1. Public Health
Information Network (PHIN)
Series II
Outbreak Investigation Methods:
From Mystery to Mastery

3. Access Series Files Online
http://www.vdh.virginia.gov/EPR/Training.asp
 Session slides
 Session activities (when applicable)
 Session evaluation forms
 Speaker biographies
Alternate Web site:
http://www.sph.unc.edu/nccphp/phtin/index.htm

4. Site Sign-in Sheet
Please submit your site sign-in sheet and
session evaluation forms to:
Suzi Silverstein
Director, Education and Training
Emergency Preparedness & Response Programs
FAX: (804) 225 - 3888

5. Series II
Session V
“Interviewing Techniques”

6. Series II Sessions
Title Date
“Recognizing an Outbreak” June 2
“Risk Communication” July 7
“Study Design” August 4
“Designing Questionnaires” September 1
“Interviewing Techniques” October 6
“Data Analysis” November 3
“Writing and Reviewing Epidemiological December 1
Literature”

7. CDC
Outbreak Management System
Software Support: National Center for Public Health Informatics
outbreakms@cdc.gov / (800) 532-9929, option 6

8. OMS Applications
• Track demographics, case investigations, and
exposure contact relationships for persons,
animals, events, travel events, vehicles, objects,
organizations, other organisms, and locations.
• Create household, social, or occupational
relationships among records
• Run OMS on desktops or laptops [CAPI]

9. OMS User Interface
Source: http://www.cdc.gov/phin/software-solutions/oms/index.html

10. OMS User Interface
Source: http://www.cdc.gov/phin/software-solutions/oms/index.html

11. OMS in Virginia
Contact:
Michael A. Coletta, MPH
Bioterrorism Surveillance Coordinator
Division of Surveillance and Investigation
Office of Epidemiology
Telephone: (804) 864-8099
Email: michael.coletta@vdh.virginia.gov

12. Today’s Presenters
Aaron Wendelboe, MSPH
Doctoral Candidate and
Graduate Research Assistant,
NC Center for Public Health Preparedness
Erin Rothney, MPH
Research Associate,
NC Center for Public Health Preparedness

13. “Interviewing Techniques”
Learning Objectives
Upon completion of this session, you will:
• Recognize the interrelatedness of
interview techniques and questionnaire
design
• Understand key survey research terms
• Understand the advantages and
disadvantages of face-to-face, telephone,
and computer assisted interview methods

14. Learning Objectives (cont’d.)
• Understand the advantages and
disadvantages of mail and Web-based
survey implementation
• Know what to address in interviewer
training
• Recognize good interview techniques
• Understand confidentiality concerns from
the perspectives of both the respondent
and the outbreak investigator

15. Lecturer
Aaron Wendelboe, MSPH
Doctoral Candidate and
Graduate Research Assistant,
NC Center for Public Health Preparedness

16. Basic Steps of an
Outbreak Investigation
1. Verify the diagnosis and confirm the outbreak
2. Define a case and conduct case finding
3. Tabulate and orient data: time, place, person
4. Take immediate control measures
5. Formulate and test hypothesis
6. Plan and execute additional studies
7. Implement and evaluate control measures
8. Communicate findings

17. Interviewing Techniques
Introduction

18. Introduction
• The role of interviews in outbreak investigations
• Types of interviewing methods
• Interrelatedness of interview method and
questionnaire design
• Key survey research concepts
– Sampling
– Response rates

19. Role of Interviews in
Outbreak Investigations
Primary purpose: data collection
• Case identification
• Risk factor identification
• Hypothesis generation

20. Interviewing Methods
1. Interviewer Administered
– Face-to-face
– Telephone
2. Self Administered
– Mail-out
– Email
– Web-based
3. Combination of 1 and 2

21. Questionnaire Design
Interview Method Influenced by:
• Length and format of questionnaire
• Question types used in a survey
• Cost considerations for survey
implementation

22. Sampling

23. Sampling
Sampling is the systematic selection of a
portion of the larger source population. A
sample should be representative of the
larger source population.

24. Sampling
Source Pop: Students (12,000)
Sampled pop (150 students)

25. Sampling
Why Sample?
Because it is more efficient – saves time
and money!

26. Sampling
Sample size
Is the purpose of the study to determine the
source of the outbreak?
– A small number of cases and controls can reveal risk
factors for infection.
Is the purpose of the study to determine the
number of persons who become sick over a
specific period of time [attack rate]?
– A cohort study would require a larger sample.

