Module H6 Practical 3
Random and Stratified Sample Selection
1. In this exercise, imagine you are a livestock scientist and want to conduct a survey to
assess farmers’ knowledge of cattle diseases and the way in which farmers deal with such
diseases. This information is needed to develop extension materials about cattle diseases
and control methods.
Assume resources permit the study to be conducted in at most 5 districts. Assume also
that the only background information available to you consists of the information available
on page 3 of this handout. A map of Uganda showing the district locations is also available
(page 2) which may be helpful. The data of page 3 are available in the Excel workbook
named H6_data.xls in sheet CattleDiseases.
Your task for this exercise is to select a sample of districts where the survey will be
implemented, but resources dictate that you cannot visit more than 5 districts. Divide into
groups of 4 or 5 persons to discuss and answer the questions below. Some groups will be
invited to present their findings to the rest of the class.
(a) Consider two possible sampling approaches, i.e. using
(i)
Simple random sampling; or
(ii) Stratified random sampling.
Consider how you might choose the sample of districts through each of the above
sampling procedures, remembering that you do not have resources to sample more than 5.
For (ii), you will need to decide what stratification variable(s) to use. There are other
challenges, e.g. some types of information are not available for all districts. You will need
to discuss how to cope with this and whether you would need to make some assumptions
as a result.
(b) Is one method of sampling more appropriate than the other? If so, discuss why.
(c) Suppose you had time to seek out additional information before finalising your
sampling procedure. What would be the most important additions you might seek? How
would you anticipate using the extra knowledge?
SADC Course in Statistics
Module H2 Practical 3 – Page 1
Module H6 Practical 3
SADC Course in Statistics
Module H2 Practical 3 – Page 2
Module H6 Practical 3
Uganda districts with information concerning cattle
Source: M.O. Rwabwoogo – Uganda districts Information Handbook (2002 Edn.). Fountain Publishers, Kampala, Uganda
District
number
1
2
3
4
11171
District
number
29
Kumi
15000
Apac
41992
30
Kyenjojo
56000
Arua
120580
31
Lira
22268
Bugiri
22424
32
Luwero
27193
46835
33
Masaka
cattle ranching
528017
161278
34
Masindi
cattle ranching
51833
Mayunge
cattle keeping
91142
District name
Whether cattle feature in
Economic activities
Adjumani
5
Bundibugyo
6
Bushenyi
dairy farming
Number of
cattle
District name
7
Busia
28819
35
8
11000
22424
36
9
Gulu
Hoima
37
Mbale
Mbarara
10
Iganga
61157
38
Moroto
Moyo
Whether cattle feature in Economic Number of
activities
cattle
166723
607396
cattle ranching & dairy farming
11
Jinja
14031
39
12
Kabale
84280
40
Mpigi
cattle rearing
648986
21417
dairy farming
105482
13
Kabarole
58815
41
Mubende
cattle ranching & dairy farming
66835
14
Kaberamaido
4667
42
Mukono
dairy farming
78516
43
Nakapiripit
cattle rearing
170000
14460
44
Nakasongola
cattle rearing
58787
128648
45
Nebbi
54145
46
Ntungamo
Pader
15
Kalangala
16
Kampala
17
Kamuli
18
Kamwenge
19
Kanungu
14550
20
Kapchorwa
64738
47
48
21
Kasese
13637
49
Rakai
50
Rukungiri
51
Sembabule
52
Sironko
83376
35290
53
Soroti
23333
8674
54
Tororo
325341
Wakiso
103451
Yumbe
58760
22
Katakwi
23
Kayunga
24
Kibale
25
Kiboga
26
Kisoro
cattle rearing
39259
cattle ranching
27
Kitgum
cattle keeping
5000
55
28
Kotido
cattle rearing
400000
56
SADC Course in Statistics
Module H2 Practical 3 – Page 3
90044
cattle rearing
125627
3758
Pallisa
157888
cattle keeping
240487
dairy farming
28800
cattle herding and ranching
110469
Module H6 Practical 3
SADC Course in Statistics
Module H2 Practical 3 – Page 4