SAMPLING IN FOOD SECURITY ASSESSMENT

Kayw Zaw TunProgramme Assistant (GIS)

WFP

PROBABILITY SAMPLING

Simple random sampling Systematic sampling Stratified sampling Cluster sampling Multi-stage sampling

Non-Probability sampling Purposive samplingConvenience sampling

STRATIFIED (RANDOM) SAMPLING

A A B B B BA A A A C C C C A A C C C C

Divide the population into homogeneous sub-groups.Select sub-samples from each sub-group. (If one selects them in proportion to the size of the sub-group, the sample does need to be weighted later.)Maintains representation with small samples being even when the population is quite large.Ensures representation if the population is highly heterogeneous and some groups might be left out of the sample.

Is cost-effective and time-saving.

Own production(food or cash

crop, livestock, fish farm)

Sales Cash income

Essential non-food expenditure

Employment Cash receipt

s

Food purchases

Food receipts

Household food access

Quantities retained for household’s own use

Trading

Gathering Fishing Hunting

Resource flows

Asset accumulation Non-essential expenditures

Quantities sold to generate income

Sources of food

Income used to purchase

food

Debts incurre

d

Expenditure

Non-agric. productio

n

Sources of

income

= Livelihood activities

Zoning in NRS

Landsat 7ETM +

Land Cover Classification

Agriculture Land and Non-

Agriculture Land

Distribution of River and Stream

Channel

Road Infrastructure

2 Miles Buffer from Coastal

Line

NRS Zones

SAMPLING

Calculation of sample size for Food Security profiling exercises

Calculation for Sample size N= 1.962 x (P)(1-P)

d2

1.96 = 95% confidence interval

P=Estimated prevalence

(50%)

d= desired precision ( 5%)

DEFF=Design effect

(1.5)

HH refusal5%

607

Township: Village-tract… ……………Villages ……. …………… Segment No.……..

Random start number: …………..

Sampling Interval= (total number of households) divided by (total hh to be visited) and then round the result = …………

Sr. of hh

Name of hh head

Name of spouse

# of HH membersSr. No. of sample hh

Remarks

Male Female Total

               

               

               

               

               

               

               

               

               

               

SYSTEMATIC SAMPLINGA list of individuals/households is numbered.The list is divided into ‘n’ equal sections (‘n’ being sample size).One unit is selected using SRS.Corresponding numbers (one from each) are taken from each section (e.g. if the sixth unit is chosen from the first section, then it should be taken from all the other sections).It is possible to list the population in a meaningful manner (such as putting each county together) and thus ensure samples are taken from each county.

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THNAK YOU