27. Sampling
Types of Sampling
Simple Random Sample (SRS)
Randomly select persons to participate in study.
There are many variations of SRS.
Convenience Sample
Choose those individuals who are easily
accessible.

28. Sampling
Problems with Convenience Sampling
• Based on subjective judgment
• Cases may or may not be representative
of the total population
• May lead to biased results

29. Sampling
Additional Resources:
http://www.sph.unc.edu/nccphp/training/all_trainings/at_sampl.htm
1. “Sampling Case Studies”
2. “Survey Sampling: Precision, Sample Size,
and Conducting a Survey”
3. “Survey Sampling Terminology and Methods”

30. Response Rates

31. Response Rates
Response rates measure the percentage of your
sample that has participated in your survey.
Example:
Using the campus directory, you email a survey
to a random sample of 100 freshmen. 40 of
those students complete the survey and return it
electronically. Your response rate is 40%.

32. Response Rates
High response rates ensure that survey
data are representative of the source
population, and that results will be valid.

33. Response Rates
Types of Non-response
• Non-contact: No one at home
• Refusal to participate
• Inability to participate (due to language
barrier or physical or mental condition)

34. Response Rates
What is an average response rate?

35. Response Rates
Determining Response Rates
Refer to the American Association of Public
Opinion Research website:
www.aapor.org
– Link to the document titled, “Standard
definitions” from the home page.

36. Interviewer Administered
Data Collection Considerations

37. Interviewer Administered
Data Collection
• Advantages and disadvantages of
face-to-face interviews
• Advantages and disadvantages of
telephone interviews
• Advantages and disadvantages of
Computer assisted interviews

38. Face-to-Face Interview
Advantages:
• Higher response rate
• Longer survey instrument
• Can have more complex skip patterns
• More accurate recording of responses
– Less item non-response
• Appropriate for hard to reach populations
(e.g., illiterate, institutionalized)

39. Face-to-Face Interview
Disadvantages:
• Costly
• Potential for interviewer error
• Less anonymous than self-administered
– Potential for dishonesty

40. Telephone Interview
Advantages:
• Less costly than face-to-face
• Higher response rates than mailed
• Quicker access to participants
• Supervision of interviewers feasible
• Can collect more sensitive information
• Survey design can be more efficient

41. Telephone Interview
Disadvantages:
• Lower response rates than face-to-face
• Shorter questionnaires used
• Unable to capture important visual
information (e.g., rash, working conditions)
• Under-coverage (e.g., population without
phones)
– 2.1% of total population in Virginia

42. Computer Assisted Interviewing
(CAI)
• CATI – Telephone
• CAPI – Personal
• ACASI – Audio

43. CAPI Example:
NC PHRST Teams
NC PHRST Team public health
professionals use PDAs* for rapid needs
assessment face-to-face interviews.
* PDA: Personal Digital Assistant, also sometimes called
hand-held computers, palmtops, and pocket computers

44. Field Data Collection
EPI Info
GIS
Wireless: WIFI
802.11 or Bluetooth
Field Team 4 Field Team 5
Field Team 1 Field Team 2 Field Team 3
Field data collection using IPAQ Pocket PCs equipped with GPS, GIS software and data collection forms.

47. Pros: Pros:
• Inexpensive • Eliminates double data entry
• No special skills required for • Provides routing and direction-
finding for field teams
data recording
• Improved randomization
through GIS
• Ability to quickly analyze and
map data
Cons:
Cons:
• Technology is expensive
• Requires double data-entry
• Learning curve / required
– Greater risk of data errors training for data entry
• Clipboard and paper more • Small screen size requires
cumbersome in the field scrolling through many
questionnaire pages

48. For More Information. . .
Steven Ramsey, RS
Team Leader / Industrial Hygienist
PHRST-5
Guilford County Health Department, NC
(336) -641-8192

49. Self Administered
Data Collection Considerations

50. Self-administered
Data Collection
• Advantages and disadvantages of
mailed questionnaires
• Advantages and disadvantages of
Web-based questionnaires

51. Mailed Questionnaire
Advantages:
• More anonymous
• May collect more honest responses
• No interviewer error
• Less expensive
• Respondent has more time to think about
question

52. Mailed Questionnaire
Disadvantages:
• Questionnaire must be simple
• Higher item non-response
• Lower response rate
• Data collection takes more time
• Sample population must be literate
• Coverage / frame deficiencies

53. Web-based Questionnaire
Advantages:
• Among some populations, most people
may have access to the Web / email
• Inexpensive and fast
• No data entry required
– Improves data quality
• Many vendors send data in a variety of
formats

