Skip to main content
Skip Navigation
IES    
NCES
National Center for
Education Statistics
Menu
Contact
Tools
ED.gov
Newsflash
Search IES

Table of Contents  |  Search Technical Documentation  |  References

NAEP Analysis and Scaling → Estimation of Population and Student Group Distributions → Examining the Population-Structure Models Used in NAEP → Proportion of Variance of the Group-Defining Contrasts Accounted for by the Principal Components Used in NAEP Student Group Distribution Models → Proportion of Variance of the Group-Defining Contrasts Accounted for by the Principal Components Used in the Population-Structure Model, Grade 4 Mathematics Combined National and State Main Assessment: 2005

NAEP Technical DocumentationProportion of variance of the group-defining contrasts accounted for by the principal components used in the population-structure model, grade 4 mathematics combined national and state main assessment: 2005
Type of contrast Number of contrasts Mean Minimum Maximum Number of contrasts by proportion1 of variance explained
0.00 - 0.70 0.71 - 0.80 0.81 - 0.90 0.91 - 0.95 0.96 - 1.00
1(Total Variance – Residual Variance)/Total Variance, where Total Variance consists of both sampling and measurement error variance.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2005 Mathematics Assessment.
All contrasts 1,382 0.90 0.57 1.00 23 138 399 376 446
Student questionnaire 90 0.90 0.60 0.99 2 9 24 24 31
Major reporting variables 104 0.94 0.73 1.00 0 2 26 17 59
Interactions between reporting variables 500 0.90 0.57 0.99 16 32 139 151 162
Teacher questionnaire 554 0.89 0.69 0.99 3 81 166 141 163
School questionnaire 134 0.89 0.66 0.98 2 14 44 43 31
Last updated 13 May 2009 (RF)

Printer-friendly Version


IES    
NCES
National Center for
Education Statistics
Explore the Institute of Education Sciences