Sampling
- 1. Statistical data can be collected in two ways, 1-census method ; A census method is a study of every unit , everyone or everything in a population. 2-sampling method ; A small group is chosen deliberately or at random from the population.
- 2. A group of individuals , objects , or items from which samples are taken for research. Totality of the units of interest. Target population/universe ; the entire group of people or objects to which the researcher wishes to generalize the study finding.
- 3. Examples ; all people with AIDS , all pregnant teens , all school-age children with asthma. Accessible population ; the portion of population to which the researcher has reasonable access ; may be a sub-set of the target population.
- 4. Examples; all people with AIDS in Faisalabad city , all pragnet teens in Universities of New York city , all school – age children of Lahore city.
- 5. It contains a countable number of units or elements or individuals. In finite population the number of individuals or units is known and limited. Examples ; number of student of GPCSF , population of inhabitants of Pakistan.
- 6. Infinite population ; It contains an infinite or unlimited or uncountable number of individuals or units. Examples; points of a line , number of stars in the sky.
- 8. The technique or procedure used in selecting a sample from the population which would be representative of whole population
- 9. The complete list or map or some other record of all sampling units of a population. Examples ; complete list of the households of a colony , the list of employees of a factor. 1-it should be free from duplication. 2-it should not be out of date. 3-it should not be incomplete.
- 10. All the units or items constituting or forming the population is called sampling unit. The units selected for investigation out of the sampling units to form a sample are known as sample units.