54. Web-based Questionnaire
Disadvantages:
• Mandatory access to and experience with
Internet
• Potential connection speed and hardware /
software capacity limitations
• Potential for multiple responses from one
individual
• Potential for responses from non-sampled
respondents
• Need email address list to contact sample

55. Web-based Questionnaire
Example: Dartmouth University: 698 (13.8%) of 5060
students had conjunctivitis in spring 2002
• To identify risk factors...
– web-based questionnaire set up
– E-mail sent to 3682 undergraduates
– No data entry - rapid analysis
• 1832 responded (50% response rate)
-- Source: An outbreak of conjunctivitis due to atypical Streptococcus
pneumoniae. N Engl J Med. 2003;348 (12):1112-21.

56. Web-based Questionnaire
For a list of vendors that provide Web-
based survey tools, please visit:
http://www.surveymonkey.com/Pricing.asp

57. Question and Answer
Opportunity

58. 5 minute break

59. Standardizing Interviews

60. Standardizing Interviews
• The goal of standardization is to help
minimize error, thereby yielding better
data quality
• Minimizing interviewer error is done
through making surveys more standard or
consistent

61. Error
Interviewer Error:
Deviation from expected answer due to
the effects of interviewers.

62. Interviewer Error
Example: Gonorrhea outbreak
Bias Variance
Interviewers probe on A male interviewer
the sexual history may elicit different
section more among responses from a
non-whites than female respondent
whites than a female
interviewer.

63. Error
Additional Resource
Schwarz, N., Groves, R., and Schuman,
H., “Survey Methods” Chapter 4 in Gilbert,
D. et al (Eds) (1998). The Handbook of
Social Psychology. Boston: McGraw-Hill;
pp 143 – 179.

64. Standardizing Interviews
Contributing Factors:
1. Question wording
2. Interviewer selection
3. Interviewer training
4. Interviewing procedures
5. Supervising interviewers

65. 1. Question Wording

66. Question Wording
Criteria for Standardized Interview Questions
• Must be fully scripted
• Must mean the same thing to every respondent

67. 2. Interviewer Selection

68. Interviewer Selection
Criteria for Telephone Interviewer Selection
• Ability to read questions fluently
• Clear and pleasant telephone voice
• Responds quickly to respondent’s
questions
• Reliability

69. Criteria for Face-to-Face
Interviewer Selection
• Logistical skills (reading maps)
• Good interpersonal skills
• Independent workers
• Reliability
• In certain circumstances, parallel
demographic characteristics among
interviewers and interviewees

70. 3. Interviewer Training

71. Interviewer Training
• Training is NOT optional!
• Trainings must be interactive
• Interviewers must practice reading
questions out loud
• Provide support documentation (manual)

72. Interviewer Training
Elements
 Purpose of survey
 How to use data collection instrument
 Respondent selection process
 Intent and meaning of each question
 How to record/code responses
 Administering questionnaire
 Addressing participants’ questions
 Methods for improving response rate
 Tracking calls / completed surveys / call-
backs
 Confidentiality

73. Interviewer Training
Respondent Selection Process
Provide proxy respondent rules for adults
and children because proxy response
impacts:
– Data quality
– Sampling

74. Interviewer Training
Questionnaire Administration
To establish legitimacy of the survey upon
first contact, tell the respondent:
Who is calling
What is requested
Why respondent should cooperate
How respondent was chosen

75. Interviewer Training
Logistics
Face-to-Face Telephone
• Reading maps • Operation of equipment
• Getting to • Operation of CATI
respondents’ homes software (if applicable)
• Reimbursement
• Dress code
• Scheduling callbacks

76. Interviewer Training
Other Considerations
• Record some resolution to each question
– Are missing responses due to skip patterns or
errors?
• Review interview after completion
– Missing responses
– Illegible responses

77. Interviewer Training
Interviewer Manual
An interviewer manual serves as a
reference to interviewers during interviews
and as survey documentation.

