NAEP Technical DocumentationFinal Primary Sampling Unit Strata for the 2012 Assessment

The strata were defined using the selected stratifiers from the stepwise regression analysis (see Stepwise Regression Analysis Results for PSU Stratification). The cutoffs were selected so that roughly equal measures of size were represented by each stratum.

Stratification for Northeast metropolitan noncertainty primary sampling units (PSUs), by stratum: 2012
Sratum	Primary stratifier	Secondary stratifier	PSUs	Measure of size
† Not applicable. NOTE: Black includes African American. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012.
Total	†	†	46	4,553,200
1	Percent child poverty <=10.1%	Percent Black <=15.9%	8	562,721
2	Percent child poverty <=10.1%	15.9% < Percent Black <=27.7%	2	536,158
3	10.1%< Percent child poverty <=12.5%	Percent Black <=14.9%	7	586,447
4	10.1%< Percent child poverty <=12.5%	14.9%< Percent Black <=38.2%	4	627,747
5	12.5%< Percent child poverty <=13.4%	†	5	548,322
6	13.4%< Percent child poverty <=15.1%	†	7	578,078
7	15.1%< Percent child poverty <=17.0%	†	5	517,843
8	17.0%< Percent child poverty <=20.7%	†	8	595,884
Mean	†	†	†	569,150

Stratification for Northeast non-metropolitan noncertainty primary sampling units (PSUs), by stratum: 2012
Stratum	Primary stratifier	PSUs	Measure of size
† Not applicable. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012.
Total	†	50	1,111,662
1	Percent child poverty <=15.7%	23	549,880
2	15.7%< Percent child poverty <=22.8%	27	561,782
Mean	†	†	555,831

Stratification for Midwest metropolitan noncertainty primary sampling units (PSUs), by stratum: 2012
Stratum	Primary stratifier	Secondary stratifier	Tertiary stratifier	PSUs	Measure of size
† Not applicable. NOTE: Med HH Income = median household income.Asian includes Pacific Islander. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012.
Total	†	†	†	100	7,425,254
1	Child poverty <=12.5%	†	Pct Asian<=1.1%	17	627,034
2	Child poverty <=12.5%	†	1.1%<Pct Asian<=1.4%	4	664,158
3	Child poverty <=12.5%	†	1.4% < Pct Asian <=2.4%	8	591,089
4	Child poverty <=12.5%	†	2.4% < Pct Asian <=2.6%	3	697,772
5	Child poverty <=12.5%	†	2.6% < Pct Asian <=3.4%	7	601,360
6	Child poverty <=12.5%	†	3.4% < Pct Asian <=10.3%	13	610,155
7	12.5% < Child poverty <=12.9%	†	†	6	613,473
8	12.9% < Child poverty <=14.5%	†	Pct Asian <=1.3%	7	636,134
9	12.9% < Child poverty <=14.5%	†	1.3% < Pct Asian <=2.7%	7	591,225
10	14.5% < Child poverty <=27.6%	Med HH Income <=$38,291	†	17	601,878
11	14.5% < Child poverty <=27.6%	$38,291 < Med HH Income <=$46,460	Pct Asian <=0.9%	7	572,275
12	14.5% < Child poverty <=27.6%	$38,291 < Med HH Income <=$46,460	0.9% < Pct Asian <=3.1%	4	618,701
Mean	†	†	†	†	618,771

