IE if the top 10% was at 3.75 at the end of 1st semester, is that number going to change after 2nd semester?

My thought is yes. I'm basing this on the 2L class cutoffs, which are lower than the 1L ones. (1L top 10% is 3.75, 2L top 10% is 3.70). It also makes sense that some of the people that did really well will fall, because it is really easy to fall (one bad grade). But less people will rise because it is much harder to raise your gpa from a 3.7 to a 3.8 unless you get all As second semester.

Any science to this? Experience?

My School:

2010 Incoming Class:
Fall cutoffs--top 5% = 3.74, top 10% = 3.54
Spring cutoffs--top 5% = 3.66, top 10% = 3.54

2009 Incoming Class
Fall cutoffs--top 5% = 3.68, top 10% = 3.56
Spring cutoffs--top 5% = 3.62, top 10% = 3.54

The remaining cutoffs (top 15%, top 20%, etc.) remained about the same.

Limited evidence, but I think just the very top of the curve fluctuates. I think more people hog the A's first semester than second. Once other smart people figure out the skills required for law school exams, the grades become more distributed, resulting in people at the top of the class to get a few B+'s, etc.

Wondering the same thing... anyone else have data from their school?

At Cornell:

The 10% cutoff was the same after Fall and Spring of last year (2010-11)
The 10% cutoff was the same after Fall and Spring of this year (2011-12).

Oddly enough, it was the same number, too.

Its called regression to the mean.

Not at uiuc this past year went from 3.66 to 3.78 for top 10% cutoff betweent first and second semester

Just got our data: our top 10% fell by .3 points. However, each other cutoff actually went up (top 15%, top 25%, top 33%, etc). Odd.

3.72. However, other cutoffs went down.

Our GPA cutoffs rise each semester.