sampling and its process. pptx

The process of using a small number of items or parts of larger population to make a conclusions about the whole population.

Sampling is the process of selecting representative units from an entire populations of a study .

Sampling is a technique of selecting a subset of the population.

EXAMPLE – While cooking rice to see whether the rice are cooked or not we never see each and every grain of rice. only a sample of rice grain is checked to make the decision regarding the cooked or the uncooked rice
A sample should be reliable.
A sample should be economical.
A sample should be goal oriented.
A sample should be appropriate in size.
A sample should be free from bias and errors.
A sample should be true representation of population.
NATURE OF THE RESEARCHER-
Inexperienced investigator
Lack of interest
Lack of honesty
Lack of adequate resources
Inadequate supervision
NATURE OF SAMPLE –

Inappropriate sampling technique
Sample Size
Defective sampling Frame

1. SAMPLING & PROCESS MS. POOJA SEN M.SC NURSING ( PSYCHIATRIC )

2. TERMINOLOGY SAMPLE- A representative unit of a target population. TARGET POPULATION – It is the total collection of elements about which we wish to make some inferences. ACCESSIBLE POPULATION- the portion of the target population that the researcher can access. SAMPLING – The process of selecting a part of population. SAMPLE SIZE- The number of people in the selected sample . SAMPLING FRAME – The list of individual or people included in the sample . SAMPLING TECHNIQUE – It refers to the technique or procedure used to select members of the sample. SAMPLING ERROR – Fluctuations in the values of the statistics of characteristics from one sample to another .

3. SAMPLING DEFINITIONS The process of using a small number of items or parts of larger population to make a conclusions about the whole population. Sampling is the process of selecting representative units from an entire populations of a study . Sampling is a technique of selecting a subset of the population . EXAMPLE – While cooking rice to see whether the rice are cooked or not we never see each and every grain of rice. only a sample of rice grain is checked to make the decision regarding the cooked or the uncooked rice

4. CHARCTERSTICS OF GOOD SAMPLING A sample should be reliable. A sample should be economical. A sample should be goal oriented. A sample should be appropriate in size. A sample should be free from bias and errors. A sample should be true representation of population.

5. FACTORS INFLUENCING SAMPLING 1. NATURE OF THE RESEARCHER- Inexperienced investigator Lack of interest Lack of honesty Lack of adequate resources Inadequate supervision

6. FACTORS INFLUENCING SAMPLING 2. NATURE OF SAMPLE – Inappropriate sampling technique Sample Size Defective sampling Frame

7. FACTORS INFLUENCING SAMPLING 3. CIRCUMSTANCES – Lack of time Large geographical area Lack of co-operation Natural Calamities

8. SAMPLING PROCESS IDENTIFY THE POPULATION OF INTEREST DEFINE TARGET POPULATION DEFINE THE ACCESSIBLE POPULATION CONSTRUCT SAMPLING FRAME SPECIFY THE SAMPLING UNIT DETERMINE THE SAMPLE SIZE CHOOSE THE SAMPLING TECHNIQUE SELECT SAMPLE AS PER THE CHOSEN SAMPLING TECHNIQUE

9. IDENTIFY THE POPULATION OF INTEREST - Population is a term usually makes us to think of the people in our town ,region, state or country and bring into mind their respective characteristics such as gender age, marital status, religion. DEFINE TARGET POPULATION – TARGET POPULATION – is the whole group of people or object to which the researcher wishes to generalize the study findings and which meet a criterion. DEFINE THE ACCESSIBLE POPULATION ACCESSIBLE POPULATION – It is usually not possible to include the entire target population in the study because of various factors like manpower ,time ,money. The members of the populations may be unwilling to participate .So we need to take a part of the population which is practically accessible to the researcher, this is called accessible population. It subset of the target population STEP – 1 IDENTIFYING THE POPULATION

10. CONSTRUCT SAMPLING FRAME Once the definition of accessible population is clear, the researcher should be prepare the sampling frame .It is the list of all the members of the population from which the sample is taken A sampling frame is not as large as a population, but it is still a big group of prople .It may not be possible to study every single unit of the accessible population, so researcher need to draw the sample from the sampling frame using some technique which is the next step of the sampling process. Example – If the study is to be conducted on nurses of hospital then list of all the nurses working in that particular hospital will be the sampling frame .An ideal sampling frame enlist the names of its elements only once . STEP – 2 CONSTRUCT SAMPLING FRAME

11. SPECIFY THE SAMPLING UNIT The researcher must establish the specific inclusion and exclusion criteria to select a particular sampling unit .it is a basic unit which contains a single elements or a groups of elements of the population to be sampled .specify the sampling units helps the researchers to eliminate the confusion while the selection of the sample. STEP – 3 SPECIFY THE SAMPLING UNIT

12. STEP – 4 Determine the sample size DETERMINE THE SAMPLE SIZE It is very essential to determine the size of sample ,so that the researcher can plan the implementation of the sampling process accordingly .The total number of subjects/ units / observations in the sample constitutes the sample size if the study . It is represented by n and N refers to the total number of units in the entire target population or population size . The ratio of n/ N is Called Sampling Fraction.

13. CHOOSE THE SAMPLING TECHNIQUE It is one of the important stages of the sampling process ,where the researcher decides weather sample will be drawn from the population by using probability and non probability sampling techniques. Selection of the specific method for selection of the sample depends on several factors ,such as types of population ,kind of phenomenon under study and availability of resources and knowledge of the researcher. STEP – 5 Choose Sampling Techniques

14. STEP – 6 Select Sample as per the chosen sampling technique SELECT SAMPLE AS PER THE CHOSEN SAMPLING TECHNIQUE Once we know the population, sampling frame ,sampling method and sample size ,we can use all that information to choose the sample for the study. This is the final step in the sampling process ,which implementing the sampling plan to select a sample required for the survey. The actual selection of the sample elements is carried out in this stage .