Stratification for Midwest non-metropolitan noncertainty primary sampling units (PSUs), by stratum: 2012
Stratum	Primary stratifier	Secondary stratifier	Tertiary stratifier	PSUs	Measure of size
† Not applicable. NOTE: BHI = Black, Hispanic, or American Indian/Alaska Native. Black includes African American. Hispanic includes Latino. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012.
Total	†	†	†	249	3,561,130
1	Child poverty <=15.7%	Percent college grd <=12.5%	†	41	586,227
2	Child poverty <=15.7%	12.5%< Percent college grd <=36.0%	Pct BHI <=4.2%	42	588,164
3	Child poverty <=15.7%	12.5%< Percent college grd <=36.0%	4.2%< Pct BHI <=8.5%	42	592,616
4	Child poverty <=15.7%	12.5%< Percent college grd <=36.0%	8.5%< Pct BHI <=41.4%	38	604,908
5	15.7%< Child poverty <=45.5%	Percent college grd <=13.2%	†	41	589,093
6	15.7%< Child poverty <=45.5%	13.2%< Percent college grd <=23.0%	†	45	600,122
Mean	†	†	†	†	593,522

Stratification for South metropolitan noncertainty primary sampling units (PSUs), by stratum: 2012
Stratum	Primary stratifier	Secondary stratifier	Tertiary stratifier	PSUs	Measure of size
† Not applicable. NOTE: Black includes African American. Hispanic includes Latino. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012.
Total	†	†	†	153	13,376,936
1	Child poverty <=22.7%	Percent Black <=39.7%	Percent Hispanic <=1.7%	16	601,133
2	Child poverty <=22.7%	Percent Black <=39.7%	1.7%< Percent Hispanic <=2.6%	12	630,882
3	Child poverty <=22.7%	Percent Black <=39.7%	2.6%< Percent Hispanic <=2.7%	3	578,692
4	Child poverty <=22.7%	Percent Black <=39.7%	2.7%< Percent Hispanic <=3.0%	8	576,467
5	Child poverty <=22.7%	Percent Black <=39.7%	3.0%< Percent Hispanic <=3.5%	7	664,447
6	Child poverty <=22.7%	Percent Black <=39.7%	3.5%< Percent Hispanic <=4.2%	6	648,364
7	Child poverty <=22.7%	Percent Black <=39.7%	4.2%< Percent Hispanic <=4.8%	4	638,875
8	Child poverty <=22.7%	Percent Black <=39.7%	4.8%< Percent Hispanic <=5.5%	6	514,110
9	Child poverty <=22.7%	Percent Black <=39.7%	5.5%< Percent Hispanic <=7.3%	8	591,459
10	Child poverty <=22.7%	Percent Black <=39.7%	7.3%< Percent Hispanic <=8.5%	5	533,640
11	Child poverty <=22.7%	Percent Black <=39.7%	8.5%< Percent Hispanic <=9.1%	4	725,090
12	Child poverty <=22.7%	Percent Black <=39.7%	9.1%< Percent Hispanic <=11.2%	6	709,260
13	Child poverty <=22.7%	Percent Black <=39.7%	11.2%< Percent Hispanic <=14.6%	8	579,834
14	Child poverty <=22.7%	Percent Black <=39.7%	14.6%< Percent Hispanic <=21.1%	6	541,611
15	Child poverty <=22.7%	Percent Black <=39.7%	21.1%< Percent Hispanic <=30.8%	6	699,288
16	Child poverty <=22.7%	Percent Black <=39.7%	30.8%< Percent Hispanic <=51.2%	6	712,593
17	Child poverty <=22.7%	39.7%< Percent Black <=56.6%	Percent Hispanic <=2.7%	6	545,131
18	Child poverty <=22.7%	39.7%< Percent Black <=56.6%	2.7%< Percent Hispanic <=7.8%	6	663,198
19	22.7%< Child poverty <=24.3%	†	†	11	501,477
20	24.3%< Child poverty <=45.7%	Percent Black <=2.0%	†	4	736,424
21	24.3%< Child poverty <=45.7%	2.0%< Percent Black <=60.8%	Percent Hispanic <=3.8%	11	494,354
22	24.3%< Child poverty <=45.7%	2.0%< Percent Black <=60.8%	3.8%< Percent Hispanic <=64.1%	4	490,607
Mean	†	†	†	†	608,043

