Questionnaire Dwelling Unit-Level and Person Pair-Level Sampling ...

assisted in bias reduction, ease of modeling, and workload reduction. Exhibit 7.3 provides more
details of the data partition for GEM modeling. The resulting sample sizes of selected and
respondent units for the pair and QDU data partitions are shown for the 2002–2006 surveys in
Table 7.1.
It may be noted that for the pair data in the 1999, 2000, and 2001 surveys, the built-in ev
control feature of GEM was not used until the final respondent pair ev adjustment step. The
reason for this is that the definition for ev domain was not finalized before the pair data
calibration process was begun. However, for the 2002–2006 survey pair data, the built-in ev
control feature was used for each adjustment step.
Exhibit 7.1 Summary of 2006 NSDUH QDU Sample Weight Components
Phase I Screener Dwelling Unit Level
Design Weight Components
#1 Inverse Probability of Selecting Census Tract
#2 Inverse Probability of Selecting Segment
#3 Quarter Segment Weight Adjustment
#4 Subsegmentation Inflation Adjustment
#5 Inverse Probability of Selecting SDU
#6 Subsampling of Added SDU Adjustment
#7 SDU Release Adjustment
Weight Adjustment*
#8 SDU Nonresponse Adjustment (res.sdu.nr)
#9 SDU Poststratification Adjustment (res.sdu.ps)
#10 SDU Extreme Value Adjustment (res.sdu.ev)
Phase II Questionnaire Dwelling Unit Level
Design Weight Component
#11 Inverse of Selection Probability of at Least One Person in the Dwelling Unit
Weight Adjustment*
#12 Selected QDU Poststratification to SDU-based Control Totals (sel.qdu.ps)
#13 Respondent QDU Nonresponse Adjustment (res.qdu.nr)
#14 Respondent QDU Poststratification to SDU-based Control Totals (res.qdu.ps)
#15 Respondent QDU Extreme Value Adjustment (res.qdu.ev)
QDU = questionnaire dwelling unit; SDU = screener dwelling unit.
* These adjustments use the generalized exponential model (GEM), which also involves
pre- and post-processing in addition to running the GEM macro. See Exhibit 4.1 (Chen
et al., 2008). For computational feasibility, all weight adjustments were done using the
four model groups based on census regions defined in Exhibit 7.3.
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