Advantages and disadvantages of snowball sampling

The sample can be controlled according to some sample characteristics, which is suitable for finding some people who are very rare in the population.

The cost of investigation is greatly reduced, but this cost saving is at the expense of the quality of investigation. The whole sample is likely to be biased, because the list of those individuals comes from those who were originally investigated, and they may be very similar, so the sample may not represent the whole population well. In addition, if the respondents are unwilling to provide personnel for the investigation, then this method will be blocked. If the overall situation is not large, sometimes it will be close to saturation in a few times, that is, people who visit later will introduce people who have already visited. However, it is very likely that there are still many individuals who cannot be found in the end, and some individuals are deliberately omitted by the provider for some reasons. Both of them may have some noteworthy properties, which may lead to errors and cannot guarantee representativeness. Snowball sampling is the most suitable sampling method when the members of a particular population are difficult to find. For example, it is very suitable for obtaining samples of homeless people, migrant workers and illegal immigrants.