78. Interviewer Training
Suggested Interviewer Manual Contents
• Background information
• Fieldwork
• Interviewing techniques
• Survey instrument terms and definitions

79. Interviewer Training
Program Example
Behavioral Risk Factor
Surveillance System (BRFSS)

80. BRFSS Interviewer Training
On-line training covers:
• Why BRFSS data are important, how data
are used
• Interviewer responsibilities
• Nuts and bolts of the interviewing process
• Interviewing techniques

81. BRFSS Interviewer Training
On-line interviewer training available at:
http://apps.nccd.cdc.gov/BRFSS_Training_Int/
General information about BRFSS:
http://www.cdc.gov/brfss/

82. 4. Interviewing Procedures

83. Interviewing Procedures
Rules
• Read questions exactly as worded
• Probe inadequate answers, if necessary
• Record answers without interviewer
discretion
• Maintain rapport with respondents
• Maintain an even pace

84. Interviewing Procedures
Read questions exactly
• Read entire question before accepting an
answer
• Clarify questions if necessary

85. Interviewing Procedures
Read questions exactly
• Use only standard definitions / clarification
provided
• Use the phrase: “Whatever x means to you”, OR
“Whatever you think of as x.”
• When asked to repeat only one of several
response options, repeat ALL options given for a
question

86. Interviewing Procedures
Probe
A probe is a standardized way to obtain
additional information from a respondent.
Use probes when a respondent’s answer
is unclear or irrelevant.

87. Probe
Examples of responses requiring a probe:
Interviewer: "In the past two weeks, have you
been swimming in a public pool?”
Irrelevant Response: “I swam in a lake at a
national park last month."
Unclear Response: “I stayed in a hotel with a
pool when I was on vacation last week."

88. Interviewing Procedures
Standard Probe Examples
• Repeat the question
• Retrieve receipts / calendars
• What do you mean? How do you mean?
• If respondent has narrowed down answer:
– Which would be closer?
– If you had to choose, which would you pick?

89. Interviewing Procedures
Recording Answers
• Do not direct respondent toward an answer
(leading)
• Do not assume that an “answer” received in
passing is correct
• Do not skip questions, even if “answer” was
given earlier
• Do not remind respondent of earlier remark if
answer differs from what you expect

90. Probing versus Leading
Example:
Interviewer: In the last 7 days, how many times did you
eat prepared food at the dorm cafeteria? Would you
say:
a. None d. 3 times
b. Once e. More than 3 times
c. Twice
Respondent:
“Oh, gee, I didn’t go very often . . . maybe a few times.”

91. Probing versus Leading
Example:
Interviewer Probe (correct)
“Which would be closer: none, once, twice, 3 times,
or more than 3 times?”
Interviewer Leading (incorrect)
a. “So, would you say twice, or three times?”
b. “Do you mean twice, or three times?”

92. Interviewing Procedures
Maintain Rapport
An interviewer should be:
• Nonjudgmental
• Noncommittal
• Objective

93. Maintain Rapport
“Any line can be said a thousand ways.”
- BRFSS interviewer training
Interviewers can put respondents at ease by
doing the following:
• Read the questions in a friendly, natural manner
• Speak at a moderate rate of speed
• Sound interested
• Strive for a low-pitched voice

94. Feedback Helps Maintain Rapport
Feedback is a statement or action that indicates
to the respondent that s/he is doing a good job.
– Give feedback only for acceptable performance - not
“good" content.
– Give short feedback phrases for short responses,
longer feedback for longer responses.
– Specific study information and interviewer task-related
comments can serve as feedback.
– Telephone interviewers should give feedback for
acceptable respondent performance 30-50% of the
time.

95. Feedback Examples
• “I see…”
• “Uh-huh”
• “Thank you / Thanks”
• “That is useful / helpful information”
• “I see, that is helpful to know”
• “That is useful for our research”
• “Let me get that down”
• “I want to make sure I have that right (REPEAT
ANSWER)”
• “We have touched on this before, but I need to ask every
question in the order that it appears in the questionnaire”

96. Interviewing Procedures
Maintain Even Pace
• Pace refers to the rate of progression
of the interview.
• Pace can vary by question type.
• Let the respondent set the pace.

97. Question and Answer
Opportunity

98. Activity:
Correct Interview Procedures
Probing vs. Leading vs. Feedback
Completion time: 5 minutes

99. Activity
Interviewer: “Are you still experiencing Diarrhea?”
Respondent 1: “I’m not sure”
Respondent 2: “I definitely had diarrhea last Tuesday”
Respondent 3: “Yes”
Activity Instructions:
How should the interviewer respond to these 3 answers?
Provide an example of either a clarification, probe, or
feedback that the interviewer could use. Try to think of one
correct use of each technique.

100. Activity
Suggested Answer
Respondent 1: “I’m not sure”
Try a clarification:
“For the purposes of this survey, we
consider diarrhea to be 3 or more loose
bowel movements in a 24 hour period.”

