Question:

About this Poll
The survey findings presented in this release are based on the results of interviews conducted October 26 – October 30, 2016. Most of the interviewing for this survey was conducted prior to the FBI’s statement on October 28th about Secretary Clinton’s emails (625 of the 863 interviews). The interviews were conducted at the Center for Opinion Research at Franklin & Marshall College on behalf of the Center for Politics and Public Affairs. The poll was designed and administered by the staff of the Center for Opinion Research. The data included in this release represent the responses of 863 Pennsylvania registered voters, including 418 Democrats, 327 Republicans, and 118 Independents. The sample of registered voters was obtained from Labels & Lists. All sampled respondents were notified by letter about the survey. Interviews were completed over the phone and on-line depending on each respondent’s preference. Survey results were weighted (age, gender, region, education, and party registration) using an iterative weighting algorithm to reflect the known distribution of those characteristics as reported by the Pennsylvania Department of State.

The sample error for this survey is +/- 4.4 percentage points when the design effects from weighting are considered. The sampling error for the 652 likely voters is +/- 5.1 percentage points. In addition to sampling error, this poll is also subject to other sources of non-sampling error. Generally speaking, two sources of error concern researchers most. Non-response bias is created when selected participants either choose not to participate in the survey or are unavailable for interviewing. Response errors are the product of the question and answer process. Surveys that rely on self-reported behaviors and attitudes are susceptible to biases related to the way respondents process and respond to survey questions.