1. SAMPLING BY Dr. Ali K. Al-mesrawi

2. Definition of sampling Sampling is the process by which inference is made to the whole by examining a part. Sampling is the process of selecting units from a population of interest so that by studying the sample you can fairly generalize your results to the population from which the units were chosen

3. Meaning of sampling The process of testing some data based on a small sample is called sampling. Eg: F rom a cup of tea, a tea-taster determines the quality of the brand of tea.

5. THE PURPOSE OF SAMPLING The purpose of sampling is to provide various types of statistical information of a qualitative or quantitative nature about the whole by examining a few selected units.

6. ADVANTAGES OF SAMPLING Greater economy Greater scope less time

7. TYPES OF SAMPLING 1.Probability sampling: Simple Random Sampling Systematic Random Sampling Stratified Random Sampling Cluster Or Multistage Sampling

8. SIMPLE RANDOM SAMPLING: In which each and every item has an equal chance of selection.

9. SYSTEMATIC RANDOM SAMPLING: In which one or two items are selected randomly, but other items are selected by adding the average sampling interval to the item selected randomly.

10. STRATIFIED RANDOM SAMPLING: It is the process of segregating the population into groups and select by systematic sampling method from each strata or cell.

11. CLUSTER SAMPLING: The population is divided into clusters like families and then simple random sampling is applied.

12. 2. CONVENIENCE SAMPLING: Convenience/ opportunity sampling. Purposive/ judgemental sampling Quota sampling Snowball sampling

13. CONVENIENCE SAMPLING: The process of including whoever happens to be available at the time. It also called “accidental” or “haphazard” sampling

14. JUDGEMENTAL (PURPOSIVE)SAMPLING: The process whereby the researcher selects a sample based on experience or knowledge of the group to be sampled.

15. QUOTA SAMPLING: A researcher gathers data from individuals possessing يمتلكون identified characteristics and quotas. حصص For example, an interviewer may be told to sample 200 females and 300 males between the age of 45 and 60.

16. SNOWBALL SAMPLING : The sampling procedure in which the initial respondents are chosen by probability or non- probability methods, and then additional respondents are obtained by information provided by the initial respondents

17. STEPS IN SAMPLING PROCESS STEP 1: Define the target population STEP 2: Identify the sampling frame STEP 3: Specifying the sampling unit. STEP 4: Selection of the sampling method. STEP 5: Determination of sample size. STEP 6: Specifying the sampling plan. STEP 7: Selecting the sample.

18. STEPS IN SAMPLING PROCESS

19. LIMITATIONS OF SAMPLING Errors due to sampling may be high for small administrative areas. Sampling may not be feasible for problems that require very high accuracy. Threats to Valid Sampling The population you want to generalize to is different from your sample The setting/place you want to generalize to is different from the place you conducted your study The time when you conducted your study was unsuitable

20. THANK YOU SO MUCH FOR YOUR Patience !!!