Stratification for South non-metropolitan noncertainty primary samling units (PSUs), by stratum: 2012
Stratum	Primary stratifier	Secondary stratifier	Tertiary stratifier	PSUs	Measure of size
† Not applicable. NOTE: Black includes African American. Median HH income = median household income. Asian includes Pacific Islanders. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012.
Total	†	†	†	269	5,263,030
1	Percent Black <=31.2%	Median HH Income <=$36,049	Percent Asian <=0.2%	32	523,811
2	Percent Black <=31.2%	Median HH Income <=$36,049	0.2%< Percent Asian <0.3%	29	525,860
3	Percent Black <=31.2%	Median HH Income <=$36,049	Percent Asian =0.3%	32	529,321
4	Percent Black <=31.2%	Median HH Income <=$36,049	0.3%< Percent Asian <=0.4%	29	521,822
5	Percent Black <=31.2%	Median HH Income <=$36,049	0.4%< Percent Asian <=0.7%	26	548,060
6	Percent Black <=31.2%	Median HH Income <=$36,049	0.7%< Percent Asian <=3.0%	26	545,240
7	Percent Black <=31.2%	$36,049< Median HH Income <=$54,721	†	21	557,463
8	31.2%< Percent Black <=51.3%	Median HH Income <=$29,555	†	25	519,808
9	31.2%< Percent Black <=51.3%	$29,555< Median HH Income <=$44,421	†	23	502,924
10	51.3%< Percent Black <=79.4%	†	†	26	488,721
Mean	†	†	†	†	526,303

Stratification for West metropolitan noncertainty primary sampling units (PSUs), by stratum: 2012
Stratum	Primary stratifier	Secondary stratifier	PSUs	Measure of size
† Not applicable. NOTE: Percent HS graduates = percent high school graduates. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012.
Total	†	†	71	6,932,599
1	Percent HS graduates <=70.0%	Percent college graduates <=13.5%	7	663,779
2	Percent HS graduates <=70.0%	13.5%< Percent college graduates <=22.5%	4	519,908
3	70.0%< Percent HS graduates <=78.9%	†	6	534,728
4	78.9%< Percent HS graduates <=79.6%	†	3	668,300
5	79.6%< Percent HS graduates <=88.3%	Percent college graduates <=21.8%	14	565,552
6	79.6%< Percent HS graduates <=88.3%	21.8%< Percent college graduates <=25.5%	8	599,946
7	79.6%< Percent HS graduates <=88.3%	25.5%< Percent college graduates <=26.9%	4	529,564
8	79.6%< Percent HS graduates <=88.3%	26.9%< Percent college graduates <=27.8%	3	585,362
9	79.6%< Percent HS graduates <=88.3%	27.8%< Percent college graduates <=30.3%	3	556,359
10	79.6%< Percent HS graduates <=88.3%	30.3%< Percent college graduates <=39.5%	3	538,473
11	88.3%< Percent HS graduates <=90.1%	†	8	570,886
12	90.1%< Percent HS graduates <=93.1%	†	8	599,742
Mean	†	†	†	577,717

Stratification for West non-metropolitan noncertainty primary sampling units (PSUs), by stratum: 2012
Stratum	Primary stratifier	Secondary stratifier	Tertiary stratifier	PSUs	Measure of Size
† Not applicable. NOTE: Percent HS graduates = percent high school graduates. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012.
Total	†	†	†	102	1,725,933
1	Percent college graduates <=21.0%	Median child poverty <=17.3%	†	26	444,251
2	Percent college graduates <=21.0%	17.3%< Median child poverty <=43.0%	Percent HS graduates <=77.3%	23	421,744
3	Percent college graduates <=21.0%	17.3%< Median child poverty <=43.0%	77.3%< Percent HS graduates <=86.4%	28	417,700
4	21.0%< Percent college graduates <=42.6%	†	†	25	442,238
Mean	†	†	†	†	431,483

Last updated 26 February 2016 (GF)

Printer-friendly Version