A PRESENTATION ON “QUOTA SAMPLING”

Presented By: (ARYAN’S) Abishek Kumar Ajit Kumar Gaganjit singh Praveen Kumar Sumanto Sharan Swapnil Adahalli

SAMPLING Sampling may be defined as the selection of some part of an aggregate or totality on the basis of which a judgement or inference about the aggregate or totality is made.

It is the process of obtaining information about an entire population by examining only a part of it.

The process of selecting sample from the population is called sampling.

WHY SAMPLE ?

Saves moneySaves timeA sample can be more accurate; it has fewer “nonsampling” errors than a census.

TYPES OF SAMPLING

PROBABILITY SAMPLING

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

NON-PROBABILITY SAMPLING

Deliberate sampling Quota sampling Sequential sampling Snowball sampling Panel sampling Shopping mall sampling

QUOTA SAMPLING

In quota sampling the selection of the sample is made by the interviewer, who has been given quotas to fill from specified sub-groups of the population.

For example, an interviewer may be told to sample 50 females between the age of 45 and 60.

QUOTA SAMPLING

In quota sampling the selection of the sample is non-random.

For example interviewers might be tempted to interview those who look most helpful. The problem is that these samples may be biased because not everyone gets a chance of selection. This random element is its greatest weakness and quota versus probability has been a matter of controversy for many years

CONT…..

Pre-plan number of subjects in specified categories (e.g. 100 men, 100 women) In uncontrolled quota sampling, the subjects chosen for those categories are a convenience sample, selected any way the interviewer chooses

In controlled quota sampling, restrictions are imposed to limit interviewer’s choice No call-backs or other features to eliminate convenience factors in sample selection

QUOTA SAMPLING…..

Quota Sampling Most commonly used non-probability method Select a sample on specified criteria (usually to make similar to target population)

Pick people to fill quota on characteristics especially important to research goals

Example: Studying political issues, set quota on party identification

Sample of 200 Registered Republicans 50% Sampled Republicans 100 Registered Democrats 40% SampledDemocrats 80 Registered Independents 10% SampledIndependents 20

Using quotas for several criteria

Race/Ethnicity Black White Latino/a Asian Gender Gender Gender Gender

Political M F M F M F M F Affiliation Democratic Republican Independent

Quick and cheap to organise

Advantages

Not as representative of the population as a whole as other sampling methods Because the sample is non-random it is impossible to assess the possible sampling error

Disadvantages

Quota Vs Stratified Sampling

QUOTA SAMPLING STRATIFIED SAMPLING

In Quota Sampling, interviewer selects first available subject who

meets criteria: is a convenience sample.

In Stratified Sampling, selection of subject is

random. Call-backs are used to get that particular

subject

Highly controlled quota sampling uses probability sampling down to the last

block or telephone exchange

Stratified sampling without call-backs may

not, in practice, be much different from quota

sampling.

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