Random (probabilistic) tests

[samiaseo222]

As the name suggests, this selection system involves the use of randomization tools. The researcher has no influence on the selection process and all individuals in the target group have the same chance of participating in the study. As part of randomized trials , several techniques are also distinguished.

The first is simple random selection. It is the lithuania email list simplest of the random methods and consists of selecting an adequate number of units from the population being analyzed.

Another method is stratified random sampling. The first step in this method is to characterize the population structure based on a particular characteristic or combination of characteristics. An appropriate number of units must then be drawn from each stratum so that the sample structure matches the population structure.

Example:

If in a given population the number of smokers is 45% and the number of non-smokers is 55%, the researcher, taking into account addiction as a characteristic that configures the structure of the population, must extract the number of smokers and non-smokers so that in the extracted sample they represent 45% and 55% respectively.

The third method is systematic random sampling. It consists of establishing a specific frequency to extract individuals from the population, for example, one in ten people from the study group will be selected.

Selection by sets, as another technique included in a random survey, is used in the absence of a complete list of units in the population being analysed. It is necessary to draw teams (they can be, for example, localities, institutions, schools) to obtain lists of their members and, from these, a random draw is made.