1. Sampling Procedures Cs 12
Objectives
Define Terms to Sampling Procedures
Specify the advantages & disadvantage
of Sampling
Define the two approach of Sampling

2. Sampling Procedure: is the way the researcher select the elements to be investigated in the research study
Terms Related to Sampling procedure
Population: Entire set of elements, people, events, behaviors, substances, that could possibly be considered for the study
Called Target Population, from which Sample was taken
Element: Individual units of a population, can be a person, event, behavior, substance or any single measurement unit of a study
An elements of a persons called SUBJECT

3. Terms Related to Sampling procedure
Sampling Criteria: Standards or rules the researcher set up to determine what elements will be included in the population and sample
(Characteristics of the Element)
Sampling: Selecting a group of elements from total population which will be studied in the research
(Process of Making a Selection)
Sample: Group of elements selected from
the total population to be studied in the research

4. Terms Related to Sampling procedure
Randomization: Random selected of a representative sample from the target population, each sample has an equal opportunity to be chosen Randomly
Sampling Frame: Listing every member of the target population according to sampling criteria to define a membership
This listing called Sampling Frame

5. Terms Related to Sampling procedure
Accessible Population: Random Selection is ideal, Time & Coast factors limited the possibility of achieving realistic & idealistic
An accessible population is the portion of the target population to which the researcher has reasonable access
Sample should be obtain from the accessible population
Representative: Sample must be like the target population as many way of possible in relation to variables to be examined & other factors influenced the study variables

6. Advantage of Sampling
Economic & Efficient to work with small group of elements, does not require many resources
Possible to obtain reasonable accurate information

7. Disadvantages of Sampling
Sampling Bias refers to the systemic overrepresentation or underrepresentation of some segment of population in term of characteristic relevant to research question
Sampling Error

8. Approaches to Sampling
Reason to chose sampling approach:
To decrease Systemic bias
To decrease sampling error
To increase representativeness

9. Approaches to Sampling
Probability Sampling
Nonprobability Sampling

10. Probability Sampling
Probability: fact that every member (element) of the population has a probability higher than zero of being selected for the sample refereed as a Random Sampling
To obtain a Probability Researcher must:-
know every element in the population
Develop A Sampling Frame
Clearly define the population

11. Researcher Must have knowledge about each Strata
Probability Sampling
Simple Random Sampling: Elements are selected from the frame randomly
Stratified Random Sampling: First population is divided into two or more Strata or Subgroups to achieve representativeness
Such as: divided according to
Age, Race, Gender
Socioeconomic Status
Diagnosis
Researcher Must have knowledge about each Strata

12. NonProbability Sampling Characteristics
Not every element of population has an opportunity for selection in a sample
No Sampling Frame
Parameters of population may not be known
No clearly identification for population
Hypothetically population is defined

13. NonProbability Sampling
Accidental Sampling: Convenience Sampling or Incidental Sampling
Subject included in the study because they
happened to be in the right place at the right
time
To avoid Multiple biases strategies may be used
In expensive
Accessible
Require less time
More easy than probability

14. NonProbability Sampling
2. Quota Sampling:
Use an accidental sampling technique with an added feature
a strategies to ensure the inclusion of a subject types that are likely to be underrepresentative in the accidental type
Offers an improvement on accidental type
To decrease the biases

15. NonProbability Sampling
3. Purposive Sampling: Judgmental Sampling Conscious Selection of a certain sample to be studied
Depend on the Precision of the researcher's judgment

16. Sample Size
General Rules to select Sample Size Make Size as LARGE as possible
Factors should be considered in making decision about sample size:-
Type of the study
Number of Variables
Sensitivity of the measurement tools
Data analysis techniques
Expected effect size