101. Activity
Suggested Answer
Respondent 2:
“I definitely had diarrhea last Tuesday”
Try a Probe:
“OK, but are you still experiencing
diarrhea?”

102. Activity
Suggested Answer
Respondent 3: “Yes”
Good Feedback: “I see”
Bad Feedback: “Are you sure?”
(leading)

103. 5. Supervising Interviewers

104. Supervising Interviewers
Monitoring, evaluation, and feedback
given to interviewers should focus on the
way interviewers handle the question-
answer process.

105. Other Supervision Tasks
• Scheduling interviewers
– Number of interviewers needed
– Time calls / visits will be made
• Setting up interview space
• Tracking who has been called and who
has not
• Reviewing data from completed interviews

106. Confidentiality

107. Confidentiality
Human Subjects & Informed Consent
Outbreak investigations are considered a
public health emergency, with the purpose
of identifying and controlling a health
problem. Informed consent or Institutional
Review Board (IRB) clearance are not
required.

108. Confidentiality
Human Subjects & Informed Consent
If further analysis of outbreak investigation
data is conducted for the purpose of
research, IRB approval should be
obtained.

109. Confidentiality
Respondent Perspective
Opening statement of every interview
should indicate that all information
collected will be kept confidential.

110. Confidentiality
Outbreak Investigation Perspective
• Do not discuss details about the outbreak
• Provide only a brief description of the
purpose of the survey at first contact

111. Question and Answer
Opportunity

112. 5 minute break

113. Guest Lecturer
Erin Rothney, MPH
Research Associate
NC Center for Public Health Preparedness

114. Overview
• Provide real-life examples of situations where
you will use interviewing techniques
– Face-to-face interviewing
– Telephone interviewing
• Discuss advantages and disadvantages
• Compare interviewing methods

115. Face-to-face Interviews

116. Community Assessments
• Identify the needs and strengths of a particular
community from several stakeholder
perspectives
• Include interviewing community members and
observing the environmental and individual
characteristics and community infrastructure
• Similar to rapid needs assessments, but
completed within a longer time frame

117. Durham, NC
Community Assessment
• Fall 2002 - Spring 2003
• Bragtown Neighborhood, Durham, NC
• 5 person team
• Interviewed residents and other stakeholders in
Bragtown
• 4 page survey, 60 minutes in length

118. Durham, NC
Community Assessment
Tasks:
• Questionnaire design
• Interviewer training
• Interviewing
• Facilitating focus groups
• Analyzing data
• Presenting data to the community

119. Survey Instrument
Question Examples:
Life in the Community
• What do people in Bragtown do for recreation?
• What types of religion are practiced in Bragtown?
• What do people in Bragtown do for a living?
• What political or government organizations exist in Bragtown?
• What different cultural and ethnic groups live in Bragtown?
• How do these different groups interact? Do they get along?
Community Assets
• What do you like about Bragtown?
• What are some organizations within your community that
positively affect you or your community?
– Probe: What about political groups, environmental groups, church
groups?
• Who are the individuals within your community that you feel are
positive leaders or role models?
– Probe: Any others?

120. Interviewer Training
• Active listening skills
• Showing empathy
• Using probes
• Practice interviewing, not just reading
questions

121. Face-to-face Interviews
Challenges Solutions
Hard to find people at home Schedule time ahead by
phone or stop by and
schedule more
convenient time
People may not want to Use the skills you learned
invite a stranger into their in interviewer training to
home gain trust
Costly and time-intensive Have someone on staff
method of interviewing train others on
interviewing techniques;
carpool; set time limits

122. Lessons Learned
1. Study community demographics and
characteristics before you interview
2. Train interviewers before an immediate
need
3. People like to tell you their stories- could
lead to relevant information

123. Telephone Interviews
2004 E. coli Outbreak Investigation

124. E. coli Outbreak Investigation
Telephone Interviews
• Illness onset October - November 2004
• Geographically dispersed cases in multiple
states
• Case-control study
• Train-the-trainer, interviewer

125. E. coli Outbreak Investigation
Telephone Interviews
• Between 3 and 6 interviewers
• Calls made between 3 p.m. and 8 p.m.
• Quality control with one central interviewing
location
• News coverage piqued people’s interest in the
outbreak investigation

126. Lessons Learned
1. Practice reading through the questions and
conducting an interview
2. The media can be your friend
3. Use an introductory script to relate the purpose
of the phone call to the individual quickly
– Identify and legitimize the interviewer
– State reasons for conducting the survey
– Assure that responses will be confidential

127. Summary
[Face-to-face] [Telephone]
Community Assessment Outbreak Investigation
– Establish rapport – News coverage helped
in recruiting people to
participate
– Identify people in a
small geographic area
– Widely distributed
sample
– Assess the environment
of the area
– We had the phone
numbers of all the
people who pre-
bought tickets

128. Question and Answer
Opportunity

129. Session Summary

130. Session Summary
• Questionnaire design and interview
methods are interrelated in the overall
process of an outbreak investigation.
• The primary purpose of interviews in
outbreak investigations is to collect data
for case identification, risk factor
identification, or hypothesis generation.

