taking a sample from people who are available at the time the study is carried out and fit the criteria you are looking for.
easy method, quick to carry out.
Can be biased as your are only using a small part of the target population.
Self selected sample
Self selected sampling consists of participants becoming part of a study because they volunteer to take part e.g. in response to an advert.
-access to a variety of people/participants.
-Biased, participants WANT to do, may be well motivated people.
-people may want a reward.
The sampling technique which is defined as a sample in which every member of the target population has an equal chance of being chosen. e.g. choosing names from a hat.
-Unbiased, all participants have an equal chance of selection.
-hard to carry out.
-some people may refuse to take part affecting validity.