
SAT Math and Verbal
Population Parameters
About the SAT Math Population
Values 
Thanks to David
Thissen and Lyle Jones, of UNC's Quantitative
Psychology program for the following information.

 When the SAT scales were originally standarized
in the late 1940's they were given a mean of 500
and a standard deviation of 100. Since then there
has been "slippage" in the means such that in
recent years the mean Verbal score was about 430
and the mean Math score about 460 (with the standard
deviations remaining about the same).
 Clearly, the differential slippage of SAT means
(from the standardization of the late 1940s) has
been a source of confusion. Users would have been
better advised to focus on percentile scores rather
than scale scores on the "old" SAT reports. (The
same is true for GRE scores!)
 As of April 1, 1995, the SAT scales were changed
so that the mean became (again) approximately
500 both Verbal and Math, with standard deviations
of about 100. While that's "current", it is probably
not the scale that most of you taking psych 30
would have scores on. Those would be on the old
scale, where the mean Verbal was about 430 and
Math about 460.
 Last year's observed averages are reported
in a
story (they are 505 V, 508 Q). There is a
complete
table where old scores have been converted
to the new recentered scale for comparison.
 Finally, the College Board reports the
standard deviation
and percentiles from last year (they are reported
as being 110 for Verbal, 112 for Quantitative),
as well as the SAT's predictive validity
(how well it predicts college performance) and
reliability
(how stable the scores are).