131. Session Summary
• Interview methods can be interviewer administered
(face-to-face or telephone) or self administered (mailed,
emailed, or Web-based). There are advantages and
disadvantages to employing either method.
• Sampling is the systematic selection of a representative
portion of the larger source population to be interviewed.
If the purpose of your study is to determine the point
source of infection, you may be able to interview a
smaller sample; if the purpose of your study is to
calculate an attack rate, you may need to interview a
larger sample.

132. Session Summary
• Survey response rates measure the percentage
of your sample that has participated in your
survey. Average response rates vary from as
little as 56% for mailed surveys to 75% for face-
to-face surveys.
• Non-response to surveys can be a result of no
one being home, refusal to participate, or
individual inability to participate (e.g., because of
a language barrier or physical or mental
condition).

133. Session Summary
• Survey data collection error is a result of
both bias and variance in the interview
process.
• Interviewer error can be prevented with
adequate interviewer training and the
standardization of survey instruments.

134. Session Summary
• Develop and distribute an interviewer manual to
provide interviewer support. Such
documentation reduces error and enhances the
quality of data collected.
• Sound interviewing procedures include: reading
questions exactly as they are worded; probing
inadequate answers; recording answers without
interviewer discretion; and maintaining rapport
with respondents.

135. Next Session November 3rd
1:00 p.m. – 3:00 p.m.
Topic: “Analyzing Data”

136. References and Resources
1. American Statistical Association (1997). What Is a
Survey? More About Mail Surveys. Alexandria, VA:
Section on Survey Research Methods, American
Statistical Association.
2. American Statistical Association (1997). What Is a
Survey? How to Collect Survey Data. Alexandria, VA:
Section on Survey Research Methods, American
Statistical Association.
3. Centers for Disease Control and Prevention (2005).
Outbreak Management System Demonstration Web
site.
http://www.cdc.gov/phin/software-solutions/oms/index.html
.

137. References and Resources
4. Fowler, F. and Mangione, T. (1990). Standardizing
Survey Interviewing. Newbury Park: Sage
Publications.
5. Gregg, M. (ed). (1996). Field Epidemiology. Oxford
University Press.
6. Holstein, JA and Gubrium, JF. (1997). Active
Interviewing. In Silverman, D. (Ed.) Qualitative
Research: Theory, Method, and Practice. London:
Sage Publications, pp. 113-129.
7. Last, J.M. (2001). A Dictionary of Epidemiology: 4th
Edition. Oxford University Press: New York.

138. References and Resources
8. Levy, P. and Lemeshow, S. (1991). Sampling of
Populations. John Wiley & Sons.
9. Ramsey, S. et al (2005). Using GIS and GPS to
Improve Public Health Response. Guilford County, NC
Health Department Public Health Regional
Surveillance Team 5.
10. Rubin, HJ and Rubin, IS. (1995). Interviews as Guided
Conversations. Qualitative Interviewing: The Art of
Hearing Data. Sage Publications, pp. 1-16, 122-144.
11. Salant, P. and Dillman, D. (1994). How to Conduct
Your Own Survey. John Wiley & Sons.

139. References and Resources
12. Stehr-Green, J.K. (2002). Gastroenteritis at a University in
Texas: Case Study Instructor’s Guide. Atlanta, GA: U.S.
Department of Health and Human Services, Public Health
Service, Centers for Disease Control and Prevention.
13. U.S. Census Bureau (2005). Profile of Selected Housing
Characteristics by State: Census 2000 Summary File 3 http
://factfinder.census.gov/servlet/QTTable?_bm=n&_lang=en&qr_name=D
14. Weiss, R.S. (1994). Learning from Strangers: The Art and Method
of Qualitative Interview Studies. New York: The Free Press.
15. Wiggins, B. and Deeb-Sossa, N. (2000). Conducting Telephone
Surveys. Chapel Hill, NC: Odum Institute for Research in Social
Science.