Northern
Ireland Crime Survey
Methodology
A
systematic random sample of 6,750 addresses is selected each year to
take part in the Northern Ireland Crime Survey. The addresses are
randomly selected from a database of domestic addresses from
the Land and Property Services (LPS). The LPS addresses are
sorted by district council and ward, so the sample is effectively
stratified geographically. People living in institutions (though not
in private households in such institutions) are excluded.
The
addresses are divided into batches and are issued to a panel of
interviewers on a monthly basis. The interviewers will call at each
address in their assignment over the month to conduct the interview.
One
person (aged 16 or over) from each address is chosen at random to be
interviewed. It is important
to have a strictly random selection, so that the results reflect the
experiences and attitudes of the whole population. For the same reason, it is very important
that the selected person agrees to take part. The LPS list is a list
of addresses only and has no information about the people who are
living at an address. This means that the interviewer has to collect
some information about the number of people who live at the address
before they can choose the selected respondent. This involves listing
all members of the household who are eligible for inclusion in the
sample: that is, all persons currently aged 16 or over living at the
address. From this listing of eligible adults, the
interviewer’s computer randomly selects one adult. This person,
the selected respondent, is then asked to complete the interview.
|
