These magma plumes rise to the surface and form chains of volcanoes. Composite volcano magma contains more silica, SiO 2, than that of a shield volcano and is therefore stickier (more viscous). This stickiness plugs up the volcano, causing pressure to build-up. The result is an explosive, dangerous eruption.
It results in a biased sample, a non-random sample of a population (or non-human factors) in which all individuals, or instances, were not equally likely to have been selected. If this is not accounted for, results can be erroneously attributed to the phenomenon under study rather than to the method of sampling.
Definitions A sample is the group of people who take part in the investigation. The people who take part are referred to as âparticipantsâ. Sampling is the process of selecting participants from the population. The target population is the total group of individuals from which the sample might be drawn. Generalisability refers to the extent to which we can apply the findings of our research to the target population we are interested in.