November 2016 Winthrop Poll of Likely Voters in VIRGINIA
The November 2016 Winthrop Poll interviewed 712 LIKELY VOTERS in the VIRGINIA presidential election. After weights
(for sex, age, and race) have been applied, results which use all respondents
have a margin of error of approximately +/- 3.6% at the 95% confidence level. Subgroups
have higher margins of error. Margins of error are
based on weighted sample size.
The survey was in the field from 10/23-10/30, 2016. Phone calls were made
during weekday evenings, all day Saturday, and Sunday afternoon and evening. Weekday
daytime calls are not made to avoid oversampling those who are more likely to
be at home during the day (e.g. retirees, stay-at-home-moms, etc.). Conducting
weekend calls is important to avoid systematically excluding certain
populations (such as those who may work 2nd or 3rd shift during the week).
The survey used (1) Registered Voter Sample (wireless and landline phone
numbers of registered voters in Virginia), (2)Random Digit Dialing (RDD), and(3) wireless phone number sampling. Both RDD and wireless samples are crucial
to ensure no adult in the geographical area of interest is systematically
excluded from the sample. All samples were purchased from Survey Sampling International
(SSI). A further explanation of RDD methodology, with descriptions taken from
SSI’s website, may be found below.
Phone numbers selected for the survey were re-dialed five or more times in an
attempt to reach a respondent. Once a household was reached, we also employed
procedures to randomize within households for RDD sample.
1. Screen for confirmation of voter registration status
2. Screen for likelihood of voting
3. Weight responses based on sex, age, and race
Computerized autodialers were not used in order to ensure the survey of
wireless phones complied with the Telephone Consumers Protection Act and all
FCC rules regarding contacting wireless telephones. The Winthrop Poll is paid
for by Winthrop University with additional support from The West Forum on
Politics and Policy at Winthrop University.
Additional Explanation of RDD Methodology : (with
descriptions taken from SSI website)
Samples are generated using a database of "working
blocks." A block (also known as a 100-bank or a bank) is a set of 100
contiguous numbers identified by the first two digits of the last four digits
of a telephone number. For example, in the telephone number 203-567-7200,
"72" is the block. A block is termed to be working if some specified
number of listed telephone numbers are found in that block.