Harris Interactive's online interviewing relies primarily on our Harris Poll Online (HPOL) multimillion member database as a sample source for large online surveys of U.S. adults, aged 18 and older. We also use our:

• proprietary technology for emailing to large groups of respondents and enabling large numbers of respondents to simultaneously complete the survey online
  
  
• advanced survey interviewing techniques, adapted to the online environment, including password protection, skip patterns, and visually appealing fonts and formatting

Sample Selection

Respondents for HPOL surveys are drawn from the multimillion member HPOL database. Email addresses for respondents in the database have been obtained from a number of sources, including:

• the HPOL registration site
• HPOL banner advertisements
• Epinion registrations

Online Interviewing Procedures

Interviews are conducted using a self-administered, online questionnaire, via proprietary, web-assisted interviewing software. The HPOL interviewing system permits online data entry of interviews by the respondents. Questionnaires are programmed into the system with the following checks:

• Question and response series
• Skip pattern
• Question rotation
• Range checks
• Mathematical checks
• Consistency checks
• Special edit procedures

All data are tabulated, checked for internal consistency and processed by computer. A series of computer-generated tables is then produced for each of the key sample groups showing the results of each survey question, both by the total number of respondents and by the key subgroups.

Control of the Sample

To maintain the reliability and integrity in the sample, the following procedures are used:

• Password protection. Each invitation contains a password that is uniquely assigned to that email address. A respondent is required to enter the password at the beginning of the survey to gain access into the survey. Password protection ensures that a respondent completes the survey only one time.
  
  
• Reminder invitations. To increase the number of respondents in the survey and to improve overall response rates, up to two additional reminder invitations are typically mailed at 2-4 day intervals to those respondents who have not yet participated in the survey.
  
  
• Summary of the survey findings. To increase the number of respondents in the survey and to improve overall response rates, respondents are often provided with a summary of some of the survey responses via the Internet. Respondents are sent an email that provides them access to a Web site containing the survey findings. As with the survey itself, this is a password-protected site that is accessible for a limited period (1-2 weeks).

Weighting

Completed interviews are weighted to figures obtained from the Current Population Survey (CPS) as well as key questions administered in Harris Poll monthly telephone surveys of national cross-sectional samples of 1,000 adults, aged 18 and older. We use several demographic variables (e.g., sex, age, education, race and ethnicity) as well as a variable representing the propensity of an individual respondent to be online—a composite of several factors—to generalize survey results to the national population.

Our data processing staff performs machine edits and additional cleaning for the entire data set. Our edit programs act as a verification of the skip instructions and other data checks that are written into the online program. The edit programs list any errors by case number, question number and type. Senior personnel, who inspect the original file and make appropriate corrections, then resolve these errors. We keep complete records of all such procedures.