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NAEP Analysis and Scaling → Estimation of NAEP Score Scales → Treatment of Items to Avoid Violations of Assumptions → Results of NAEP Differential Item Functioning (DIF) Analyses → Results of NAEP Differential Item Functioning (DIF) Analysis for Mathematics Long-Term Trend Assessment in 2008

# NAEP Technical DocumentationResults of NAEP Differential Item Functioning (DIF) Analysis for Mathematics Long-Term Trend Assessment in 2008

For dichotomously scored items, NAEP categorizes each item into one of three categories: "A" (items exhibiting no DIF), "B" (items exhibiting a weak indication of DIF), or "C" (items exhibiting a strong indication of DIF). A plus sign (+) indicates that items are differentially easier for the focal group (female, Black, or Hispanic students) than for the reference group (male or White students) after making an adjustment for the overall level of proficiency in the two groups; a minus sign (-) indicates that items are differentially more difficult for the focal group than for the reference group. Mathematics long-term trend (LTT) does not have any polytomously-scored items for final scaling.

Number of dichotomously scored items, mathematics long-term trend assessment, by differential item functioning (DIF) category and age: 2008
Age DIF category Female-Male Black-White Hispanic-White
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2008 Mathematics Long-Term Trend Assessment.
9 C- 0 3 3
B- 5 10 8
A 128 114 111
B+ 2 6 11
C+ 0 2 2
13 C- 1 1 0
B- 10 10 8
A 133 131 132
B+ 8 9 12
C+ 1 2 1
17 C- 10 1 0
B- 9 6 5
A 122 141 143
B+ 12 7 7
C+ 2 0 0

Items identified as 'C'  items in at least one comparison, mathematics long-term trend assessment, by block and age: 2008
Age Block Item Scale1 Comparison Group favored
1 Single overall scale.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2008 Mathematics Long-Term Trend Assessment.
9 M1 N292101 Mathematics LTT Black-White White
M1 N292101 Hispanic-White White
M1 N293501 Black-White White
M4 N313701 Black-White Black
M4 N313701 Hispanic-White Hispanic
M4 N313801 Black-White White
M4 N313801 Hispanic-White White
M5 N288101 Black-White Black
M5 N288501 Hispanic-White White
M6 N290201 Hispanic-White Hispanic
13 M2 N294601 Mathematics LTT Hispanic-White Hispanic
M2 N294701 Female-Male Male
M2 N302701 Black-White White
M3 N324401 Female-Male Female
M3 N325401 Black-White Black
M6 N290201 Black-White Black
17 M1 N307201 Mathematics LTT Female-Male Male
M1 N307501 Female-Male Male
M1 N308501 Female-Male Female
M2 N302701 Black-White White
M2 N308801 Female-Male Male
M2 N308901 Female-Male Male
M2 N309101 Female-Male Female
M2 N309801 Female-Male Male
M3 N327201 Female-Male Male
M4 N317701 Female-Male Male
M4 N318601 Female-Male Male
M5 N297101 Female-Male Male
M6 N305601 Female-Male Male

Last updated 10 October 2011 (JL)