Definición Selection method

Usually with a larger population, not all units of observation can be analyzed. Therefore, a smaller sample is drawn from the population, whereby the survey results are representative of the entire population. It is possible to create the sample utilizing three main types of selection: the random selection, the conscious and systematic selection (see quota sample) and the arbitrary selection. Random samples are used for the most part but systematic selection is also partly used for representative surveys. The random selection does not allow for conclusions with regards to the population. Examples of the arbitrary selection are most of the online surveys, selective customer interviews, surveys amongst radio listeners, and so on.