Bradley in DC
12-29-2007, 05:41 AM
http://www.pollster.com/blogs/timesbloomberg_ia_poll_what_of.php
TIMES/BLOOMBERG IA POLL - WHAT % OF ADULTS?
Here are some additional details on the new Los Angeles Times/Bloomberg poll in Iowa. The last Times/Bloomberg poll in September drew a sample of "caucus voters" that represented a much larger slice of the Iowa population than other polls. The Democratic sample represented 39% of Iowa adults, while the Republican sample represented 29% of adults. While this statistic varied greatly among pollsters, most have reported "likely caucus goer" samples representing a range of 9-17% of Iowa adults for the Democrats and 6-11% for the Republicans (see the second table in my Disclosure Project post).
For this most recent survey, the Times release did not report the percentage of adults represented by each sample, but they did provide the unweighted sample sizes for the four different Iowa subgroups they released. All four are considerably closer to the low-incidence samples reported by most of the other pollsters that have disclosed these methodological details, although even the smaller Democratic "likely caucus goer" sample (17% of adults, unweighted) appears to be on the high side of what other pollsters reported to our Disclosure Project.
I put "appears to be" in italics above because the more accurate weighted values may be different. The methodology blurb in the Times release implies that the weighted size of each sample may be slightly smaller. Though unclear on the details, they say they "designed" their sample to " yield greater numbers of voters and thus a larger pool of likely caucus goers for analysis." That design may mean that the weighted value of the caucus voter and likely caucus-goer samples may be slightly smaller. I emailed a request for the weighted values and, as of this writing, have not received a response.
[Update: Just received a response and added the weighted values to the table above. The weighting does bring down the size of the two "likely caucus goer" subgroups slightly, to 15% for the Democrats and 7% for the Republicans].
TIMES/BLOOMBERG IA POLL - WHAT % OF ADULTS?
Here are some additional details on the new Los Angeles Times/Bloomberg poll in Iowa. The last Times/Bloomberg poll in September drew a sample of "caucus voters" that represented a much larger slice of the Iowa population than other polls. The Democratic sample represented 39% of Iowa adults, while the Republican sample represented 29% of adults. While this statistic varied greatly among pollsters, most have reported "likely caucus goer" samples representing a range of 9-17% of Iowa adults for the Democrats and 6-11% for the Republicans (see the second table in my Disclosure Project post).
For this most recent survey, the Times release did not report the percentage of adults represented by each sample, but they did provide the unweighted sample sizes for the four different Iowa subgroups they released. All four are considerably closer to the low-incidence samples reported by most of the other pollsters that have disclosed these methodological details, although even the smaller Democratic "likely caucus goer" sample (17% of adults, unweighted) appears to be on the high side of what other pollsters reported to our Disclosure Project.
I put "appears to be" in italics above because the more accurate weighted values may be different. The methodology blurb in the Times release implies that the weighted size of each sample may be slightly smaller. Though unclear on the details, they say they "designed" their sample to " yield greater numbers of voters and thus a larger pool of likely caucus goers for analysis." That design may mean that the weighted value of the caucus voter and likely caucus-goer samples may be slightly smaller. I emailed a request for the weighted values and, as of this writing, have not received a response.
[Update: Just received a response and added the weighted values to the table above. The weighting does bring down the size of the two "likely caucus goer" subgroups slightly, to 15% for the Democrats and 7% for the Republicans].