Sampling and types of sampling presentation PPT.pptx

SAMPLING TECHNIQUES
PREPARED BY :
Abhinav Bhatt

TERMINOLOGY USED IN SAMPLING�
SAMPALE:
Sample may be defined as representative unit of a target population, which is to be worked upon by researcher during their study.
SAMPLING:
Sampling is the process of selecting a representative segment of the population under study.



POPULATION:
Population is the aggregation of all the units in which a researchers is interested. In other words, population is the set of people or entities to which the results of a research are to be generalized.

TARGET POPULATION
A Target population consists of total number of people or objects which are meeting the designated set of criteria.




SAMPALING DESIGN
The formal plan specifying a sampling method, a sample size, and procedures for resulting subjects.

SAMPLING FRAME
It is a list of all the elements or subjects in the population from which the sample is drown. Sampling frame could be prepared by the researcher or an existing frame may be used.




SAMPALING ERROR
There may be fluctuations in the values in the values of statistics of characteristics from one sample to another ,or even those drawn from the same population.
 
SAMPALING BIAS
Distortion that arises when a sample is not representative of the population from which it was drawn.

SAMPLING PLAN
The formal plan specifying a sampling method, a sample size, and the procedure of selecting the subjects. 
PURPOSES OF SAMPLING

ECONOMICAL
In most cases it is not possible and economical for researchers to study an entire population, with the help of sampling, the researcher can save lots of time, money and resources to study a phenomenon .there for sampling provide an economic option for the researcher to generate the empirical evidences.
 
IMPROVED QUALITY OF DATA
It is a proven fact that when a person handles fewer amounts the work or fewer numbers of people, than it is easier to ensure the quality of outcome. Similarly in research .when a researcher is handling the information from only a part of the population under study, it is easier to maintain the quality of research work, which would not be possible in case the entire population was involved.


QUICK STUDY RESULTS
Studying an entire population itself will take a lot of time, and generating research result of a large mass will be almost impossible as most research studies have time limits. But with a sample, it is possible to generate study results faster, which is the one of the important objectives of every researcher. 
PRECISION AND ACCURACY OF DATA
Conducting a study on an entire population providers researchers with voluminous data, and maintaining precision of that data beco

1. SAMPLING TECHNIQUES PREPARED BY : Abhinav Bhatt

2. TERMINOLOGY USED IN SAMPLING SAMPALE: Sample may be defined as representative unit of a target population, which is to be worked upon by researcher during their study . SAMPLING: Sampling is the process of selecting a representative segment of the population under study.

3. POPULATION: Population is the aggregation of all the units in which a researchers is interested. In other words, population is the set of people or entities to which the results of a research are to be generalized. TARGET POPULATION A Target population consists of total number of people or objects which are meeting the designated set of criteria.

4. SAMPALING DESIGN The formal plan specifying a sampling method, a sample size, and procedures for resulting subjects. SAMPLING FRAME It is a list of all the elements or subjects in the population from which the sample is drown. Sampling frame could be prepared by the researcher or an existing frame may be used.

5. SAMPALING ERROR There may be fluctuations in the values in the values of statistics of characteristics from one sample to another ,or even those drawn from the same population.   SAMPALING BIAS Distortion that arises when a sample is not representative of the population from which it was drawn. SAMPLING PLAN The formal plan specifying a sampling method, a sample size, and the procedure of selecting the subjects. 

6. PURPOSES OF SAMPLING

7. ECONOMICAL In most cases it is not possible and economical for researchers to study an entire population, with the help of sampling, the researcher can save lots of time, money and resources to study a phenomenon .there for sampling provide an economic option for the researcher to generate the empirical evidences.   IMPROVED QUALITY OF DATA It is a proven fact that when a person handles fewer amounts the work or fewer numbers of people, than it is easier to ensure the quality of outcome. Similarly in research .when a researcher is handling the information from only a part of the population under study, it is easier to maintain the quality of research work, which would not be possible in case the entire population was involved.

8. QUICK STUDY RESULTS Studying an entire population itself will take a lot of time, and generating research result of a large mass will be almost impossible as most research studies have time limits. But with a sample, it is possible to generate study results faster, which is the one of the important objectives of every researcher .   PRECISION AND ACCURACY OF DATA Conducting a study on an entire population providers researchers with voluminous data, and maintaining precision of that data becomes a cumbersome task while carrying a study on part of the population (sample) helps the researcher to generate more precise data, where the formulation of the interpretations of the data becomes much easier, it is always easy to establish better report with a sample and thus to collect more accurate data. Thus a simple helps to generate precise and accurate data in a research study .

9. CHARACTERISTICS OF GOOD SAMPLE It should be representative of the population. It should free from the error due to bias, deliberated selection It should be have adequate and appropriate size. No substitution and incompleteness  

10. SAMPLING PROCESS

11. IDENTIFYING AND DEFINING THE TARGET POPULATION The first step of the sampling process is the identification and defining the target population .target population consist of the total group of people or object which are meeting the designated set of criteria of interest of researcher. Target population is the aggregated of cases about which are researcher would generalized the information DESCRIBE THE ASSESSABLE POPULATION AND ANSURING SAMPLING FRAM It is not always possible to have assessed of each subject included in target population. There for researcher must establish a description about the assessable population of, which is readily available for researcher .after establish a complete description of the assessable population, researcher must have a sampling farm available to select a sample from assessable population.

12. SPECIFY THE SAMPLING UNIT The researcher must establish the specific inclusion and exclusion criteria to select a particular sampling unit .specifying the sampling unit the help the researcher the eliminate the confusion while the selection of the sample SPECIFYING THE SAMPLE SELECTION METHOD It is the one of the important stage of sampling process where researcher decide whether sample will be drawn from the population by using probability and non probability sampling technique .selection of the specific method for selection of the sample depend on several factor such type of population, kind of phenomenon under study, an availability of resources of and knowledge of researcher.

