Sampling & Types of Sampling
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The document outlines the concept of sampling in research, emphasizing its importance in obtaining accurate and representative data from a larger population. It describes various sampling methods, including simple random sampling, systematic sampling, stratified sampling, cluster sampling, convenience sampling, and snowball sampling. The session is facilitated by Zulfiqar Behan at Jamia Millia College of Education on January 27, 2016.
Sampling & Types of Sampling
- 1. Title: Sampling in research SLOs At the end of session participants will be able to Know types of sampling Application of sampling Venue: JamiaMillia College of Education Date: January 27, 2016 Time: 11:00 am to 12:00 pm Facilitator: Zulfiqar Behan zulfiqarbehan@yahoo.com
- 2. Sampling •Sampling is the process of selecting units (e.g., people, organizations) from a population of interest so that by studying the sample we may fairly generalize our results back to the population from which they were chosen. •Sample = a smaller group selected from the sample frame to participate in the research
- 3. A sample is “a smaller (but hopefully representative) collection of units from a population used to determine truths about that population” (Field, 2005) Why sample? Resources (time, money) and workload Gives results with known accuracy that can be calculated mathematically
- 5. Simple Random Sample Get a list or “sampling frame” a. This is the hard part! It must not systematically exclude anyone. Generate random numbers Select one person per random numbers
- 6. Simple Random Sample • Every subset of a specified size n from the population has an equal chance of being selected
- 7. SYSTEMATIC SAMPLING…… 7 As described above, systematic sampling is an EPS method, because all elements have the same probability of selection (in the example given, one in ten). It is not 'simple random sampling' because different subsets of the same size have different selection probabilities - e.g. the set {4,14,24,...,994} has a one-in-ten probability of selection, but the set {4,13,24,34,...} has zero probability of selection.
- 8. Stratified Random Sample 1. Separate your population into groups or “strata” 2. Do either a simple random sample or systematic random sample from there a. Note you must know easily what the “strata” are before attempting this b. If your sampling frame is sorted by, say, school district, then you’re able to use this method
- 9. STRATIFIED SAMPLING……. 9 Draw a sample from each stratum
- 10. Cluster Random Sampling • Similar to stratified sampling but the groups are selected for their geographical location • i.e. school children within a particular school. • The school is the cluster with the children being selected randomly from within the cluster
- 11. The Convenience Sample Find some people that are easy to find
- 12. 12 CONVENIENCE SAMPLING……. – Use results that are easy to get 12