Supplemental Materials
Nonlinear Gompertz Curve Models of Achievement Gaps in Mathematics and Reading
By C. E. Cameron et al., 2014, Journal of Educational Psychology
http://dx.doi.org/10.1037/edu0000009
45
NAEP Mathematics scale score gaps
40
35
30
25
4th grade male advantage
20
8th grade male advantage
15
10
5
0
1990¹ 1992¹ 1996 1996¹ 2000 2000¹ 2003 2005 2007 2009 2011
-5
Figure S1. Male advantage by grade in National Assessment of Educational Progress (NAEP)
mathematics scale scores from 1990 to 2011.
45
NAEP mathematics scale score gaps
40
35
30
25
4th grade not eligible advantage
20
8th grade not eligible advantage
15
10
5
0
1990¹1992¹ 1996 1996¹ 2000 2000¹ 2003 2005 2007 2009 2011
Figure S2. Socioeconomic status advantage by grade in National Assessment of Educational
Progress (NAEP) mathematics scale scores from 1996 to 2011. Not eligible = not eligible for
free or reduced price lunch.
45
NAEP mathematics scale score gaps
40
35
30
4th grade White- Black Gap
25
8th grade White-Black Gap
20
4th grade White- Hispanic Gap
15
8th grade White-Hispanic Gap
10
5
0
1990¹1992¹ 1996 1996¹ 2000 2000¹ 2003 2005 2007 2009 2011
Figure S3. White–Black and White–Hispanic gaps in mathematics in fourth- and eighth-grade
National Assessment of Educational Progress (NAEP) scale scores from 1990 to 2011.
NAEP reading scale score gaps
40
35
30
25
20
4th grade female advantage
8th grade female advantage
15
10
5
0
1992¹ 1994¹ 1998 1998¹ 2000 2000¹ 2002 2003 2005 2007 2009 2011
Figure S4. Male advantage by grade in National Assessment of Educational Progress (NAEP)
reading scale scores from 1990 to2011.
NAEP Reading scale score gaps
40
35
30
25
20
Grade 4 not eligible advantage
15
Grade 8 not eligible advantage
10
5
0
Figure S5. Socioeconomic status advantage by grade in National Assessment of Educational
Progress (NAEP) reading scale scores from 1990 to2011.
4th grade White-Black Gap
8th grade White-Hispanic Gap
45
8th grade White-Black gap
NAEP Reading scale score gaps
40
8th grade White-Hispanic Gap
35
30
25
20
15
10
5
0
1992¹ 1994¹
1998
1998¹
2000
2000¹
2002
2003
2005
2007
2009
2011
Year
Figure S6. White–Black and White–Hispanic gaps in reading in fourth- and eighth-grade
National Assessment of Educational Progress (NAEP) scale scores from 1990 to 2011.
Figure S7. A: Predicted mean trajectories for males and females for mathematics and reading
from the Gompertz model fit to data from the Early Childhood Longitudinal Study—
Kindergarten Cohort. B: Predicted male advantage in math (grey line) and reading (black line).
C: Predicted gender differences in rate of approach for reading and mathematics. IRT = item
response theory.
Figure S8. Predicted gap between African American and White students
adjusted for other demographic characteristics (black line) and not
adjusted (dashed line). ECLS-K = Early Childhood Longitudinal
Study—Kindergarten Cohort; B/W = Black/White.
Figure S9. Predicted gap between Hispanic and White students adjusted for other demographic
characteristics (black line) and not adjusted (dashed line). ECLS-K = Early Childhood
Longitudinal Study—Kindergarten Cohort; H/W = Hispanic/White.