CRC 2015. English

territory. In each village sampled at the first level, the households were listed in order
to systematically draw 15 households at the second level. Then, the head/member of
the household above 18 years responded to the questionnaire.
In the first stage, the Primary Survey Units (villages / imidugudu) were selected
randomly using the SPSS software from the NISR database of all villages.
In the second stage, the systematic selection of households followed this procedure:
1) The list of all households was provided for each village with the total number of
households;
2) The numbers were summed up to obtain a final number equal to the total
households in the stratum;
3) In each stratum, the sample units were selected systematically, using the interval
of selection (I h
= Total number of households / units to be surveyed) and random
seed (Rh) obtained by multiplying the selected interval by a random number
between 0 and 1.
Thus, the first sample unit was identified by the random starting point; the second
sample unit corresponded to the random starting point plus the assigned step. The
following sample units were identified by adding multiple consecutive interval steps
to the cumulative sum, until the sample size is reached. In general, the i th sample unit
(S hi
) in stratum h can was selected as follows:
S hi
= R h
+ (i-1)I h
for i=1,2,….,n h
Where :
S hi
= number selected for the i th sample unit in stratum h
R h
= random selected for stratum h;
I h
= Interval Draw for stratum h;
n h
= number of sample units selected in stratum h.
Probability sampling
In each stratum, the sample selection was done independently from other strata. This
is due to the existence of sampling frames that are different from other strata. Thus,
the sampling probabilities are calculated for each level of estimation, i.e., for each
stratum. This requires prior determination of the probability of sampling at each
stage of sample selection.
6 Rwanda Citizen Report Card Survey 2015