2/9/00 Survey Methodology Survey Design EPID 626 Lecture 5

2/9/00 Lecture Overview Discussion about survey study design issues Hands-on exercise with WIN data

2/9/00 Methods of data collection Mail survey Telephone survey Personal interview Computer-assisted interview

2/9/00 Considerations Available information Survey population skills and motivation Desired data Response rates Resources (money and time)

2/9/00 Mail survey Available information? –Need complete and accurate addresses Survey population skills and motivation? –Reading, writing, language skills –Knowledge of topic –Interest in subject –Limited opportunity to convince someone to participate

2/9/00 Mail survey (2) Desired data? –No interviewer involved to clarify, prompt or establish rapport –Respondents have more time to consider responses –Can access hard-to-reach samples –Difficult to designate a respondent

2/9/00 Mail survey (3) Response rates –May be very low –May increase with telephone follow-up Resources –Relatively low cost –Requires minimal staff and facilities

2/9/00 Telephone survey Available information? –Need a good list of telephone numbers if you’re not using RDD Survey population skills and motivation? –Skills needed are minimal –Language? –Limited opportunity to convince someone to participate

2/9/00 Telephone survey (2) Desired data? –May be less appropriate for sensitive or personal information –Can’t use visual aids –May miss those without phones, who screen calls, who aren’t home etc. –Have advantages of interviewer administration such as ability to clarify and probe

2/9/00 Telephone survey (3) Response rates? –Better than mail surveys –Usually not as good as personal interview –RDD especially is low Resources? –Requires less than does personal interview –May take less time than mail or personal interview surveys

2/9/00 Personal Interview Survey Available information? –May need an address –May not (area probability sampling) Survey population skills and motivation? –Skills needed are minimal –Have an opportunity to convince people to participate, establish rapport –Language?

2/9/00 Personal Interview Survey (2) Desired data? –Interviewer can explain, clarify, and probe –Can use visual aids –Rapport may encourage sharing of sensitive information –Can get more information with a longer survey –May be able to ask more open-ended questions

2/9/00 Personal Interview Survey (3) Response rates? –Usually considered very good Resources –Usually very expensive –Need a well-trained staff –Need supervision –May take a long time

2/9/00 Computer assisted survey More of a tool than a design really –Can be used as a stand-alone self- administered survey –Can be used in conjunction with telephone or personal interviews –Can use in conjunction with video to simulate a personal interview If desired, you can match some characteristics, such as age, race, and gender of the interviewer with the subject (more on this later)

2/9/00 Computer assisted survey (2) Available information? –Depends on other elements of the study design Survey population skills and motivation? –People who are not familiar with computers may feel uncomfortable –Can adjust the language –Can read questions aloud

2/9/00 Computer assisted survey (3) Desired data? –Can follow complex question patterns or questions tailored to previous answers –Can identify inconsistencies or missing data before the interview is over –Can be useful in combination with telephone survey

2/9/00 Computer assisted survey (3) Response rates? –Depends on other elements of the study design Resources? –No data entry required –If it is self-administered, no interviewer required