13. DETERMINING THE SAMPLE SIZE It is very essential to determine to size of the sample, so that the researcher can plan the implementation of the sampling process accordingly. SPECIFYING SAMPLING PLAN Before selection of particular sample the researcher must have a final sampling plan, so that sampling process can be implemented without any undo problems. SELECTING THE DESIRE THE SAMPLE A finally research drawn a representative sample from the assessable population, which required the implementation of the plan the sampling process. And ultimately select a representative part of the population, which is used by the researcher for the data collection in research study .

14. TYPES OF SAMPLING TECHNIQUES

15. FACTOR INFLUENCING SAMPLIN PROCESS

16. NATURE OF THE RESEACHER INEXPERIENCED INVESTIGATOR If the investigator lacks adequate knowledge and experience about the conditions of the research and methodology to be applied in research process, the sample selection may be adversely get affected. LACK OF INTREST Lack of the self motivation and appreciation for carrying out tasks or establishing research methodology on the part of the researcher also effects the drawing of the sampling.

17. LACK OF HONESTY : Lack of honesty will affect sampling process in research. Researcher should be honestly involved in each step of the researcher process. INTENSIVE WORKLOAD : Lack of adequate resources and ability to carry out the research process results in inadequate selection and application of all resources, which results in adverse handling of research process including the sampling process. INADEQUATE SUPERVISION : There should be adequate supervision of the research activity to ensure the appropriate implementation of the research process including the sampling process.

18. NATURE OF THE SAMPLE INAPPROPRIATE SAMPLING TECHNIQUE : If a researcher fails to choose an appropriate a sampling technique, the whole sampling process may get affected . SAMPLE SIZE : Very large samples become heterogeneous and do not exhibit characteristics of whole population in general; also there are always chances of a biased sample. If sample is too small, a researcher may not be able to generalize the study findings to the whole population. DEFECTIVE SAMPLING FRAME : Defective sampling frame leads to faulty sampling process. Researcher should have adequate knowledge about population under study to have an appropriate sampling frame .

19. CIRCUMSTANCES LACK OF TIME : Adequate time should be available with the researcher to have adequate planning and implementation of the sampling process. The sampling process gets adversely affected . LARGE GEOGRAPHIC AREA : A large geographic area needs lots of time and resources’ to accomplish the sampling process. In addition, large geographical area can also lead to mental and physical exhaustion and thus the sampling process can get adversely affected .

20. LACK OF COOPERATION : During sampling process, researcher needs cooperation from competent authorities as well as from the study subjects. In the absence of cooperation of the requisite and study subjects, the sampling process may be adversely affected . NATURE CALAMITIES : Sometimes the sampling process is affected by natural calamities such as floods and other natural disasters, deaths or other environmental constrains.

21. PROBLEM OF SAMPLING

22. SAMPLING ERRORS : sampling error is the deviation of the selected sample from the true characteristics, traits, behaviors', qualilities or figures of the entire population .sampling process error occurs because researcher draw different subject from the same population, but still the subjects have individual differences .a sample, it is only a subset of the entire population; therefore, there may be difference between the sample and population.   LACK OF SAMPLE REPRESENTATIVENESS Selection of a representative sample is not an easy task; further, it become more difficult when population under study is heterogeneous and sampling process is carried out in the absence of consideration of the nature of the population.

23. DIFFICULTY IN ESTIMATION OF SAMPLE SIZE There is lack of availability of the population parameters, especially in our own scenario .in the absence of population parameters, it becomes very difficult to estimate the sample size .studies connected on undetermined sample size do not facilitate to generalize the finding for the particular population.   LACK OF KNOWLEDGE ABOUT THE SAMPLING PROCESS It is generally observed that researchers usually carry superficial knowledge about the sampling method and sampling process that leads to poor sample selection and ultimately effects the study results.   LACK OF RESOURCES Resource allocation especially for nursing research studies is very poor in a country like India, where it becomes very difficult for a researcher to draw a representative sample in absence of adequate resources .

24. LACK OF COOPERATION On several occasions it is observed that study subjects did not cooperate with researcher, which ultimately affects the sampling process and creates a problem for a researcher. for example ,a researcher selected a sample , with sample random sampling and found that several subjects are not interested to participate in study that ultimately disturbs the sampling process causes an addition burden to the researcher . LACK OF EXISTING, APPROPRIATE SAMPLING FRAMES FOR LARGER POPULATION It is generally observed that in developing countries including India it is very difficult to get existing sampling frames, which generally leads to problems in sampling process, for example, a nurse researcher is interested in sample selection from nurses presently practicing in Punjab, but Punjab nurses licenses, and therefore one cannot get a list of registered nurses presently practicing as nurses in Punjab.

25. CALLOUS APPROACH OF THE RESEARCHER TOWARDS SAMPLING PROCESS; Generally it is observed that researchers pay very little attention for appropriateness of the sampling method for a particular phenomenon under study. Further they casually chose a particular type of sampling technique to select a sample rather than an effective sampling process plan .

26. ADVANTAGES OF SAMPLING   1. Very accurate. 2. Economical in nature. 3. Very reliable. 4. High suitability ratio towards the different surveys. 5. Takes less time. 6. In cases, when the universe is very large, then the sampling method is the only practical method for collecting the data.

27. DISADVANTAGES OF SAMPLING 1. Inadequacy of the samples. 2. Chances for bias. 3. Problems of accuracy. 4. Difficulty of getting the representative sample . 5. Untrained manpower. 6. Absence of the informants. 7. Chances of committing the errors in sampling.