Question

 

Sampling

Process of sampling selection and generalization

Sampling definitions

Populations

Sample elements

Inclusion and exclusion criteria

Use of sampling criteria

Answer 1

A sample refers to a smaller, manageable version of a larger group. It is a subset containing the characteristics of a larger population. Samples are used in statistical testing when population sizes are too large for the test to include all possible members or observations. A sample should represent the population as a whole and not reflect any bias toward a specific attribute.

Sampling is a process used in statistical analysis in which a predetermined number of observations are taken from a larger population. The methodology used to sample from a larger population depends on the type of analysis being performed, but it may include simple random sampling or systematic sampling.

Process of sampling selection and generalisation;

1. Identify the Target population (Population of interest)

Target population refers to the group of individuals or objects to which researchers are interested in generalizing their findings. The target population is the group of individuals or objects, from which the sample might be taken.

2. Select a sampling frame

Sampling frame is the group of individuals or objects from which researcher will draw his/her sample. It is the list of all units in a study population from which the sample is taken.

3. Specify the sampling technique

Sampling can be done through probability (random selection) or non-probability (non-random) technique.

4. Determine the sample size

The sample size is simply the number of units in the sample. Sample size determination depends on many factors such as time, cost, facility. In general, larger samples are better, but they also require more resources.

5. Execute the sampling plan

Once population, sampling frame, sampling technique and sample size are identified, researcher can use all that information to choose his/her sample.

Generalization refers to the extent to which findings of an empirical investigation hold for a variation of populations and settings.Probability sampling procedures are considered effective to increase generalization of a study. Using a sample of participants who are representative of the population is key for making generalization from sample to population.

In statistics, a population is a set of similar items or events which is of interest for some question or experiment. A statistical population can be a group of existing objects or a hypothetical and potentially infinite group of objects conceived as a generalization from experience.A population is an entire pool from which samples are drawn.

Sampling element: is the unit of analysis or case in a population - can be a person, a group, an org, an arrest that is being measure.

The inclusion criteria identify the study population in a consistent, reliable, uniform and objective manner. The exclusion criteria include factors or characteristics that make the recruited population ineligible for the study. These factors may be confounders for the outcome parameter

Sampling criteria refers to the essential characteristics of a subject and respondent such as ability to read and write responses.Sampling criteria shapes the selected sample and provides the basis by which the sample is selected, that is the specific characteristics based on which the selection is made.Sampling criteria is essential as the whole population cannot be studied and the sample makes the research effective in cost and provides precise data.