The MCPS percentile score is based on grouping elementary schools in the county into three SES groups. They don't say exactly what criteria goes into it but the categories are something like highly impacted (by poverty), moderately impacted and mildly impacted. They may use FARMS percentage or Title I status.

For the purpose of the MCPS percentile students are only compared to their "peers" in the same SES group. So a child from Bethesda Elementary would be compared to a child from Potomac Elementary but not to a child at Arcola or Wheaton Woods which are Title I schools.

MCPS believes this helps level the playing field. As an aside, I'm not sure I get their logic. I think it makes sense to give extra points for MAP scores and other achievement-based testing but Cogat is supposed to measure raw cognitive ability so there should be about the same distribution in poor areas and wealthy areas. It shouldn't depend on prepping or enrichment.

Anonymous wrote:If they are adjusting the MCPS percentile depending on which school the kid attends, it's not a percentile and they should say that clearly in the letter.

It's kinda mean to make someone thing they're not doing well compared to others, when in fact they might be doing great.

MCPS, in my possibly ill informed opinion, may be trying to make the parents of high performing kids in high SES schools think their kids aren’t as bright as they are (and hence not in need of more advanced instruction).

Anonymous wrote:

Anonymous wrote:It's an accurate term. They are comparing your child to his peers in schools across MCPS in the same SES band.

What exactly is an SES band and why doesn't the letter say that?

It’s described vaguely on recent update to the MCPS website. There isn’t sufficient information provided to understand this so it’s all just speculation about the exact impact

Anonymous wrote:It's an accurate term. They are comparing your child to his peers in schools across MCPS in the same SES band.

What exactly is an SES band and why doesn't the letter say that?

It's an accurate term. They are comparing your child to his peers in schools across MCPS in the same SES band.

If they are adjusting the MCPS percentile depending on which school the kid attends, it's not a percentile and they should say that clearly in the letter.

It's kinda mean to make someone thing they're not doing well compared to others, when in fact they might be doing great.

Basically, if your kid got a 95% MCPS score in one SES band and another kid got 94% in a different SES band your kid is ranked higher.

-They used three SES bands to come up with the MCPS score. Your child was placed in the SES band based on his or her school.

-For each band each national percentile score should map to one or close to one MCPS percentile score.

-EXCEPT for 99th percentile national kids. Depending on the SES band you may see a large range of MCPS scores for these 99th percentile kids.

-MCPS scores, because of how they only tested about half the grade, should be lower than national scores

-The bigger the spread between the national and MCPS score the higher performing the SES band.

-Don't get caught up with the MCPS score. You child may have a 60th percentile score but still be one of the highest performing in his or her school. Think about it this way: If you take the top 100 students in MCPS and assign them some kind of "top student" percentile only one of those kids will be in the 99th percentile. The 100th student by ranking will be a 1 percentile student but in reality he's the 100th best kid in 3rd grade in MCPS out of 12,000 students or however many there are this year.

Anonymous wrote:

Anonymous wrote:The difference between national and MCPS is rather fascinating. My child (accepted) was 99 on national and 98 on MCPS. Seems so at odds with people reporting much bigger spreads. I gather this means that the "cohort" in my kid's current school is very high-scoring?

No it means their cohort is less high scoring or that there are not as many high SES kids. Your kid is more of an outlier where they are than if they were somewhere else where the (MCPS) percentile is much lower than national.

Oh right, thank you! I had it backwards. (Obviously, to the extent that my kid is highly skilled in math and/or reasoning, he didn't get it from me! )

Anonymous wrote:

Anonymous wrote:The difference between national and MCPS is rather fascinating. My child (accepted) was 99 on national and 98 on MCPS. Seems so at odds with people reporting much bigger spreads. I gather this means that the "cohort" in my kid's current school is very high-scoring?

No it means their cohort is less high scoring or that there are not as many high SES kids. Your kid is more of an outlier where they are than if they were somewhere else where the (MCPS) percentile is much lower than national.

Or if your school is known to be high SES then your kid is one of the top students in his/her cohort

Anonymous wrote:The difference between national and MCPS is rather fascinating. My child (accepted) was 99 on national and 98 on MCPS. Seems so at odds with people reporting much bigger spreads. I gather this means that the "cohort" in my kid's current school is very high-scoring?

No it means their cohort is less high scoring or that there are not as many high SES kids. Your kid is more of an outlier where they are than if they were somewhere else where the (MCPS) percentile is much lower than national.

The difference between national and MCPS is rather fascinating. My child (accepted) was 99 on national and 98 on MCPS. Seems so at odds with people reporting much bigger spreads. I gather this means that the "cohort" in my kid's current school is very high-scoring?

Anonymous wrote:Rejected with 88% national and barely above 50% MCPS.

Everyone should remember that this was a short test, so don't feel bad about your kids who did not perform well. It was a half hour on one day, not a reflection of their true talents.

Anonymous wrote:

Anonymous wrote:So, what does that mean if the national is way higher than mcps? I'm not appealing, just wondering what it means and how it relates to enrichment mentioned in the letter.

It means MCPS kids do much better than the national average.

Or that those MCPS tested (which was not everyone) did better when when compared to everyone who tested nationally. Many systems use this test with all students, it's not only used the way MCPS uses it with preselected students who have shown they are already performing on to above grade level.

Anonymous wrote:What would explain a 48-point gap bw national and MCPS percentiles?

By using roughly the upper half of testers scores get more spread out the further you get from the top. For example, a person at 50% literally could end up at 0% using this approach.