Professor Mark J. Perry's Blog for Economics and Finance
Saturday, August 22, 2009 More on the Gender Gap for NAEP Test
Scores 4. At the 90th percentile of performance, the gap between
male and female test scores increases for the economics,
mathematics and sciences exams, compared to the gap for all
students on those exams. As Dr. T says in a comment on this CD
post, "exceptional boys do much better than exceptional girls,"
and this is a direct consequence of the fact that male test
scores have a higher variance (and standard deviation) than
female test scores. In other words, even if the mean scores were
the same for males and females on these exams, the top 10% of
male students would have higher test scores on average than the
top 10% of female students. 5. Female students scored 13 points
on average higher than males for the reading exam, and 18 points
higher for the writing exam, and both differences were
statistically significant (1% level or higher). 6. At the 90th
percentile, the female-male gap narro