Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Population and sample

9,819 views

Published on

Population and sample

Published in: Education
  • Be the first to comment

Population and sample

  1. 1. BY- Firoz qureshi Dept.psychiatric nursing
  2. 2.   Population the entire set of individuals or objects having some common characteristics selected for a research study. E.g. patients admitted to intensive care units.  Sample may be defined as representative unit of a target population, which is to be worked upon by the researchers during their study. INTRODUCTION
  3. 3.   “A population is a complete set of persons or objects that possess some common characteristics that is of interest to the researcher.”  The population for a study usually is described as being composed of two groups-  Target population  Accessible population POPULATION
  4. 4.   The target population which is also called the universe is composed of the entire group of people or objects to which the researcher wishes to generalize the findings of the study.  The target population consists of people or things that meet the designated set of criteria of interest to the researcher. TARGET POPULATION
  5. 5.   A researcher is interested in identifying the complication of DM typeII among people who have migrated to Ludhiana.  In this instance, the target populations are all the migrants at Ludhiana suffering with DM typeII. EXAMPLE
  6. 6.   It is aggregate of cases that confirm to designated criteria and are also accessible as subjects for study.  By identifying the group from which the study sample was chosen, the investigator about the conclusion of the generalizability of research findings. ACCESSIBLE POPULATION
  7. 7.   A research is conducted on the registered nurses (RN) working in Dayanand Medical College and Hospital (DMCH), Ludhiana.  In this case the population for this study is all RNs working in DMCH, but some some of them may be on leave and may not be accessible for research study. Therefore accessible population for this study will be RNs who meet the designated criteria and who are also available for the research study. EXAMPLE
  8. 8.   The criteria that specified the characteristics that people in the population must possess are sometimes referred as Eligibility Criteria or Inclusion Criteria.  Example-  To be eligible for a study on myocardial infection, the patient must be:  Hospitalized because of MI or coronary angiography. 1. Have no prior history of CAD. 2. Be older than 18 years of age. 3. Be in haemodynamically stable condition and free of pain for 24 hours. 4. Be oriented to person, place and time. 5. Able to speak or understand English. 6. The people may be defined to exclude who does not speak English. ELIGIBILITY CRITERIA
  9. 9.   Inclusion and Exclusion criteria for a study often reflects considerations other than a substantive or theoretical interest in certain types of people. The criteria for defining the population may reflect one or more of the following: 1. COSTS: some criteria reflects costs constraints. For example, when a non- English speaker people are excluded. This does not necessarily mean that the researcher is not interested in English speakers , but may rather reflect the fact that the researcher cannot afford to have translators. 2. PRACTICAL CONCERNS: There are other practical concerns such as difficulty in including people in rural areas, people with hearing impairment etc.. 3. PEOPLE ABILITY TO PARTICIPATE IN A STUDY: The health condition of some people may preclude their participation. Example, people with mental impairments, who are in coma. 4. DESIGN CONSIDERATIONS: it is sometimes advantageous to define a fairly homogeneous sample as means of controlling extraneous variables. CONTD..
  10. 10.   Sample may be defined as representative unit of target population which is to be worked upon by researchers during their study.  Quantitative researchers often select samples that will allow them to achieve stating conclusion validity and generalize their result. They therefore develop a sampling plan that specifies in advance how study participants are to selected and how many to include.  Qualitative researchers make sampling decision during the course of data collection based on information & theoretical need & typically do not develop a formal sampling plan in advance. SAMPLE
  11. 11. YOU

×