Sampling techinques
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This document discusses different types of sampling techniques, including non-probability and probability sampling. Non-probability sampling techniques include convenience, judgmental, snowball sampling, while probability sampling includes simple random sampling, systematic sampling, stratified sampling, and cluster sampling. The document provides details on each technique, including their objectives, processes, and uses.
Sampling techinques
- 1. Dr S S N Raju Indukoori SAMPLING TECHNIQUES
- 2. TYPES OF SAMPLING TECHNIQUES DR RAJU INDUKOORI 2 Based on Restriction 1) Unrestricted 2) Restricted Based on Probability 1) Non Probabilistic Sampling 2) Probabilistic Sampling
- 3. NON PROBABILITY SAMPLING DR RAJU INDUKOORI 3 • Unrestricted: It is convenience sampling, as a choice of sample • Restricted 1) Purposive or Judgmental Sampling a. Deviant Case: Avoid Problematic b. Quota Sampling: Group of small size c. Ad hoc Quotas: Limited size within group 2) Snowball Sampling: Referrals
- 4. NON PROBABILITY SAMPLING DR RAJU INDUKOORI 4 Reasons to use • Procedure satisfactorily meets the sampling objectives • Lower Cost • Limited Time • Not as much human error as selecting a completely random sample. • Total list population not available
- 5. PROBABILITY SAMPLING DR RAJU INDUKOORI 5 • Unrestricted : Simple random • Restricted : Complex Probability Sampling 1. Systematic Sampling 2. Stratified Sampling • Proportionate • Disproportionate 3. Cluster Sampling. 4. Double / Multiphase Sampling.
- 6. SIMPLE RANDOM SAMPLING DR RAJU INDUKOORI 6 • Unrestricted and provide a known non zero probability. • Purest form of probability Sampling SizePopulation SizeSample SelectionofyProbabilit
- 7. COMPLEX RANDOM SAMPLING DR RAJU INDUKOORI 7 1. Systematic Sampling 2. Stratified Sampling • Proportionate • Disproportionate 3. Cluster Sampling. 4. Double / Multiphase Sampling.
- 8. 1. Systematic Sampling DR RAJU INDUKOORI 8 • Every kth element is sampled. • Skip interval is known as kth element. • Simple and flexible Process • Identify, list and number the elements in the population skip interval (k) • Identify the random start • Draw a sample by choosing every kth entry SizeSample SizePopulation intervalskipk
- 9. 2. Stratified Sampling DR RAJU INDUKOORI 9 • Population divided into sub categories (strata). • Strata is selected based on some criteria • Strata is homogeneous internally and heterogeneous externally. • Elements in strata are selected randomly
- 10. 2. Stratified Sampling DR RAJU INDUKOORI 10 Objective is to 1. increase sample’s statistical efficiency 2. Provide adequate data for analyzing strata 3. enable different research methods and procedures to be used in different strata. Types • Proportional to population • Disproportional to population
- 11. 3. CLUSTER SAMPLING DR RAJU INDUKOORI 11 • Population divided into sub groups (Clusters). • Clusters are selected randomly • Clusters are heterogeneous internally and homogeneous externally.
- 12. 3. Cluster Sampling DR RAJU INDUKOORI 12 Objective is to increase economic efficiency. Types • Area Sampling for geographic area • Double / Sequential / Multiphase Sampling
- 13. TYPES OF SAMPLING TECHNIQUES DR RAJU INDUKOORI 13 Element of Selection Non Probability Probability Unrestricted Convenience Sampling Simple Random Restricted Judgment Sampling Deviant Case, Quota, Adhoc Quota Systematic Sampling Snow Ball Sampling Cluster Sampling Stratified Sampling Double Sampling