Behavioural Surveillance Surveys - The Wisdom of Whores

Alternative to “in-class” sampling
for school youth
If “in-class” data collection in schools is not
possible, it will be necessary to obtain data
from students in non-classroom settings.
Although it may be possible to schedule
appointments with individuals or groups of
students to be interviewed either before or
after school, the most feasible approach is
likely to be to conduct “intercept” interviews
with individual students at strategically chosen
locations (e.g., outside of classrooms or in
cafeterias, lunch rooms, or other common
areas where students congregate). Either
self-administered questionnaires or personal
interviews may be used to gather the survey
data, depending upon whether there is a
convenient place available for students to
sit down and complete a self-administered
questionnaire. Irrespective of the data
collection strategy used, it is important that
steps be taken to ensure that the sample is
sufficiently well spread out across students
of different grades/levels.
Selecting students when entering or leaving the
classroom
If students are to be interviewed as they
enter and/or leave class, the classes/sections
from which sample students are to be drawn
should be chosen using a systematic-random
selection procedure similar to that used in
selecting classes/sections for in-class data
collection (see Figure 10).
The number of classes/sections to be
chosen will depend upon the target sample
size for the survey and the number of students
it is expected can be interviewed before and
after each class. For example, if the target
sample size for a survey were n=300 students
and it was anticipated that n=6 students could
be interviewed by the team, before/after each
class per day, n=50 classes/sections might be
chosen. Alternatively, n=25 sample classes/
sections could be chosen if more interviewers
could be deployed simultaneously and each
could complete more interviews before/after
each class.
Selecting students from common areas
If student survey respondents are to be
recruited from common areas, a time-location
strategy, similar to the one described for
floating populations (sex workers, MSM and
IDU) in Chapter 4 might be employed.
In the case of school surveys of youth,
the time-location PSU’s would be defined as
the common-areas where students congregate
at different time intervals. For example,
if a school cafeteria or lunch room that is
open three hours per day is to be used as
the location from which to choose survey
respondents, each day-hour of operation might
be used as a PSU. In this case, there would
be 15 PSU’s per week per school (3 one-hour
segments per day * 5 days per week).
PSU’s should be chosen using systematic
sampling. The number of PSU’s to be chosen
will depend upon the target sample size for
the survey and the number of students it is
expected can be interviewed during each time
segment. For example, if the target sample
size for a survey were n=300 students and
it is anticipated that n=10 students could be
interviewed during each time segment, n=30
segments might be chosen.
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A PPEN DI X 3 B EHAV I OR A L SURV EI L L A NC E S U R V EY S