you get 215 (±).
Thus, a 215 this year (being the first 99%+ percentile), is equal to 224 from last year, which was also the first 99%+ percentile. That is a drop of 9 SI points. Therefore it is reasonable to assume that the 2015 cutoff scores will drop around 9 points to be consistent with 2014 scores, using the 99%+ as the marker. That is less than the 12 point drop originally predicted by some, but a substantial drop none the less. The College Board 2014 vs. 2015 percentile numbers are clear. Anyone can look them up.
I extrapolated the numbers from the following College Board documents:
@DoTexe Yes, they can get the breakdown of their school using the GC access to the college board. So you should send the counselor email asking for the breakdown including how many high scores and how many scored 215 or higher, etc. Few big schools data will give us confident in predicting the close cut-off for Illinois. I hope few more schools in Illinois we can get these data.
I strongly don’t believe in concordance or previous years cut-off or any percentile based prediction as this year it obviously looks like many children have scored very high in 2015 PSAT. Only way to nail this down close enough is going with the actual data. Mean of total score and such don’t make much sense in predicting the NM Index score for NMSF.
@WGSK88@CA1543 Update - Well, I wish I had more specific information from you, but our GC didn’t have/wasn’t able to pull up the data I was specifically looking for. I asked her if she could provide me with a score distribution for all of the juniors. She didn’t have the selection index numbers for the students, only the total composite scores. She said that her department was basing their calculations off of those numbers even though it’s the SI that is used for NM. Anyways, the good news is that the cutoff score for the top 25% of juniors at his school (Il Math and Science) is 1400 this year. Historically speaking, between 25-30% of the class makes NMSF, which is why they used the 25th percentile as a cutoff for their internal calculations. She said that DS’ score of 1460 (SI of 218) is well within the top 25% and that she would be VERY surprised if he didn’t make NMSF, but you never know. This is a whole new ballgame this year and all bets are off. I know the composite score is not the same as the SI, but I hope that this information helps other parents and students trying to navigate the NM process this year.
@DoTexe Thanks for the information. I wish it was more elaborate based on the index scoring. What beats me is I saw someone report 1440 but SI of 219. So, I hope 1440 is the lowest to get to 218 or above. I thought 1450 will be lowest to get to SI of 218! I kind off think something is not right with 1400 being the 25% percentile in IMSA. That means IMSA will not have the 25% making it to NMSF. Something wrong here. Anyhow thanks for the information!
Your school is an excellent candidate to figure out the lowest SI for the student (at 75th percentile) scoring at 1400 TS. Perhaps this data gives hope to true believers (SI Percentiles shown are accurate and representative of actual testers, I am not one), that IL’s cutoff will remain lower or at last year’s cutoff at 215.
@WGSK88 Agreed. Take it all with a grain of salt! I know somewhere on CC there is a compilation of SI ranges per composite score. That might be interesting to see what is the lowest and highest SI for a 1400 score. Either way though, I agree that 1400 seemed pretty low for a school that usually posts high numbers of NMSF.
@OHToCollege Regarding the 25% figure, each year ~25-30% of IMSA’s class makes NMSF and the class sizes are usually around 200. This past year, as you noted in your link, 63 students out of 206 students made NMSF. I was referring to the top 25% of the students, or conversely, the 75th percentile as you correctly point out. I am not a stats persons, sorry for the confusion!
I’ll post over in that other thread too to see if the math and stats whizzes can parse anything of use out of this.
@DoTexe Sorry to keep bugging! What is your son hearing from his peers with SI? Is it lot of noise of higher SI or the children don’t talk much? In my daughter’s School there were some noise initially about scores one boy tried to collect and he did inform about 14 he knew who had scored 218 or higher when the score came out. I am surprised that IMSA can’t get the index based averages? or they not willing to share these data?
@WGSK88 He said that the kids don’t really share their scores openly with one another, so it’s been difficult to gather a lot of data. Of his close friends at school whose scores he was able to get, they scored 226, 218, 212, and 203 plus his score of 218. So the score distribution was pretty wide. His other friends at his other high school got a 216 and a 215. He hasn’t heard of tons of kids scoring >218 other than the one friend.
I was disappointed that the GC couldn’t get the index score distribution, too. I got the impression that she just did not have access to it and not that it was because she wasn’t willing to share.
If the Top 25%-30% of IMSA students (around 200) usually make SF then obviously, as you said, approximately 55-65 should make it. Your last year total of 63 of 206 is 30.5%. Even if they fall back to 25% and your GC said 1400 was the top 25% then a 218 is almost a virtual lock. Let’s be honest IMSA is one of, if not the premier HS in Illinois. It’s doubtful that they somehow regress below that 25% threshold.
Now lets consider the possibilities for a moment. I would expect IMSA students to score better on the math portion. It is a math and science academy after all That base 1400 could be a student with a perfect 760 M along with a 640 CRW. That is a 204 SI. If we go opposite (very unlikely) perfect 760 CRW and 640 M we get 216. But let’s split the difference and arrive at avg of 210 (700/700). I’d even bet slightly lower because as I mentioned before the math scores are likely higher at IMSA but are only 1/3 vs 2/3 for CRW so 208-209 for the bottom of 25th percentile and cutoff for IL. That is about what I would’ve expected before any scores were announced. That represents a 6 or 7 point drop from last year. Obviously not the straight 12 from 240 to 228 but significantly lower nonetheless. I actually am a betting man and if there was a bet on that 218 I’d call it a lock. Obviously I could be wrong but if your GC was honest about the scores (why wouldn’t they be?), then your son should make SF no prob.
@DoTexe - Either IMSA numbers they gave you is totally off. I am sorry. Since they are not even willing to give you the SI scores averages.which as per many people I have heard is easy for the GC to find out yet IMSA GC doesn’t want to share the information. Absolutely no privacy here except they want to protect the privacy of IMSA. If 210 is the cutoff my daughter’s school will have 40+ which has never happened in the history of their school Maximum they had is 23 NMSF in a year. Also, another School I know which didn’t have any NMSF last year, my friend’s son scored 220. I am trying to get some details from this School how many scored 215 or 218 or higher through my friend. I will bet Illinois cut off will not be any where below 215 (at the best case). At the worst case (for parents like me :-)) it could be as high as 219 or 220. I am waiting to see any other School has SI data that can answer some questions.
At sons Illinois south suburban HS, they usually have 2 or 3 NMSF. My son scored 218. He knows of one other 218 and one 219 of the kids he asked. No one is admitting to a higher score.
@perch1024 can he possibly find out if there are any 217’s or 216’s and if so how many? MN is usually one point less than IL so I’m very interested in this information. . . .
That base 1400 could be a student with a perfect 760 M along with a 640 CRW. That is a 204 SI. If we go opposite (very unlikely) perfect 760 CRW and 640 M we get 216. But let’s split the difference and arrive at avg of 210 (700/700). I’d even bet slightly lower because as I mentioned before the math scores are likely higher at IMSA but are only 1/3 vs 2/3 for CRW so 208-209 for the bottom of 25th percentile and cutoff for IL. That is about what I would’ve expected before any scores were announced. That represents a 6 or 7 point drop from last year. Obviously not the straight 12 from 240 to 228 but significantly lower nonetheless. I actually am a betting man and if there was a bet on that 218 I’d call it a lock. Obviously I could be wrong but if your GC was honest about the scores (why wouldn’t they be?), then your son should make SF no prob.